Poster Session Abstracts POSTERS–Saturday 106th Annual International Conference of the American Society for Horticultural Science Millennium Hotel, St. Louis, Missouri

All posters are displayed in the Poster Hall, located in the Illinois/Missouri/Meramac rooms. The number in parentheses ( ) preceding the poster title corresponds to the location of the poster within the Poster Hall. Presenting authors are denoted by an asterisk (*).

(42) Rheological Properties of Water-soluble Crop Physiology/Physiology: Polysaccharide in Peach Gum from Cross-Commodity Almond (Prunus dulcis) Saturday, 25 July 2009 12:00–12:45 pm Sen Wang Central South University of Forestry and Technology, Changsha; wangq- (41) Growth and Salinity Tolerance of Zinnia elegans [email protected] When Irrigated with Wastewater from Two Distinct Lin Zhang Central South University of Forestry and Technology, Huann 410004; Growing Regions in California [email protected] Christy T. Carter* Deyi Yuan* Tennessee Tech University, Cookeville, TN; [email protected] Central South University of Forestry and Technology, Changsha; yuan- Catherine Grieve [email protected] U.S. Salinity Laboratory, Riverside, CA; [email protected] Qiuping Zhong Using recycled greenhouse effluents to irrigate salt-tolerant floral crops Central South University of Forestry and Technology, Changsha; wangq- provides an economic and environmental benefit for growers. Produc- [email protected] ers are able to reduce their direct use of high quality water for certain Yina Li crops and simultaneously reduce or prevent groundwater contamina- Central South University of Forestry and Technology, Changsha; wangq- tion. We selected Zinnia elegans as a potential salt-tolerant crop for [email protected] use in a recycled greenhouse system based on the known hardiness of The rheological properties of water-soluble polysaccharide in peach its wild relatives and because of its economic value to the floriculture gum from almond (Prunus dulcis) were studied in this paper in order industry. Using a completely randomized design of three replicates to provide more scientific technical parameters and references for with ten plants each, we exposed two Zinnia cultivars (Benary’s Giant developing peach gum as a kind of medicinal gum. This study was Golden Yellow and Benary’s Giant Salmon Rose) to increasing irriga- conducted on different material rates, temperatures, shaking times, tion water salinities with electrical conductivities (EC) of 2.0 (control), pH values, and salinities, respectively. The mathematical model of -1 4.0, 6.0, 8.0, and 10.0 dS·m , and two ionic water compositions that shear rate with material rate and shear stress was Y = 0.069X12 + simulated dilutions of sea water (typical of well-waters or degraded 0.035X2 – 1.174, R2 = 0.942. The mathematical model of shear rate waters in coastal growing regions) and concentrations of Colorado with temperature and shear stress was Y = 4.936X12 + 0.0232X2-1.688, River water (typical of tailwaters present in the inland valley areas of R2 = 0.937. The mathematical model of shear rate with shaking time + - 2+ 2+ + Southern California). We determined Na , Cl , Mg , Ca , K , total-P, and shear stress was Y = 0.005192X13-0.14073X12 + 1.249045X1 and total-S concentrations in leaves. Stem length, stem diameter, in- + 0.036546X2 – 3.64429, R2 =0.9543. The effects of pH value on the florescence diameter, ray length, plant weight, number of leaves, and rheological properties in the supernatant of peach gum were compara- time to flower were measured at harvest. Ion and morphological data tively complicated with a varying range of 3~11 and the shear rate for each cultivar were analyzed with a two-way fixed-effects GLM showed a change trend of saddle model. The mathematical model of ANOVA and a Tukey’s post-hoc procedure was used to determine shear rate with the concentration of NaCl and shear stress was Y = differences between individual means. Both cultivars showed similar –0.03744X1+ 0.01293X2, R2 = 0.998. The mathematical model of trends with respect to ion accumulation in leaves as concentrations shear rate with the concentration of CaCl2 and shear stress was Y = 2+ + - 2+ + of Mg , Na , Cl and total-S tended to increase and Ca , K , and 0.025789X1 + 0.01619X2, R2 = 0.999. The mathematical model of total-P tended to decrease as salinity of the irrigation water increased. shear rate with the concentration of sorbic acid potassium and shear 2+ Significant two-way interactions were found for Mg (P < 0.001), stress was Y = 0.0795X1 + 0.0173X2, R2 = 0.998. In sum, the mate- + - K (P < 0.0001), Cl (P < 0.01), total-P (P < 0.05), and total-S rial rates, temperatures, shaking times, and pH values significantly (P < 0.01) for “Salmon Rose”. Significant two-way interactions were affected the rheological properties in the supernatant of peach gum. found for Mg2+ (P < 0.0001), K+ (P < 0.0001), Cl- (P < 0.01), and The concentrations of NaCl and CaCl2 also significantly affected total-S (P < 0.001) for ‘Golden Yellow’. Morphological features of both the rheological properties expect the concentration of sorbic acid cultivars decreased as salinity increased in the irrigation solutions for potassium. both water types. A minimum stem length (45 cm) and inflorescence diameter (approximating 8 cm) were found at the highest salinity, in- Specified Source(s) of Funding: Scientific Research Fund of Hunan dicating that marketable flowers can be produced with saline irrigation Provincial Education Department (08C929) waters at least as high as 10 dS·m-1.

HORTSCIENCE, VOL. 44(4), JULY 2009 1083 (43) Oleocellosis Damage of Fruitlets in (45) Pollination and Growth Regulators on Late Season Mechanical Harvested Productivity of Olive Tree Under Dessert ‘Valencia’ Trees Does Not Affect Fruit Quality Conditions in México Juan Carlos Melgar* Raul Grijalva-Contreras* Citrus Research and Education Center, University of Florida, Lake INIFAP, Caborca Sonora 83600; [email protected] Alfred, FL; [email protected]fl.edu R. Macias Duarte INIFAP, Caborca Sonora 83600; [email protected] Jill Dunlop Citrus Research and Education Center, University of Florida, Lake A. Lopez Carvajal Alfred, FL; [email protected]fl.edu INIFAP, Caborca Sonora 83600; [email protected] Fabián Robles Contreras James P. Syvertsen INIFAP, Caborca Sonora 83600; [email protected] Citrus Research and Education Center, University of Florida, Lake Alfred, FL; [email protected]fl.edu M.J. Valenzuela Ruiz INIFAP, Caborca Sonora 83600; [email protected] Oleocellosis or oil spotting of citrus fruit, is a common injury on the F. Nuñez Ramirez flavedo caused by mechanical damage during harvesting and han- ICA-UABC, Caborca, Sonora; [email protected] dling. Physical injury of oil glands of the peel allows the phytotoxic oil to injure the surrounding cells. Using ‘Valencia’ orange trees, we Olive production in the world reaches an annual average about of 12 evaluated the effects of winter time drought stress and late season million tons, of which 90% is for oil use and the rest for table olives. mechanical harvesting (MH) with a canopy shaker on oleocellosis of In Caborca, Sonora, however, 90% of the production is used for table green fruitlets of next year’s crop. MH removed about 20% to 50% of olives for the U.S. market. In this research we compared the effect of fruitlets depending on previous drought stress treatments and harvest- artificial pollination and growth regulator Bioforte on the Manzanillo ing date. Beginning one week after harvesting (13 June), oleocellosis cultivar. There were two applications of pollen, the first on 3 April at injury was evaluated on 240 fruitlets based on visual estimations of doses of 30 g·ha-1, when there was 15% flowering and the second on the percentage of surface injured. Tagged fruit were evaluated about 5 April at doses of 40 g·ha-1 when flowering was at 80%. The pollen every other month until late season harvest in May. In April, mature used was ‘Sevillano’. The Bioforte treatment was applied before flow- fruit quality including fruit size, juice content (%), total soluble solids ering (March 29) and was applied using 0.2%. The pollen application (°Brix) and acidity, was not affected by previous drought stress treat- increased statistically the olives yield, obtaining an average yield ments. Fruit surface injury decreased as fruit expanded and injuries of 2464 kg·ha-1 vs. 1273 kg·ha-1 in the control trees. The increased healed but blemishes did not disappear. Thus, fruitlet oleocellosis in yield when we applied pollen on olive tree ‘Manzanillo’ was of 94%. late season mechanical harvested trees did not increase fruitlet drop However, the Bioforte application did not affected yield. Fruit quality nor alter fruit quality. such as weight, diameter, length of the olive, as well as the pulp–pit relationship, had no statistical differences in pollination or by the ap- Specified Source(s) of Funding: University of Florida/IFAS plication of Bioforte.

(44) Phloem Development in Sweet Specified Source(s) of Funding: INIFAP Orange Pedicels (46) Comparison of Commercial Sunburn Libia Laskowski* Protection Products Universidad Centroccidental Lisandro Alvarado, Barquisimeto, Lara; Ines Hanrahan* [email protected] WTFRC, Wenatchee, WA; [email protected] Phloem development in the pedicel determines the contribution of Tory R. Schmidt assimilated to the fruit, limiting its growth, nevertheless the related Washington Tree Fruit Research Commission, Wenatchee, WA; histological information is incomplete. Consequently, the differentiation [email protected] of phloem in samples of pedicels of Citrus sinensis L. var ‘Valencia’ James McFerson and ‘Salustiana’ was studied. During Phases I and II of fruit growth a Washington Tree Fruit Research Commission, Wenatchee, WA; mcferson histological study at the light microscope and scanning electron micro- @treefruitresearch.com scope was made. As a result, during the anthesis the vascular bundle Sunburn is the primary physiological cause of apple cullage in presented a small portion of protophloem and agreeing with Phase I of Washington, sometimes damaging up to 50% of the fruit in a given growth metaphloem was developed, formed by sieve-tube members of orchard. Losses occur both as surface damage as well as predisposi- simple sieve plate and these with numerous pores surrounded by callose. tion to storage disorders. Trials were carried out from 2005 to 2008 to At the end of Phase I, the primary phloem was increased consider- evaluate and compare the efficacy of commercially available sunburn ably and showed external fibers and obliterated protophloem. During protectants and to evaluate their ease of cleanup on a packing line. Phase II of growth differentiation of vascular cambium was observed Materials tested included: Cocoon, Eclipse, Fruit Shield, Invelop, and the phloem presented sieve-tube elements in long radial series, Raynox, Raynox Plus, Sun Guard, and Surround WP. All materials fibers ring development toward the interior of the phloem (beginning were applied four times throughout the season starting in early July; by metaphloem) and widened rays of parenchyma. At the end of the applications were made consistent with product labels for concentra- study, the secondary phloem with clear capacity of conduction was tion and use of adjuvants. At harvest, individual fruit was graded for limiting the ring of cells immediate to the vascular cambium, forming sunburn according to the Schrader/McFerson system (0 = clean, 6 = a ring of little thickness but of increased perimeter that adjusted to necrosis). All materials tested increased the percentage of sunburn-free the growth in circumference of pedicel during the secondary growth. fruit, enabling packers to move more fruit into the highest grade and The two varieties studied have similar histological development of increasing the returns for individual growers. We evaluated standard phloem, with small chronological variations. warehouse washing and rinsing of fruit on a research packing line,

1084 HORTSCIENCE, VOL. 44(4), JULY 2009 since residues of protectants can cause marketing problems. Visible frequently increased with effective chemical thinning. Reflective

residues were observed before placing fruit on the line and after 24 ground covers, such as Extenday™ or Daybright™, increase light POSTERS–Saturday hours of drying time. All materials cleaned easily off fruit flanks. available for photosynthesis, especially in lower, shaded portions of Residues remained in the stem bowls at significantly higher levels tree canopies. We have found this technology consistently increases for kaolin clay and calcium carbonate-based products, which would individual fruit size, as well as frequently improving overall yields be commercially acceptable in most cases. in apple, cherry, pear, peach, and nectarine orchards. Improved fruit color and quality due to reflective ground covers have facilitated (47) Effects of Ethylene Associated Compounds on fewer picks in some instances. Best results are typically obtained by In Vitro Growth and Differentiation of Cymbidium season-long application. We continue to explore impacts of partial sinense Rhizomes in Media for Rhizome Propagation season placement and carryover effects from year to year on vegeta- tive and reproductive vigor. and Shoot Differentiation Yao-Chien Alex Chang* (49) Soluble Fertilization with Ammonium-Calcium National Taiwan University, Taipei 10617; [email protected] and the Effect on Production of Vegetative Shoots Jhen-Ying Pan in Mexican Lemon [Citrus aurantifolia (Christ.) National Taiwan University, Taipei 10617; [email protected] Swingle] Nean Lee Marcelino Bazán-Tene National Taiwan University, Taipei 10617; [email protected] Universidad de Colima, Tecomán, Col.; [email protected] The gaseous plant hormone, ethylene, can induce a great range of plant Tirzo Noé Tejeda-Chávez responses in growth and development. In tissue culture, ethylene may Universidad de Colima, Tecomán, Col.; [email protected] promote or inhibit shoot formation, depending on species. Rhizome José María Anguiano-Cárdenas culture of Cymbidium sinense in cytokinin-free medium resulted in Universidad De Colima, Tecomán Colima; [email protected] rhizome proliferation but shoot differentiation in cytokinin-added medium. In this study, we investigated the effects of 1-aminocyclo- Javier Farias-Larios propane-1-carboxylic acid (ACC), aminooxyacetic acid (AOA), and Universidad de Colima, Tecomán, Col.; [email protected] Salvador Guzmán-González AgNO3 on shoot formation in rhizome culture. Rhizome sections of Cym. sinense ‘Rui Bao’ × Cym. sinense ‘Guang Hua Die’ was used as Universidad de Colima, Tecomán, Col.; [email protected] plant material; each chemical was tested at concentrations of 0, 50, and José Gerardo López Aguirre* 100 μM. Ethylene evolution was monitored by gas chromatography. Universidad de Colima, Tecomán, Col.; [email protected] Supplementing ACC in rhizome propagation medium promoted rhizome The producers of Mexican lemon have serious problems to produce growth and branching; adding AgNO suppressed rhizome growth but 3 fruit in winter. The information on the nutritional handling of the plant, increased shoot differentiation and growth. In shoot differentiation the pruning and hydric stress, to stimulate the vegetative shoot, is low. medium, adding ACC significantly inhibited shoot and root growth, Therefore, it is necessary to evaluate practical alternatives, to induce the while AgNO increased shoot growth. These results implied that 3 emission of vegetative and floral shoot, in order to obtain a better yield, ethylene may promote rhizome growth but inhibit shoot formation in and better good quality fruits in winter. For this reason, the effect of Cymbidium sinense, thought it should be further confirmed. The addition the liquid fertilization with ammonium-calcium of the Mexican lemon of ACC or AgNO increased ethylene evolution. It seemed that AgNO 3 3 was evaluated, for the stimulation of floral and vegetative sprout and to increased ethylene synthesis but inhibited ethylene action. Adding 50 increase to the number of flowers and fruits. The treatments consisted or 100 μM AOA in both media resulted in suppressing rhizome and of applying: 1) 0 ammonium; 2) 0.25 and 0.08 ammonium/calcium; shoot growth; it may be attributed to that these concentrations were 3) 0.375 and 0.12 ammonium/calcium; and 4) 0.5 urea. The obtained too high and caused toxicity. results shown significant statistical difference (P 0.05) in the number Specified Source(s) of Funding: National Science Council (NSC 97- of vegetative shoots/tree in treatment with 0.25–0.08 Ammonium- 2313-B-002-019) Calcium, with 2.5 times, with respect to the test and two times more than treatment with 0.5 of urea, at 30 days after application. Number (48) Programs to Increase Fruit Size and Yields in of vegetative shoots/tree in treatment 0.25–0.08 Ammonium-Calcium, Stone Fruit was increased 2.5 times, respecting to test. Therefore, nutrition of the Ines Hanrahan* Mexican lemon with liquid Ammonium-Calcium fertilized in level WTFRC, Wenatchee, WA; [email protected] 0.25–0.08, stimulated to a greater emission of vegetative shoots because they were increased 2.5% of flowers and fruits respecting to test, for Tory R. Schmidt the production in winter. Washington Tree Fruit Research Commission, Wenatchee, WA; [email protected] Specified Source(s) of Funding: Universidad de Colima James McFerson Washington Tree Fruit Research Commission, Wenatchee, WA; mcferson (50) Phenolic Content, Antioxidant Capacity and @treefruitresearch.com Cytotoxicity of Whole and Fractioned Pawpaw The most important determinant of profitability for soft fruit growers Extracts in Washington is consistent cropping of large target fruit. The Washing- Hideka Kobayashi* ton Tree Fruit Research Commission (WTFRC) has tested programs to Kentucky State University, Frankfort, KY; [email protected] adjust crop load and improve light distribution in the canopy over the Changzheng Wang past eight seasons in commercial stone fruit orchards in Washington. Kentucky State University, Frankfort, KY; [email protected] Our results indicate that chemical blossom thinning of stone fruit can Kirk Pomper be achieved by a variety of chemicals. Ammonium thiosulfate (ATS) Kentucky State University, Frankfort, KY; [email protected] has been the most consistent performer and individual fruit size is

HORTSCIENCE, VOL. 44(4), JULY 2009 1085 Pawpaw (Asimina triloba), a deciduous species of the eastern U.S., Fungal decay is a serious problem during postharvest storage and bears the largest edible fruit of all native trees. Pawpaw fruit, rich in marketing of berry fruits. Several plant volatile oils were evaluated for phenolic and antioxidant components, has been also identified as a their effectiveness in reducing decay and maintaining quality of berry major source of anticancer acetogenins. The objective of the study fruits. Linalool, p-cymene, carvacrol, anethole, perillaldehyde, cinnamic was to investigate the cytotoxicity of lyophilized pawpaw extract and acid, and cinnamaldehyde were found to be effective in suppressing phenolic rich fraction. Extracts used in this study include the whole mold growth in blueberries during storage at 10 °C. Combinations of extract (W), Fraction 2 (F2) and Fraction 5 (F5). Brine shrimp assay carvacrol and p-cymene or linalool and p-cymene significantly retarded was used to assess toxicity of these extracts. Pawpaw pulp was extracted decay in raspberries. Treatment with carvacrol, anethol, or perillaldehyde with 100% acetone twice, and then lyophilized. Acetonic (AcOH) also significantly increased the levels of fructose, glucose, and citric extract was first made with fruit pulp of popular pawpaw cultivars, acid in blueberries. The major anthocyanin in blueberries, malvidin- ‘PA Golden’ and NC-1, which was lyophilized and then reconstituted 3-galactoside, was enhanced by carvacrol, anethole, perillaldehyde, with double distilled water (DDH2O), followed by fractionation with cinnamic acid, and cinnamaldehyde, but not by linalool or p-cymene. different solvents in the order of DDH2O, 50% methanol (MeOH), 100% Higher free radical scavenging capacities were found in blueberries MeOH, 100% AcOH and 50% AcOH. Fractioned extracts were lyophi- treated with carvacrol, anethol, or perillaldehyde compared to untreated lized and phenolic content (PC) and antioxidant capacity (AC) were fruit as measured by oxygen radical absorbance capacity (ORAC) and estimated with Folin-Ciocalteu assay and ferric reducing/antioxidant hydroxyl radical (.OH). Further studies are required to evaluate the power (FRAP) assay. Absorbance readings for both Folin-Ciocalteu sensory quality of berry fruits treated with these plant volatile oils. (760 nm) and FRAP (595 nm) assays were recorded up to 2 hrs. F5 Specified Source(s) of Funding: U. S. Department of Agriculture of NC-1 had the greatest PC (1189.4 gallic acid eq. μg/sample mg) and AC (4903.3 Trolox eq. μmol/sample ml) of four pawpaw factions (53) Retrograde Vesicles from the Vacuole Regulate examined. PC and AC of F2 were much lower than those of F5 for both cultivars. Brine shrimps were subjected to five different concentrations Tonoplast Surface Area During Sucrose Uptake by of fractions for cytotoxicity testing, resulting in low mortality rate. The Fluid Phase Endocytosis present findings suggest that these phenolic rich two pawpaw fractions Ed Etxeberria* do not contain high amounts of cytotoxic acetogenins. University of Florida, Lake Alfred, FL; [email protected]fl.edu Specified Source(s) of Funding: USDA 1890 Capacity Building Pedro Gonzalez University of Florida, Lake Alfred, FL; [email protected]fl.edu (51) Performance of Rabbiteye Blueberry Javier Pozueta (Vaccinium ashei) Cultivars in North Alabama CSIC/Nafarroako Unibertsitate Publikoa, Nafarroa; [email protected]fl.edu Elina Coneva* During transport of external solutes from the apoplast to the vacuole Auburn University, Auburn, AL; [email protected] of storage cells by fluid phase endocytosis (FPE), vesicles originating Jeff Sibley at the plasmalemma merge with the tonoplast to release their contents. Auburn University, Auburn, AL; [email protected] The merging of endocytic vesicles with the vacuole results in a larger Arnold W. Caylor surface area/volume ratio than when separated, resulting in dilution of Alabama Agricultural Experiment Station, Auburn, AL; vacuolar contents. To concentrate solutes in the vacuole, a mechanism(s) [email protected] to reduce tonoplast surface area must exist. Three mechanisms have been proposed: 1) Retrograde vesicle formation. 2) Autophagic tubes. An experimental plot was established at the North Alabama Research 3) Tonoplast autolysis. The possibility of retrograde vesicles during FPE Horticulture Center, Cullman in December 2006 to evaluate the per- was investigated using red beet hypocotyls for their red and fluorescent formance of twelve rabbiteye (Vaccinium ashei) cultivars in North vacuolar pigment, which would identify any structure of vacuolar origin. Alabama’s environment. Six well established rabbiteye cultivars includ- Red beet hypocotyl tissue was incubated in sucrose solution for 24 h ing Brightwell, Tifblue, Powderblue, Baldwin, Premier, and Climax, as to induce FPE. After 24 h, protoplasts were generated and observed well as six newly released cultivars, namely Alapaha, Ochlocknonee, under confocal laser scanning microscopy. Induction of endocytosis by Montgomery, Ira, Onslow, and Yadkin were compared in the present sucrose resulted in the formation of numerous vacuole-derived vesicles study. The overall objective of this study is to investigate the vegetative as evidenced by betacyanin fluorescence. Diverse fluorescence intensi- growth and the cropping potential of an array of rabbiteye cultivars. ties of exocytic vesicles reflected their chronological formation as result Data were collected to evaluate and characterize fruit quality traits of of betacyanin dilution during FPE. Addition of endocytic inhibitors the selected cultivars. The results from our study suggest that rabbiteye during incubation with sucrose prevented the formation of exocytic cultivars Montgomery, Climax, Premier, and Alapaha had an early vesicles. The data strongly support the existence of a mechanism by ripening season, whereas Onslow, Yadkin, and Ira fruit ripened late in which vesicular structures pinch-off the vacuole reducing tonoplast the season. Baldwin, Premier, and Tifblue had the largest berries with surface area, and therefore, increasing the vacuolar concentration of an average berry weight of 1.7 g, while Montgomery and Brightwell FPE transported solutes. had the smallest berries of 1.2 g in 2008. Our data suggest that Alapaha, Brightwell, and Montgomery berries had soluble solids above 17.0%, (54) Influence of Mineral Nitrogen and while the sugar content of Tifblue was 14.5%. Alapaha blueberry pro- Glycine Concentrations on Growth and Nitrogen duced the highest yield of 3.9 kg/bush in 2008, followed by Tifblue, Yadkin, Ira, and Onslow with an average yield of over 2.7 kg/bush. Assimilation Enzymes of Tomato (Solanum lycopersicum) Seedling Under Aseptic Hydroponic Specified Source(s) of Funding: HATCH Cultivation (52) Maintaining Quality and Reducing Decay of Danfeng Huang* Berry Fruits with Plant Volatile Oils Shanghai Jiaotong University, Shanghai 200240; [email protected] Chien Wang* Tida Ge USDA–ARS, Beltsville, MD; [email protected] Shanghai Jiaotong University, Shanghai 200240; [email protected]

1086 HORTSCIENCE, VOL. 44(4), JULY 2009 Shiping Wang Hiroyuki Fukuoka

Shanghai Jiaotong University, Shanghai 200240; [email protected] National Institute of Vegetable and Tea Science, Mie 514-0113; POSTERS–Saturday [email protected] The experiments undertaken here were designed to determine different - + N forms applied as mineral nitrogen (NO 3-N, NH4 -N) and organic N Lettuce big-vein disease is a soil-borne viral disease found in major (glycine ) for the growth and nitrogen assimilation enzymes activities lettuce production areas worldwide. We have developed a transgenic of tomatoes. A tissue culture flask experiment with sponge as substrate lettuce line with resistance to the disease by introducing the inverted was established in tissue culture greenhouse with two different geno- repeats of the coat protein gene of Mirafiori lettuce virus (MiLV). In this types tomato (Lycopersicon esculentum, Shenfeng918 and Huying932) study, the transgenic lettuce was evaluated for biosafety assessment by seedling in vitro hydroponic culture under aseptic conditions. N was comparing its characteristics with those of a parental non-transformed - + applied in nutrient solutions at 3.0 mM NO 3-N, 3.0 mM NH4 -N and cultivar ‘Kaiser’. There was no significant difference between the trans- and a control receiving no N , but glycine as organic N at 4 different genic and the non-transgenic lettuce in pollen fertility, pollen dispersal, N-application concentration (0, 1.5, 3.0, 6.0 mM). Our results showed seed productivity, seed dispersal, dormancy, germination, growth of that the total plant N and biomass of the 2 tomato cultivars treated with seedlings under low or high temperature, chromatographic patterns of mineral and organic N was significantly greater (P < 0.05) than the leaf extracts, or effects of lettuce plants on growth of broccoli or on control treatment. The higher glycine concentration been given, the soil microflora. There was a significant difference in pollen size, but the higher total N and biomass were observed. Tomato plants could grow difference was small. The length of cotyledon of the transgenic lettuce well in conditions of glycine supply. The highest dry matter weights was a little shorter than that of ‘Kaiser,’ while there was no difference and total N we detected in 6.0 mM glycine concentration. There had in other morphological characteristics examined. Next we detected the significant differences between two cultivars (Shengfen918 and huy- CP gene and the npt II gene (kanamycin resistance gene) by PCR in

ing932). After 21 days of sterile incubation, all treatments significantly the transgenic lettuce of T1, T2 and T3 generations. The CP gene was enhance soluble protein content in shoot and root compared with detected in the transgenic lettuce of all generations. On the other hand, + control which no N receiving treatment. For TFAA, NH4 -N or Gly-N the npt II gene was detected in T1 plants, but not in the transgenic lettuce - treatments significantly increased in shoot and root, NO 3-N treatment of T2 or T3 generation. DNA sequences flanking T-DNA insertions in

had little significant effect compared with control treatment. Compared the transgenic lettuce of T2 generation were determined using inverse to control treatment, SN, AC and 3.0 Gly treatments all significantly PCR, and the result indicated that the right side of the T-DNA including - decreased GS activity in shoot and root, NO 3-N treatment significantly the npt II gene has been truncated in the transgenic lettuce. + decreased shoot GPT activity, while NH 4-N and Gly-N treatments had no significant effect on it, while amino acid-N treatment significantly (311) Isolation of a MYB Transcription Factor increased NADH-GDH, GOT and GPT activity in root compared Regulating Red Coloration of the Skin of - + with mineral N (NO 3-N, NH 4-N) treatment. NADH-GDH activity in Apple Fruit shoot and root, GOT and GPT in root enhanced sharply when Gly-N Sornkanok Vimolmangkang* concentration in the nutrient solution increased. Furthermore, ammonic- University of Illinois at Urbana-Champaign, Urbana, IL; assimilation enzymes activity in root were higher than that in shoot. [email protected] These results strongly suggest that agricultural plants (e.g. tomato) could effectively use organic nitrogen directly from organic nitrogen Yuepeng Han sources (e.g., glycine). Growth and nitrogen assimilation enzymes of University of Illinois at Urbana-Champaign, Urbana, IL; yphan@illinois. edu tomato seedling response to organic nitrogen (e.g., glycine) supply might be related to genotypes and concentrations of organic nitrogen. Schuyler Korban Further studies such as the contribution of organic nitrogen uptake to University of Illinois at Urbana-Champaign, Urbana, IL; korban@uiuc. the nitrogen nutrition and formation of the competitions between plants edu and microbes are recommended. The skin color of apple fruits is an important determinant of fruit quality. The red coloration of the skin is attributed to accumulation Genetics/Germplasm/Plant Breeding: of anthocyanins, belonging to a class of secondary metabolites in the flavonoid biosynthesis pathway, that are also potent antioxidants. Fruit Biotechnology skin coloration is regulated mainly by transcription factors (TFs) present Saturday, 25 July 2009 12:00–12:45 pm upstream of the anthocyanin biosynthesis cascade. MYB transcription factors are known to play roles in the regulation mechanism in the upstream cascade. It has been reported that transcription factors At- (310) Evaluation of a Transgenic Lettuce with MYB11 and AtMYB12 in Arabidopsis influence expression of several Big-vein Disease Resistance for Biosafety Assessment genes in flavonoid biosynthesis, including CHALCONE SYNTHASE, Yoichi Kawazu* CHALCONE ISOMERASE, FLAVONONE 3-HYDROXYLASE, and National Institute of Vegetable and Tea Science, Mie 514-0113; FLAVONOL SYNTHASE1. An apple EST contig potentially encod- [email protected] ing MdMYB11 has been identified by BLASTing an Arabidopsis AtMYB11 sequence against our apple EST database. Specific primers Yuji Noguchi are then designed based on the contig sequence, and used to screen National Institute of Vegetable and Tea Science, Mie 514-0113; an apple BAC library. A total of six positive apple BAC clones have [email protected] been identified and classified into two groups based on the size of Masaharu Kubota PCR products. This indicated presence of more than a single copy of National Institute of Vegetable and Tea Science, Mie 514-0113; the AtMYB11 in the apple genome. Two BAC clones, from different [email protected] groups, have been picked, and subjected to subcloning to recover whole Hidekazu Ito genomic DNA sequences. Here, we report on the genomic structure of National Institute of Vegetable and Tea Science, Mie 514-0113; the apple MdMYB11 gene as well as its expression profile. [email protected] Specified Source(s) of Funding: Illinois Council for Food Research

HORTSCIENCE, VOL. 44(4), JULY 2009 1087 (312) Full Length cDNA Sequence of Pear (Pyrus component is eleostearic acid (9,11,13-octadecatrienoic acid) that is bretschneideri Rehd.) S29-RNase and S29-Allele a conjugated trienoic fatty acid. It is readily oxidized when exposed to air, which resulted in formation of the unique polymer. To isolate Identification the genes related to tung oil synthesis and examine their expression Lin Zhang* patterns in V. fordii, we constructed a cDNA library using the develop- Central South University of Forestry and Technology, Huann 410004; ing seed tissues of V. fordii ‘duiniantong’ and picked out 3,107 clones [email protected] randomly for sequencing on the 5’-end to construct the EST library. Xiaofeng Tan We then performed homology comparison with nucleic acid NR da- Central South University of Forestry and Technology, Hunan 410004; tabase. The results indicated that 2,205 cDNA sequences were highly [email protected] homological to these sequences of other plant species in database of Donglin Zhang NCBI. A total of 482 different genes had been identified preliminarily University of Maine, Orono, ME; [email protected] and 342 clones possibly represented genes with unknown function. The Yan Shen sequences related to tung oil synthesis had delta 12 oleic acid desatu- Central South University of Forestry & Technology, Huann 410004; rase (FAD2), omega-3 fatty acid desaturase, 3-ketoacyl-CoA thiolase, [email protected] beta-ketoacyl-ACP synthase I, enoyl-acyl-carrier-protein reductase, Deyi Yuan esterase/lipase/thioesterase family protein, polyunsaturated fatty acid Central South University of Forestry and Tech, Huann 410004; yuan- synthase subunit B, enoyl-CoA hydratase/isomerase family protein, [email protected] and etc. Seed storage protein had caleosin, oleosin, legumin, albumin, and etc. There are lots of ribosomal RNA and pollen allergen genes. Chinese white pear (Pyrus bretschneideri Rehd.) belongs to Rosaceae Many sequences corresponded to transfer protein, gene expression, that exhibits characteristic gametophytic self-incompatibility. This type development regulation, resistance, growth substances and embryo of self-incompatibility is controlled by S-locus which carries a series - of multi-allelic alleles encoding S-RNases. To elucidate the function genesis, and etc., while the sequences of 338 genes related to universal of S-allele and the possible molecular mechanism of gametophytic substances biochemical metabolism were expressed only once. The V. fordii self-incompatibility in Chinese white pear, full length cDNA encoding numbers and trends of expressed genes were at the phase of seeds near to late embryogenesis. Establishing the EST library of V. S -RNase was cloned by rapid amplification of cDNA ends (RACE) 29 fordii and researching the genes related to the tung oil synthesis have approach from cultivars ‘Mili’ (S19S29) and ‘Zaomi’ (S19S29). The S29- RNase gene contained an open reading frame of 684 nucleotides encoding great significance to producing high-quality tung oil. 228 amino acid residues. S -RNase displayed typical sequence features 29 (314) SAD and FAD2 cDNA Genes Cloned from of rosaceous S-RNases, i.e. five conserved regions (C1, C2, C3, RC4 and C5) and a hypervariable (HV) region. At the deduced amino acid Camellia oleifera Abel Xiaofeng Tan level, S29-RNase showed 30% to 92% similarities with other rosaceous S-RNases. Phylogenetic analysis revealed that rosaceous S-RNases oc- Central South University of Forestry and Technology, Hunan 410004; curred before divergence of species, but after divergence of subfamilies [email protected] Maloideae and Amygdaloideae. Genomic PCR amplification with primer Hongpeng Chen combination FTQQYQ and anti-(I/T)IWPNV followed by digestion Central South University of Forestry & Technology, Hunan 410004; with the restriction enzyme AccII allowed effectively distinguishing [email protected]

S29-allele from other pear S-alleles. Dangquan Zhang Specified Source(s) of Funding: Scientific Research Fund of Central Central South University of Forestry & Technology, Hunan 410004; South University of Forestry & Technology (2008007B) and the Key [email protected] Project of State Forestry Administration (2006-12) Lin Zhang Central South University of Forestry and Technology, Huann 410004; (313) Analysis of Seed-Expressed Sequence Tags in [email protected] Vernicia fordii Donglin Zhang* Lushan Xie University of Maine, Orono, ME; [email protected] Central South University of Forestry & Technology, Huann 410004; Seeds of Camellia oleifera Abel produced high-quality edible oil, [email protected] important cosmetic ingredients, and bio-fuel, such as poly unsaturated Xiaofeng Tan fatty acids (about 90%). Oleic acid transformed from saturated fatty Central South University of Forestry and Technology, Hunan 410004; acid in the process of grease biosynthesis catalyzed by stearoyl-ACP [email protected] desaturase (SAD), then transformed into linoleic acid and other poly Lin Zhang* unsaturated fatty acids catalyzed by fatty acid desaturase (FAD) family Central South University of Forestry and Technology, Huann 410004; gradually. So the cloning SAD and FAD genes from C. oleifera are very [email protected] important for revealing the lipids biosynthesis patterns and achieving Donglin Zhang molecular-aided breeding in C. oleifera. We constructed cDNA and University of Maine, Orono, ME; [email protected] EST libraries of C. oleifera and 3 copies of SAD gene and 3 copies Hongxu Long of FAD gene were obtained from the EST library. One of three SAD Central South University of Forestry and Technology, Changsha; EST clones was confirmed to be the full-length cDNA and named as [email protected] co-sad, and 3 FAD2 EST clones were not full-length cDNA by BLAST Jiao Hu with SAD and FAD genes from other plants via GenBank, DBJ and Central South University of Forestry and Technology, Changsha; vam- EMBL. Bioinformatics analysis showed that co-sad was 1579 bp in [email protected] length and contained an 1188 bp open reading frame (ORF) encoding 396 amino acids. However, there was no obvious signal peptide and Tung-oil tree (Vernicia fordii) is one of the high-value industrial oil trans-membrane structure in the deduced protein sequence. BLAST trees in China, whose seed has 52% to 64% oil-yields content. The results suggested that co-sad tung oil is widely used in painting and chemical industry. Its principal shared high homology with SAD genes

1088 HORTSCIENCE, VOL. 44(4), JULY 2009 from Jatropha curcas and Ricinus communis on protein level. The 3 [email protected]

FAD2 EST clones were not full-length cDNA by aligning with FAD Lushan Xie POSTERS–Saturday genes from other plants in GenBank, DBJ and EMBL. Based on the Central South University of Forestry & Technology, Huann 410004; constructed EST library of C. oleifera, a full-length cDNA of FAD2 [email protected] gene was obtained by methods of 5’RACE and overlap extension PCR Lin Zhang with total RNA extracted from C. oleifera ‘Yanggulao No.1’ seeds. Central South University of Forestry and Technology, Huann 410004; The gene was 1682 bp in length and contained an ORF encoding 382 [email protected] amino acids, which formed typical conserved domains of FAD2 and Donglin Zhang* showed high homology with those of other plant species. The results University of Maine, Orono, ME; [email protected] of 3D structure prediction indicated that the Co-SAD and Co-FAD2 were much more advantageous than other SAD and FAD2 in lipids Camellia oleifera Abel (Teaoil Camellia) is a most important woody biosynthesis. These results could explain the higher content of oleic acid plant for edible oil production in China. Its oil possesses higher nutri- and linoleic acid in C. oleifera than that of other oil plants theoretically ent and medicinal values. Based on the cDNA library generated from and could be applied for breeding high yield teaoil cultivars. mature seeds of ‘Yanggulao No. 1’, a full-length cDNA sequence of a gene, which consisted of 975 base pair (bp) and an open reading frame (315) Identification of Two Calmodulin cDNA Genes (ORF) of 621bp gene, was cloned. The gene encoded a protein (id: for Camellia oleifera Abel ACJ06541, predicted Mr of 22.24 kDa) of 207 amino acids. The gene was identified as cyclophilin gene because its nucleotied sequence Baoming Wang shared the similarity of 96% (843/877) with that of Camellia sinensis Central South University of Forestry & Technology, Hunan 410004; cyclophilin. The putative protein possesses peptidyl-prolyl cis-trans [email protected] isomerase (PPIase,EC 5.2.18.) activity and belongs to CyPB protein. Xiaofeng Tan Homology analysis indicated that its putative amino acid sequences Central South University of Forestry and Technology, Hunan 410004; shared high identity with those of other higher plant CyPs (e.g., 86% and [email protected] 82% identity of those of Nicotiana tabacum cyclophilin-like protein and Lin Zhang Arabidopsis thaliana cyclophilin protein). It also shows nearly 100% Central South University of Forestry and Technology, Huann 410004; conservativeness in the four residues (Arg-96, Phe-101, His-167 and [email protected] Tyr-162) of binding cyclosporn A (CsA) and catalysis. Prediction of Donglin Zhang* structure showed that it mainly contains an N-terminal signal sequence, University of Maine, Orono, ME; [email protected] beta sheet accompanying with alpha helixes, beta turns and numerous Camellia oleifera Abel is a woody shrub or small tree that has been random coils. The protein possesses an array of enzyme-binding sites, widely cultivated for its edible oil production in China. After establish- cyclophilin-type peptidyl-prolyl cis-trans isomerase signature, and ing the cDNA library using matured seeds of C. oleifera ‘Yanggulao a unique seven amino acid sequence KSGKPLH in numerous plant No.1’, the two full-length cDNA genes, 953 base pairs (bp) and 1024 cyclophilins. The gene was submitted to GenBank (GenBank access bp, were cloned and identified as the calmodulin genes. They were number: FJ377540) and was termed as co-cyp1 gene. The gene expres- named CaM1 and CaM2 because of their high similarity in nucleotides sion during the peak of lipid biosynthesis might protect cell against in the encoding regions of CaMs between the two cDNAs and other reactive oxygen species (ROS) damage. Therefore, it may be crucial higher plant CaM from GenBank (Prunus avium and Actinidia kolo- during both development and stress responsiveness. mikta). Both genes contained two opening reading frames (ORFs) of (317) Fertility Restoration of Buddleia Species by 450 bp with 25 nucleotide substitutions, encoding the identical protein of 149 amino acids (predicted Mw of 16.83 kDa). The characteristic In Vitro Chromosome Doubling is consistent with the hypothesis theory “multigenes possess identical Wenhao Dai* amino acid sequence.” The two amino acid sequences of the putative North Dakota State University, Fargo, ND; [email protected] CoCaM protein were highly homologous and conservative while com- Wei Sun paring with those of other higher plants. The protein was comprised North Dakota State University, Fargo, ND; [email protected] of 19 amino acids with pI (theoretical isoelectric point) of 4.10 and Victoria Magnusson should be classified into a hydrophilic and acidic protein. It possessed North Dakota State University, Fargo, ND; [email protected] the structure domains including four EF-hand domains and contained Yuanjie Su enzyme-binding sites. The putative protein had some degree of identity North Dakota State University, Fargo, ND; [email protected] among its hydrophilicity, flexible regions and antigenicity, and shows the high flexibility. The Blast analysis indicated that the protein shared Mitotic chromosome doubling using colchicines has been successful more than 94% amino acid sequence identity with those of other plant for many crop species. It was involved in the production of triploid CaMs. The two genes, severed as the transducer of Ca2+-dependent watermelons, tetraploid grapes, and some autopolyploid ornamental signals, were expressed during the peak of lipid biosynthesis, which species. Induced autopolyploids could enhance the crossability of two may be crucial during Camellia oleifera physiological processes of species, particularly if both are diploids. Amphiploids could be used to the immune responses to bacterial pathogens, gene expression, protein restore some fertility of a totally sterile F1 hybrids thus to facilitate further synthesis, cell proliferation and apoptosis. backcrossing and introgression. In this study, chromosome doubling of three Buddleia sterile lines, B. marrubifolia × (B. davidii × B. crispa), (316) Cloning Cyclophilin cDNA Gene from B. marrubifolia × B. crispa, and B. marrubifolia × B. alternifolia, was Camellia oleifera Abel carried out to restore their fertility. Based on the field observation, these Xiaofeng Tan three lines are sterile. In vitro shoot tips and nodes were treated with Central South University of Forestry and Technology, Hunan 410004; colchicine solution at 0, 0.01, 0.1, and 1 mM for 1, 2, and 3 d. After [email protected] the treatment, the explants were washed in sterile distilled water and -1 Baoming Wang transferred into the Petri dishes containing MS medium plus 20 g l Central South University of Forestry & Technology, Huann 410004; sucrose with 0.5–2.5 μM BA for shoot recovery. Results showed that

HORTSCIENCE, VOL. 44(4), JULY 2009 1089 the shoot recovery rate increased as the concentration of colchicines Nahla Bassil and treatment time decreased. Plant recovery was also affected by USDA–ARS-NCGR, Corvallis, OR; [email protected] genotype in which B. marrubifolia × B. alternifolia was the most toler- Species identification using a short DNA sequence, i.e., DNA barcod- ant to colchicine treatment. The effect of colchicine was also observed ing, has been successful in animals due to the rapid mutation rate of during the in vitro rooting period with a decrease of rooting rate as the their mitochondrial genome. In plants, several potential barcode loci concentration and treatment time increased. Shoots with 3-4 opened have been proposed and evaluated. We chose to focus on two potential leaves were rooted in vitro and then transferred into the potting mix. regions, the chloroplast PsbA-trnH spacer and the nuclear ribosomal Acclimated plants were grown in the greenhouse for several months internal transcribed spacer (ITS). The objective of this study was to and eventually grown outside of the greenhouse. More than 500 plants analyze these two regions to determine their application in barcod- have been developed from these three lines by in vitro chromosome ing Fragaria species. PsbA-trnH was successfully amplified and doubling. Seeds were collected from these plants. The seed germination sequenced in 26 Fragaria accessions representing 19 species with an rate will be determined for fertility verification. Chromosome number average sequence length of 400 bp. Fifty ITS sequences representing of the plants with viable seeds will be counted for further verification 19 Fragaria species were analyzed in this study. Forty-two of these of ploidy. Other traits will also be evaluated. ITS sequences were available from GenBank. The remaining eight ITS (318) Substantial Equivalence Evaluation of regions representing seven species were successfully amplified and sequenced with an average sequence length of 607 bp. Kimura two CMV-Resistant GM Red Pepper in Terms parameter (K2P) distances ranged from 0–1.9 within species, and from of Fatty Acid Composition 0–4.4 between species. The range and average of the K2P distances Sunita Basnet between species was higher in the ITS (0–4.4%, 0.016 on average) than Soonchunhyang University, Asan; [email protected] the PsbA-trnH (0–3.5%, 0.011 on average). The range of the within Shiva Ram Bhandari species K2P distances (0–1.9) overlapped with the between species K2P Soonchunhyang University, Asan; [email protected] (0–4.4) which limits the use of DNA barcoding in Fragaria. The ITS neighbor joining tree clustered three tetraploids, F. tibetica Staudt & Kyu-Hwan Chung Dickore, F. corymbosa Losinsk and F. gracilis Losinsk. together. The Chung-Ang University, Anseong, 456-756; [email protected] ITS and PsbA-trnH neighbor joining trees revealed a close relationship Ki-Hyun Ryu between the fourth tetraploid used in this study, F. orientalis Losinsk, Seoul Women’s University, Seoul, 139-744; [email protected] and the decaploid, F. iturupensis Staudt. The phylogenetic resolution Young-Sang Lee* of Fragaria species using nuclear and chloroplast genome regions has Soonchunhyang University, Asan; [email protected] remained low. Complete chloroplast genome sequencing is now pos- As a part of testing substantial equivalence of genetically modified (GM) sible due to parallel sequencing technology and sample multiplexing. peppers, CMV-resistant GM peppers were cultivated in two different This technique may prove useful in identifying genomic regions that fields, harvested at two different stages, separated into two parts: pericarp are more phylogenetically informative for Fragaria species. and seed + placenta parts, and their fatty acid composition was compared (278) Fertility Improvements in Primocane-fruiting to native pepper line. In the case of pericarp 10 fatty acids could be de- tected and linoleic (35.14% to 37.74%), palmitic (23.54% to 24.15%), Blackberry (Rubus L. spp.) Genotypes and linolenic acids (17.78% to 20.21%) were major components. Among Alisha Ruple* 10 detected, GM peppers showed significant difference in one major University of Arkansas, Fayetteville, AR; [email protected] fatty acids: linoleic acid (35.14 %) as well as in two minor fatty acids: John R. Clark stearic (3.98 %) and palmitoleic (0.77%) acids with the differences of University of Arkansas, Fayetteville, AR; [email protected] (–) 2.6%, (–) 0.24%, and (+) 0.4 %, respectively compared to native M. Elena Garcia line. Similarly, 11 fatty acids could be found in seed + placenta part with University of Arkansas, Fayetteville, AR; [email protected] major composition of linoleic (69.69% to 72.77%), palmitic (13.45% to 15.48%), and oleic (9.25% to 10.04%) acids. Among 11 detected, Variation in berry set and fruit size of the recently introduced primo- palmitic acid (15.47%) and arachidic acid (0.31 %) showed significant cane-fruiting (PF) cultivars has been observed, particularly in diverse difference by (+) 2.03 % and (+) 0.05%, respectively compared to na- climates. Therefore, there is a need to assess overall fertility and heat tive one. In conclusion, most of the fatty acids showed no statistically tolerance of this new type of blackberry. Five PF genotypes were tested significant difference with their native line with some exceptional cases, for fertility in a field setting using primocane flowers with three pol- and even in such cases, the differences were less than 3%, indicating lination treatments. Treatments included open-pollinated undisturbed, the biological unimportance of such differences and hence suggest the emasculated selfed, and emasculated and cross pollinated. Berry set GM peppers being equivalent to their native line. was not significantly different between cross- and self-pollination treatments or genotypes. The open-pollinated undisturbed flowers had Specified Source(s) of Funding: BioGreen 21 (20070301034010) the highest berry set and emasculated selfed flowers had the lowest. Berry set among pollination treatments ranged from 44 to 84%. Cross Genetics/Germplasm/Plant Breeding: pollination resulted in larger berries for ‘Prime Jim’® and APF-45. Rat- ing for drupelet set was higher for ‘Prime Jim’® and APF-59 for cross Viticulture and Small Fruits ® pollinationcompared to self pollination. ‘Prime Jim’ had significantly Saturday, 25 July 2009 12:00–12:45 pm lower berry set and drupelet set rating than the five other PF genotypes. Screening for heat tolerance in a field setting can take multiple seasons (277) DNA Barcoding in Fragaria Species or sites. Having a screening protocol to be used in a laboratory setting would be beneficial to breeding programs because of the amount of Wambui Njuguna* time that could be saved. In an effort to create a protocol, pollen from Oregon State University, Corvallis, OR; [email protected] six PF genotypes was placed on germination media and incubated at Kim E. Hummer three temperatures (23 °C, 30 °C, and 35 °C) for 48 hours. Media was USDA–ARS-NCGR, Corvallis, OR; [email protected]

1090 HORTSCIENCE, VOL. 44(4), JULY 2009 then examined for germinated pollen grains. There was no significant (280) Performance of an Elite Strawberry interaction between genotypes and incubation temperature. Signifi- Population Derived from Wild Germplasm of POSTERS–Saturday cantly more pollen germinated for APF-31, APF-45, and APF-59 than ‘Prime-Jim’®. Pollen germination decreased as temperature increased Fragaria chiloensis and F. virginiana for all genotypes. This suggests that higher pollen viability, and likely Travis Stegmeir* not improved heat tolerance, enhanced pollen germination. While this Michigan State University, East Lansing, MI; [email protected] study did not provide a successful heat tolerance screening protocol, Ryan M. Warner it did reinforce findings from the field study. Our results indicate that Michigan State University, East Lansing, MI; [email protected] self fruitfulness appears to be adequate in all PF genotypes evaluated Chad Finn and that the newer-generation genotypes show improvement in fertility USDA–ARS HCRL, Corvallis, OR; [email protected] over ‘Prime-Jim’®. James Hancock (279) Fruit-Rot Resistance in the American Michigan State University, East Lansing, MI; [email protected] Cranberry, Vaccinium macrocarpon Fragaria ×ananassa Duchesne ex Rozier, or the cultivated strawberry, Jennifer Johnson-Cicalese resulted from the accidental hybridization of two wild species, F. chi- Rutgers University, Chatsworth, NJ; [email protected] loensis (L.) Miller and F. virginiana Miller. In an attempt to recreate the cultivated strawberry, elite clones of F. chiloensis and F. virginiana Nicholi Vorsa* were crossed within species and then hybridized to produce several Rutgers University, Chatsworth, NJ; [email protected] reconstructed populations. Of these populations, FVC11 [(Frederick 9 × James J. Polashock LH 50-4) × (Scotts Creek × 2 MAR 1A)] segregated for several impor- USDA–ARS, Blueberry & Cranberry Res Lab, Chatsworth, NJ; james. tant horticultural traits. In Summer 2008, seasonal flowering patterns, [email protected] inflorescence number, inflorescence height, crown production, flower Cranberry fruit rot poses a serious economic threat to U.S. cranberry number, fruit size, yield, internal color, soluble solids, fruit firmness growers and is increasing in severity and scope. In New Jersey, crop and plant vigor were measured in this population. Progeny means were losses of 25% are common even with a full fungicide regimen. Fruit compared to those of the parental means and most traits exhibited trans- rot is caused by a dynamic complex of 10–15 fungal species; primarily gressive segregation, most notably yield and fruit weight. Significant Phyllosticta vaccinii, Physalospora vaccinii, Colletotrichum gloeospo- positive correlations were found between many of the production traits, rioides, Coleophoma empetri and Phomopsis vaccinii. We evaluated although significant negative correlations were observed between fruit our cranberry germplasm collection to identify potential sources of firmness and flowers per inflorescence, fruit firmness and soluble solids field fruit rot resistance. Fungicides were withheld in 2003 and 2004 and yield per plant and soluble solids. Overall performance scores were to provide extreme disease pressure, and accessions were rated for fruit assigned to each genotype by summing their relative performance for rot. Seventy percent of the 562 plots had severe rot, while 6% showed each trait in the population. Individuals were identified that combined some level of resistance. Visual ratings correlated with quantitative high values for fruit weight and yield with higher than average values assessments. Significant correlations were found between the 2003 for fruit color, firmness and soluble solids. Use of this population in and 2004 ratings (r = 0.80) and counts (r = 0.75). Three of the resistant breeding programs could help expand the genetic base of the cultivated accessions had previously been used in crosses and their progeny were strawberry with limited linkage drag. planted in a large evaluation trial. Fungicides were withheld in 2005- 2007 and the trial was evaluated each year for field fruit rot. In 2007, (281) Two Methods for Assessing Frost Tolerance in disease pressure was so severe that of the 1644 progeny evaluated Flowers of Highbush Blueberry Cultivars from 30 crosses (including four crosses with a resistant parent), 1085 Lisa Rowland progeny exhibited nearly 100% rot, while only 13 plots had a rating USDA–ARS, Beltsville, MD; [email protected] of ‘2’ (< 40% fruit rot). Families with a resistant parent had a higher Mark Ehlenfeldt* frequency of resistant progeny, indicating additive genetic effects and USDA–ARS, Blueberry & Cranberry Res Lab, Chatsworth, NJ; mark. the potential for improving resistance through breeding. However, a [email protected] few resistant progeny originated from susceptible parents suggesting Elizabeth Ogden non-additive variance for field fruit rot resistance also exists. Fruit USDA–ARS, Beltsville, MD; [email protected] cultured from susceptible and resistant cranberry plots had the same species of fruit rot fungi present, suggesting broad-based resistance. John Philips The current hypothesis is that the fruit rot fungi infect during bloom USDA–ARS, Wyndmoor, PA; [email protected] and then remain latent until the fruit ripening phase. Thus, in an effort D. Michael Glenn to identify a mechanism of resistance, we evaluated flowering char- USDA–ARS, Kearneysville, WV; [email protected] acteristics of resistant and susceptible accessions. No relationships Fumiomi Takeda were found between fruit rot resistance and bud development (starting USDA–ARS, Kearneysville, WV; [email protected] at initial bud break), %bloom, or flowering period. Studies are now Sensitivity of blueberry flowers to freezing temperatures differs underway to evaluate the polyphenolic profiles of resistant accessions, among cultivars and stages of bud development. Also, the frost testing starting early in fruit development. SCAR markers indicated that the technique and the duration at lethal temperature can have a dramatic resistant accessions in our germplasm collection are genetically diverse, effect on bud injury. Artificial frost tests should duplicate the types of offering multiple sources of resistance. The fruit rot-resistant plants spring frosts in the field. Freezing tests were conducted on detached have now been used in over 60 crosses with the ultimate objective of shoots with open flowers in a controlled freezing glycol bath and on developing high-yielding cranberry varieties with increased levels of whole plants with flowers in a radiation frost chamber for ‘Bluecrop’, fruit rot resistance. ‘Elliott’, ‘Hannah’s Choice’, ‘Murphy’, and ‘Weymouth’ highbush Specified Source(s) of Funding: USDA CSREES and SCRI blueberries. The freezing regimes enabled the expression of a range of frost damage symptoms in all the cultivars tested. Damage score

HORTSCIENCE, VOL. 44(4), JULY 2009 1091 data showed a clear, bi-modality with either no damage or damage to Jeff Kuehny corolla, stamen (anther sac and filament), style, and carpel. The corolla Louisiana State University, Baton Rouge, LA; [email protected]. was most sensitive to freezing temperatures, followed by anther fila- edu ments, style, ovary wall, and ovules. Injury to all parts of flowers with Matthew D. Taylor expanded corolla occurred at higher temperatures than on flowers that Longwood Gardens, Kennett Square, PA; [email protected] were less developed (corolla unexpanded). This study compared two With the increased interest in sustainable production practices, numer- methods for examining the effects of freezing temperatures on blueberry ous biocontainers produced from nonpetroleum-based plastics or from flower injury. Convective and radiation freezing tests yielded similar organic components have come onto the market. The physical proper- results in assessing the susceptibility of blueberry cultivars and floral ties of various types of biocontainers were evaluated and compared parts at different stages of development to freezing temperatures. The to traditional plastic containers. Containers produced from rice hulls, cultivars were ranked for frost hardiness as follows: ‘Hannah’s Choice’ bioplastic and compressed paper had the highest dry and wet strengths > ‘Murphy’ > ’Weymouth’ > ‘Bluecrop’ = ‘Elliott’. and were similar to traditional plastic containers. Containers such as Specified Source(s) of Funding: Federal those made from straw and coconut fiber had low dry strength due to their flexible nature, but they retained a high level of wet strength. Con- (282) Transferability of Rubus Microsatellite tainers made from peat and wood fiber had the lowest wet strength of Markers for Use in Black Raspberry all the containers evaluated. Containers made from peat and wood fiber Michael Dossett* had the highest rate of water loss while traditional plastic, bioplastic Oregon State University, Corvallis, OR; [email protected] and rice hull containers had the lowest rate of water loss. Contain- ers made from peat had an average of 48% of the container surface Nahla Bassil covered by fungal and algal growth after 8 weeks in the greenhouse USDA–ARS–NCGR, Corvallis, OR; [email protected] environment. Containers made from dairy manure, straw and paper had Kim Lewers 2%, 3% and 3%, respectively, of the container surface covered with USDA–ARS BARC, Beltsville, MD; [email protected] algal and fungal growth after 8 weeks. Traditional plastic, bioplastic, Chad Finn coconut fiber and rice hull containers had no visible algal or fungal USDA–ARS HCRL, Corvallis, OR; [email protected] growth after 8 weeks. Microsatellites or simple sequence repeats (SSRs) are valuable as co- (180) Physical Properties of Growstones-, Perlite- dominant genetic markers with a variety of applications such as DNA fingerprinting, linkage mapping, and population structure analysis. To and PBH-Containing Root Substrates date, SSR marker development in Rubus has focused on red raspberry Michael Evans* (Rubus idaeus L., subgenus Idaeobatus) and more recently in blackberry University of Arkansas, Fayetteville, AR; [email protected] (Rubus L. subgenus Rubus). The objective of this study was to deter- Clint Metcalf mine the suitability of SSR markers developed in other Rubus species University of Arkansas, Fayetteville, AR; [email protected] for use in black raspberry (R. occidentalis L., subgenus Idaeobatus). The amplification and optimum annealing temperature of 109 Rubus Growstones are a light-weight aggregate produced from waste glass SSR primer pairs was determined in the black raspberry ‘Munger’ by bottles and containers. They are designed to serve as an alternative to gradient polymerase chain reaction. A panel of 15 cultivars and wild such aggregates as perlite and parboiled rice hulls (PBH) in providing black raspberry accessions was used to evaluate these SSR primers for drainage and air-filled pore space in root substrates (substrates). As for polymorphism visually, using 3% agarose gel electrophoresis. compared to horticultural perlite, Growstones had a higher air-filled Transferability of SSR markers was better for those developed in red pore space (53%) than perlite (30%) and a lower air-filled pore space raspberry than blackberry, with a higher percentage successfully am- than PBH (68%). Growstones and perlite had similar water-holding plifying products (88% and 74%, respectively) and a higher percentage capacities (34% and 32%, respectively), but Growstones had a higher of polymorphic markers among those amplifying products (32% and water-holding capacity than PBH (21%). Growstones had a higher bulk density (0.19 g·cm-3) than both perlite (0.17 g·cm-3) and PBH 22%, respectively). The percentage of polymorphic markers was also -3 higher for those developed from red raspberry genomic libraries (35%) (0.10 g·cm ). Sphagnum peat-based substrates containing 10% to 30% than from blackberry genomic libraries (29%) while the percentage for Growstones had a similar or higher air-filled pore space than substrates those developed from genic regions (EST, cDNA) was similar (20% and containing equivalent amounts of perlite, but a lower air-filled pore space 19%, respectively). Of the 25 red raspberry SSR markers tested, seven than those containing equivalent amounts of PBH. Increasing the amount amplified products that were polymorphic, while 12 of the 83 blackberry of any of the aggregates increased the amount of air-filled pore space. SSR markers tested were polymorphic. These 19 SSR markers will be Substrates containing 15% or more Growstones had higher water-hold- useful for studying diversity in black raspberry germplasm. ing capacities than equivalent perlite- and PBH-containing substrates. Increasing the amount of any of the aggregates decreased the water- Specified Source(s) of Funding: Federal Competitive holding capacity of the substrates. Substrates containing Growstones had higher bulk densities than equivalent perlite- and PBH-containing Horticultural Crops Culture and Management: substrates. The days required for Growstones-containing substrates to dry from container capacity to 50% moisture content and to complete Floriculture Crops drying was similar to that of equivalent perlite-containing substrates Saturday, 25 July 2009 12:00–12:45 pm but higher than that of equivalent PBH-containing substrates. (181) Modeling Daily Water Use of Abutilon and (179) Physical Properties of Biocontainers Lantana Based on Environmental Conditions Designed for Greenhouse Crops Production Jongyun Kim* Michael Evans* University of Georgia, Athens, GA; [email protected] University of Arkansas, Fayetteville, AR; [email protected] Marc Van Iersel

1092 HORTSCIENCE, VOL. 44(4), JULY 2009 University of Georgia, Athens, GA; [email protected] higher disease incidence. The MIXED procedure of the SAS system

Efficient water use and better irrigation control are increasingly im- was used to perform analysis of variance for disease incidence data from POSTERS–Saturday portant in ornamental production. Due to a lack of information about each evaluation date separately. Pairwise comparison of means was the water needs of plants, excessive irrigation is common. Excessive performed using Fisher’s LSD (α = 0.05). At both locations ‘Whirligig’ irrigation reduces profits because of unwanted leaching, runoff, power exhibited high variability including both the highest and lowest bacte- consumption, and labor. Lantana camara ‘Silver Mound’ and Abuti- rial leaf spot ratings with the following means: 3.7 (RAREC 19 June), lon × hybridum ‘Fairy Coral Red’ were grown from rooted cuttings 4.4 (RAREC 27 June), 5.3 (RAREC 6 July), 5.9 (Snyder 19 July) and in a greenhouse with 0.50 m3·m-3 volumetric substrate water content 7.2 (RAREC 25 July) . ‘Zowie! Yellow Flame’ consistently exhibited for 10 weeks. We used an automated irrigation system, which allowed the most severe incidence of bacterial leaf spot with its season low control and quantification of daily water use (DWU), to quantify (3.8) on 27 June at Snyder and its highest (7.3) at RAREC on 6 July. environmental effects on DWU of abutilon and lantana. Temperature, At the Snyder farm location on 27 June and 1 August no ratings were relative humidity, PPF, and daily light integral (DLI) were measured significantly different for bacterial leaf spot. Bacterial leaf spot was throughout the experiment. Daily maximum vapor pressure deficit more prevalent at the start of the season and powdery mildew severity increased dramatically later in the season. ‘Zowie! Yellow Flame’ con- (VPDmax) was calculated from the daily maximum temperature and the minimum relative humidity. The observed DWU ranged from 23 to 299 sistently exhibited the lowest severity of powdery mildew throughout mL/plant for abutilon and from 32 to 315 mL/plant for lantana during the season, at both locations: 1.9 (RAREC 1 August), 1.4 (Snyder 11 the experiment. DWU was positively correlated with days after planting August) and 7.9 (Snyder 1 Sepember). Excepting RAREC on 31 Aug- est, when no ratings were significantly different for powdery mildew. (DAP), DLI, and VPDmax. Using multiple regression analysis, DWU was 2 2 ‘Oklahoma’ and ‘Peppermint Stick’ exhibited significantly high scores described as a function of DAP, DAP , DAP×DLI, and VPDmax (R = 0.95 and 0.94 for abutilon and lantana, respectively). Predictive models throughout the season at the two locations. that describe the daily water needs of greenhouse crops can be used to (183) Height Control of Six Ornamental Grasses make greenhouse irrigation more efficient, thereby reducing both the costs and environmental impact of greenhouse production. with Foliar Sprays of Trinexapac-ethyl or Uniconazole Specified Source(s) of Funding: Fred C. Gloeckner Foundation Sonali R. Padhye* (182) Zinnia Variety Evaluation for Powdery Mildew University of Florida, Milton, FL; padhye@ufl.edu and Bacterial Leaf Spot Judith K. Groninger University of Florida, Milton, FL; judegron@ufl.edu Jenny S. Carleo* Rutgers University, New Jersey Agricultural Experiment Station, Cape The objective of this study was to quantify the influence of foliar sprays May Court House, NJ; [email protected] of trinexapac-ethyl (TE; Primo Maxx) and uniconazole (Concise) on Daniel L. Ward height control of three ornamental grasses each from Cyperaceae (Carex Rutgers University, New Jersey Agricultural Experiment Station, Bridge- buchananii, Carex comans ‘Frosted Curls’, and Carex flagellifera ton, NJ; [email protected] ‘Toffee Twist’) and Poaceae (Cortaderia selloana ‘Rosea’, Miscan- Nicholas Polanin thus sinensis ‘Gracillimus’, and Muhlenbergia capillaris). Propagules Rutgers/New Jersey Agricultural Experiment Station, Bridgewater, NJ; were transplanted into 13-cm containers and grown in a polycarbonate [email protected] greenhouse at 25 ± 2.9 °C under natural photoperiods. Two and 3 weeks C. Andrew Wyenandt from transplanting, grasses from Cyperaceae and Poaceae, respectively, −1 Rutgers University, New Jersey Agricultural Experiment Station, Bridge- received 2 biweekly foliar sprays of TE at 220 mg·L or uniconazole −1 −2 ton, NJ; [email protected] at 20 or 40 mg·L . Spray volume of 1.89 L·m was applied and a non- Peter Nitzsche sprayed control was maintained. Ten plants per treatment were arranged Rutgers University, New Jersey Agricultural Experiment Station, Mor- in a completely randomized design. Plant height was recorded 0, 2, 4, ristown, NJ; [email protected] and 8 weeks after the initial treatment (WAIT). Data were analyzed using SAS’s PROC MIXED and pair-wise treatment comparisons George Wulster were made at P ≤ 0.05. The mean height of Cyperaceae grasses was Rutgers University, New Brunswick, NJ; [email protected] not influenced by any treatment in up to 4 WAIT. In 8 WAIT, the mean Pedro Perdomo height of C. buchananii treated with 20 mg·L−1 uniconazole was sup- Cleary Chemical Corporation, Dayton, NJ; [email protected] pressed by 16% than controls. On average, in 8 WAIT ‘Frosted Curls’ A performance evaluation of Zinnia (Zinnia elegans) was conducted treated with 20 and 40 mg·L−1 uniconazole were 13, and 8% shorter in the coastal plain (southern) and piedmont (northern) regions of New than controls, respectively. In 8 WAIT, mean height of ‘Toffee Twist’ Jersey to determine disease incidence and severity, and the hypothesis treated with 220 mg·L−1 TE and 20 and 40 mg·L−1 uniconazole was sup- that newer variety selections would display greater disease resistance pressed by 21, 24, and 20%, respectively than controls. Thus, overall, than ‘Benary’s Giant’, an industry standard in the cut flower market. uniconazole was more effective than TE in controlling height of the Five varieties, ‘Benary’s Giant’, ‘Oklahoma’, ‘Peppermint Stick’, Cyperaceae grasses. The mean height of ‘Rosea’ treated with TE was ‘Whirligig’, and ‘Zowie! Yellow Flame’ were included in this study. reduced by 13% than controls in 2 WAIT. Compared with controls, mean This field experiment was conducted as a 5 × 5 Latin square with the height suppression of ‘Rosea’ treated with TE and 20 and 40 mg·L−1 five cultivars in a one-way treatment structure, repeated at the Rutgers uniconazole was 23%, 15%, and 19% in 4 WAIT and 37%, 24%, and NJAES Agricultural Research and Extension Center in Bridgeton, NJ 32% in 8 WAIT, respectively. Mean height of ‘Gracillimus’ was not (coastal plain) and the Rutgers NJAES Snyder Research and Extension influenced by uniconazole in 8 WAIT however; TE suppressed it by Farm in Pittstown, NJ (piedmont). Zinnias were transplanted into the 17%, 27%, and 23% than controls in 2, 4, and 8 WAIT, respectively. field on 17 May 2006 in Bridgeton and 26 May 2006 in Pittstown. No No treatment influenced the mean height of M. capillaris in 2 WAIT. fungicides were applied during the growing season. Disease incidence However, on average, M. capillaris treated with TE was 14% and 35% of powdery mildew and bacterial leaf spot were measured using the shorter than controls in 4 and 8 WAIT, respectively. Thus, overall, TE Horsfall-Barrat rating scale (0–12), where higher numbers indicate was the more effective than uniconazole in controlling height of the

HORTSCIENCE, VOL. 44(4), JULY 2009 1093 Poaceae grasses. cultivars similarly. ‘Avalanche Lilac’ and ‘Dreams Burgundy Picotee’ had the greatest radicle growth rate but were considered as more heat (184) Acquired Stress Tolerance for Improving susceptible cultivars due to a significant reduction in radicle growth Landscape Survivability of Petunia rate under heat stress. ‘Avalanche Lilac’ was also regarded as the most Jennifer Mader* drought sensitive cultivar. The results from this study indicate that the Louisiana State University, Baton Rouge, LA; [email protected] SGST may be used to determine heat or drought tolerance but further research should be conducted to determine greenhouse and landscape Jeff Kuehny performance under heat or drought stress. Louisiana State University, Baton Rouge, LA; [email protected]. edu (186) Evaluation of New Poinsettia Varieties Jeffrey Beasley in Central Missouri LSU AgCenter, Baton Rouge, Louisiana; [email protected] Sanjun Gu* Standard greenhouse bedding plant production protocol may provide Lincoln University, Jefferson City, MO; [email protected] for alleviating heat stress if the environment is closely monitored. How- Theresa Blank ever, plants entering postproduction in the market and eventually the Lincoln University, Jefferson City, MO; [email protected] landscape often face an inconsistent environment and can be subject to long periods of stress. Preconditioned plants (acquired stress tolerance) Poinsettias (Euphorbia pulcherrima) are traditional plants for Christmas may greatly improve postproduction marketability and survival in the decorations. The objective of this trial was to evaluate and introduce landscape when exposed to a challenging environment. The objective some new poinsettia varieties or selections for Poinsettia growers and of this study was to determine the efficacy of acquired temperature consumers. Twenty-four poinsettia varieties/selections, including clas- tolerance by imposing heat shock during greenhouse production for sic red/pink or novel colored, were tested at the Lincoln University improving landscape survivability of Petunia ×hybrida. Nineteen Research Greenhouse located at Jefferson City, Mo. Rooted cuttings petunia cultivars from three plant classes (floribunda, grandiflora, or were planted in 6½" standard pots on August 20, using Premier Pro- spreading) were previously evaluated, where cultivars within the same mix with biofungicide. The trial was conducted as a Completely plant class and series were grouped as either best or worst overall Randomized Design with four replications. There were four individual landscape performance and then subjected to heat shock. Petunias plants per replication for each variety. Approximately 400 ppm N of were grown in a greenhouse at 30 °C and exposed to heat shock of 45 Peter’s Peat Lite Special 15–16–17 was applied weekly for the first °C for 4 hours, every 3 days, for 3 weeks. Weekly harvests showed a two weeks after planting and then the rate was reduced to 200 ppm and significant increase in flower count, flower size, internode length, leaf continuously applied weekly until November 25. Magnesium Sulfate area, leaf area ratio and relative growth rate regardless of heat shock and Sodium Molybdate were incorporated into the fertilizer solution exposure. However, the heat shock treatment significantly decreased once in mid-October and once in mid-November. Plant heights were shoot dry weight and absolute growth after three weeks of treatment. measured twice on October 26 and November 29. Response time (date Field performance evaluations of these greenhouse grown plants indi- of color changing) for all plants was recorded. On December 3, a team cated that some cultivars appeared to develop acquired stress tolerance of 36 faculty and staff, students, master gardeners and others evalu- based on the heat shock treatment. ated all varieties on bract color, foliage shape and proportion, overall appearance, and personal preferences. The finishing height was about (185) Development of a Rapid and Effective 33–40 cm for all varieties. Varieties Freedom Early Red, Early Joy Red, Screening Method for Basal Stress Tolerance of Freedom Early Pink, Autumn Red, Gala Red, Freedom Early White, Petunia ×hybrida and Eggnog changed colors much earlier than varieties Peppermint Twist, Winter Rose Early Red, and Winter Rose Early Pink. The top Miao Liu* three winners for the pink group were Freedom Early Pink, Freedom Louisiana State University, Baton Rouge, LA; [email protected] Peppermint, and Classic Pink; for the red group were Gala Red, Prestige Jeff Kuehny Early Red, and Advent Red; for the white group were Classic White Louisiana State University, Baton Rouge, LA; [email protected]. Freedom, Early White, and PX14001; and for the novel group were edu Eggnog, Peppermint Twist, and Winter Rose Early Red. The three most Jeffrey Beasley favorite varieties chosen by the 36 judges were 54-06, Snowcap and LSU AgCenter, Baton Rouge, Louisiana; [email protected] Ice Punch, which include two varieties in the novel group and indicate High temperature and drought stress are two of the greatest impediments people’s preference to innovative types. to bedding plant growth and development. The objective of this study was to develop a rapid and effective protocol for screening Petunia Crop Physiology/Physiology ×hybrida for basal heat or drought tolerance. A practical growth sys- Health Properties tem for measuring seedling growth, or seedling growth sensitivity test (SGST), was first established. Based on this protocol radicle growth rate Saturday, 25 July 2009 1:15–2:00 pm was chosen over hypocotyl growth as the most reliable and accurate measurement for the SGST. Nineteen petunia cultivars from three plant (84) Effect of Supplemental UV Light Exposure on classes (floribunda, grandiflora, or spreading) were previously evaluated, where cultivars within the same plant class and series were grouped as the Anthocyanin Content of Two Red Lactuca sativa either best or worst overall landscape performance and then subjected Cv. Outredgeous and Firecracker Grown Under to the SGST. Seeds were germinated in Petri dishes at 26 °C for 4 days Light Emitting Diodes and Fluorescent Lamps and then subjected to 5-h heat shock at a temperature of 40 °C or 6 d Sharon I. Edney* drought stress at an osmotic pressure of –0.8MPa stimulated by PEG Dynamac Corp., Kennedy Space Ctr., FL; [email protected] 6000 to determine heat or drought tolerance, respectively. The results Gary W. Stutte indicated heat or drought stress significantly affected the relative radicle Dynamac Corp., Kennedy Space Ctr., FL; [email protected] growth rate of seedlings. However, the imposed stress did not affect all

1094 HORTSCIENCE, VOL. 44(4), JULY 2009 Gerard J. Newsham marrubiin. Tissue was extracted for 24 hours at room temperature, dried

Limerick Institute of Technology, Limerick; [email protected] under air flow, resuspended in 80% methanol, and subjected to C-18 POSTERS–Saturday column chromatography. Marrubiin concentration was determined with The use of naturally occurring antioxidants can mitigate the effects of RP-HPLC with pure marrubiin as a standard. Storage of both leaf tissue radiation damage and enhance healing from oxidative damage which and extracts at –80 ºC had a marked effect on marrubiin concentration. may occur on long-duration space missions. Light quality can affect Marrubiin concentration decreased 24% over 4 weeks and was associated the content of bioprotective anthocyanins and change the antioxidant with a 2-fold increase in a compound whose retention time correlated value of salad crops grown in space. A series of experiments were to previous reports for premarrubiin. Heating of extracts to 30 ºC for conducted to determine the effect of both UVA and/or UVB light on the 3 days increased the marrubiin concentration by 76% with levels of anthocyanin concentrations of two different cultivars of red leaf lettuce. premarrubiin dropping to undetectable levels. These concentrations Lettuce was grown in controlled environment chambers (EGC M-36 remained stable upon further storage at either room temperature or Environmental Growth Chambers, Chagrin Falls, OH) at 23 °C, 65% RH –80 ºC. Marrubiin and premarrubiin concentrations differed with the and 1200 ppm CO . A 16 h light/ 8 hr dark photoperiod was maintained 2 type of solvent used during extraction. However, heating of extracts under either light emitting diodes (LEDS) or triphosphor fluorescent eliminated the differences producing high and stable levels of marrubiin lamps (TFP, Sylvania). Treatments consisted of 300 μmol·m-2·s-1 red for up to a 4 week period. LEDs only (640 nm) or 300 μmol·m-2·s TFP lamps only throughout development [(0-21 days after planting (DAP)] as controls. UVA (365 (86) Phenolic Content and Antioxidant nm peak, JKL (F8T5BLT) or UVB (312 nm peak, Phillips PL-S9W/01) supplemental light was added from 0–21. Acrykuc barriers were used Capacity of Native Teas to block transmission of UVA and UVB as the “control” treatment in Hideka Kobayashi* all experiments. A UV-transmitting acrylic (ACrylite OP-4) was used Kentucky State University, Frankfort, KY; [email protected] in the UVA and UVB treatments. Lettuce was harvested at 21 DAP Green tea (GT), made from Camellia sinensis (L.) Kuntze, is a rich and dry mass, leaf area, plant height, anthocyanin content, and oxygen source of phenolic compounds and has high antioxidant capacity. radical absorbance capacity (ORAC) value determined. Results show a Regular consumption of GT has been linked to various health benefits, significant increase in anthocyanin per gram in both cultivars with the including lowering cholesterol, weight loss, etc., and therefore interest addition of UVB light to the red LEDs. UVA was ineffective at induc- in GT has been steadily increasing. Despite current popularity among ing anthocyanin formation in cv. Outredgeous, but was inductive in cv. consumers, domestic production of GT is confined to South Carolina and Firecracker. ‘Firecracker’ exhibited enhanced anthocyanin even from Hawaii, and thus consumption largely depends on imported tea. Aside the supplemental transmission of UVA from TPF lamps through the from GT, various species have been used for tea. Of those, spicebush OP-4 acrylic. There was also a difference in the overall ORAC potential [Lindera benzoin (L.) Blume] is native to the eastern part of the U.S. in response to UVA and UVB in both cultivars. This suggests that there from Maine to Texas, and Navajo tea [Thelesperma megapotamicum are genotypic differences in UV sensitivity to anthocyanin induction in (Spreng. ) Kuntze] is distributed mostly in the western part of the U.S. lettuce which should be considered in any future development of salad from Oregon to Michigan. The objective of the study was to compare crop production systems for long duration space missions. phenolic content and antioxidant capacity of GT to those of teas made Specified Source(s) of Funding: Support provided by Core Technical from two native species that can be grown in many parts of the U.S. Capability (CTC) Program at NASA’s John F. Kennedy Space Center, Folin-Ciocalteu assay was performed to determine phenolic content of FL. FÁS (Foras Áiseanna Saothair), Ireland’s Training and Employ- all three teas, using gallic acid as a standard. Phenolic content of these ment Authority Science Challenge Program provided funding for G. teas were 19.0 (GT), 1.7 (spicebush tea, ST), 4.6 (Navajo tea, NT) in Newsham mg of gallic acid equivalent per 100 g of dry weight. Similarly, Ferric Reducing Antioxidant Power (FRAP) assay was performed to assess (85) Effects of Tissue Freezing, Storage Time antioxidant capacity of these teas, which were determined as 1068.1 and Temperature, and Extraction Conditions (GT), 34.1 (ST), and 263.2 (NT) expressed in μmol of Trolox equivalent per g of dry weight. While phenolic content and antioxidant capacity on Marrubiin Content of the Medicinal Plant, of two native teas were less than those of GT, domestic production of Marrubium vulgare these teas potentially creates potential opportunities for both farmers James W. Gegogeine* and health-conscious consumers. University of Georgia, Athens, GA; [email protected] (87) Identification of Biomarker Compounds Hazel Y. Wetzstein University of Georgia, Athens, GA; [email protected] in Muscadine Damayanthi (Dayan) Ranwala* Marrubium vulgare, white horehound, is a medicinal plant that exhibits Clemson University, Charleston, SC; [email protected] antispasmodic, analgesic, and anti-inflammatory activities, and is used in the treatment of gastrointestinal and respiratory disorders. One of Hannah Lane the active compounds is the furanic labdane diterpene marrubiin. Mar- Medical University of South Carolina, Charleston, SC; [email protected] rubiin is proposed to be formed from premarrubiin during extraction. Micheal Wargovich The objective of this study was to evaluate the effect of extraction and Medical University of South Carolina, Charleston, SC; wargovic@musc. storage conditions on the concentration of marrubiin. Specifically, edu extractions of fresh versus frozen leaf tissue, storage time and tem- Joseph D. Gangemi perature, and extraction solvent were compared. Fresh or frozen leaf Clemson University, Charleston, SC; [email protected] tissue was extracted in acetone. The effect of leaf and extract storage Muscadine phenolic compounds may have anti-oxidant and anti-inflam- time at –80 °C was assessed by assaying marrubiin content over time matory properties. In order to identify these compounds, muscadine for up to 4 weeks. In addition, the effect of acetone or ethanol extrac- (Vitis rotundifolia) pomace (cv. Noble) was acid hydrolyzed and ex- tion solvent on marrubiin content was compared using fresh leaf tissue. tracted using solid phase extraction. The flavonoid and anthocyanin Further studies evaluated the effect of heating extracts prior to analysis fraction (FAF) was analyzed for phenolic and flavonoid contents using because this is proposed to enhance the conversion of premarrubiin to

HORTSCIENCE, VOL. 44(4), JULY 2009 1095 colorimetric assays, and individual biomarker contents using high 2008. The samples were separated into the purple tender leaves, the performance liquid chromatography (HPLC). The FAF had greater green tender leaves, the tender stems, the mature leaves and stems. Each phenolic and flavonoid contents as compared to crude extract. The main group was homogenized and analyzed for dry matter and ash content. anthocyanins present were di-glucosidic delphinidins and cyanidins. The acetone extracts of the samples were analyzed for total phenol The FAF fraction was tested in two colon cancer cell lines to determine content according to the Folin-Ciocalteau method. The total phenol the anti-inflammatory nature of the muscadine biomarker compounds. content of the purple leaves at the tip of the vine was comparable to Preliminary studies using cell proliferation assays and flow cytometry that of blackberries analyzed under the same conditions. The mature data showed that this fraction decreased viable cell proliferation in HT- leaves have lower phenol content than the tender leaves and the stems 29 and HCT-15 cell lines and evidence of G1 arrest, indicating possible contained less than half as much phenols than tender leaves. These anti-inflammatory role of muscadine in colon cancer cells. results indicate that sweetpotato leaves, especially the tender tip of the vine with the purple leaves, can be a good source of phenol antioxidants, (88) Seasonal Variation in Essential Oil Constituents and sweetpotato greens can be used as a vegetable. of Japanese Spicebush Specified Source(s) of Funding: USDA-Evans-Allen Jun Pill Baek University of Massachusetts, Amherst, MA; [email protected] (90) Effect of Humic Substances on Biomass Kuen-Woo Park Production and Constituent Levels in Thyme Korea University, Seoul 136-701; [email protected] C.R. Juarez-Rosete L.E. Craker* Colegio de Postgraduados, Montecillo; [email protected] University of Massachusetts, Amherst, MA; [email protected] L.E. Craker* Japanese spicebush (Lindera obtusiloba Blume, family Lauraceae), a University of Massachusetts, Amherst, MA; [email protected] wild growing herb in Korea, Japan, and northeast China, has been used M.N. Rodriguez-Mendoza in traditional medicine (stems and bark), tea (young leaves), and food Colegio de Postgraduados, Montecillo; [email protected] (leaves) in Korea. The plant essential oil, extracted from leaves and J.A. Aguilar-Castillo stem, has a distinctive aroma, similar to ginger and the stem bark has Universidad Autonoma de Nayarit, Nayarit; [email protected] been used as an insect repellant. To determine the effect of collection season on constituency of the essential oil, the upper three leaves were Thyme (Thymus vulgaris L.), an aromatic and medicinal plant with collected three times (during the first week of June, August, and October) antioxidant, antimicrobial, and antifungal properties, is of considerable in the northern part of Gyeonggi-Do, South Korea, and extracted by interest to the pharmacological and food industry. To determine whether simultaneous steam distillation/solvent method using Likens-Nickerson humic substances would affect the growth and bioactive constituent ® apparatus. The extracted essential oil was analyzed using gas chroma- levels in thyme, plants from three companies (Botanical interest , Seeds ® ® tography-mass spectrometry (Agilent 6890N, 5975MSD, U.S.A.). Oil Depot and Thyme Garden ) were grown in plastic pots (500 cc) filled constituents were identified by comparison of the spectral data with with a greenhouse media (Farfad 3B mix) containing three levels of that in the NIST mass spectral library, ver. 2.0 (NIST, U.S.A.). The humic substances. The humic substances, sourced from HumiSolve ® ® essential oil concentration was highest in August. The concentration USA and TM-7 USA , were mixed in the dry media at 0, 0.5, 1.0, of major constituents in the oil showed little change, although α- and 1.5, and 2.0 percent. The interaction of humic substances with soil β-phellandrene, β-pinene, limonene, camphene, and caryophyllene moisture was monitored by maintaining sets of pots at 20, 40, and 60 oxide were slightly higher in October and caryophyllene was highest percent field capacity. To promote growth, the plants were fertilized -1 in August. with 50 mL of N-P-K (1 g·L of 17-5-24) weekly. Changes in plant growth and development were determined by measurements of plant Specified Source(s) of Funding: credit card height, fresh and dry weights, and essential oil content. Oil constituents were determined by gas chromatography, antioxidant activity was de- (89) Sweetpotato Leaves as a Source of termined using a DPPH assay, phenolic content and flavonoid content Antioxidant Phenols were determined using a spectrophotometer. Results indicate thyme Changzheng Wang* growth and development are affected by humic substances and water Kentucky State University, Frankfort, KY; [email protected] content of the growth media. Lingyu Huang Specified Source(s) of Funding: credit card Kentucky State University, Frankfort, KY; [email protected] Michael Bomford (91) Nutrient Content of Commercial Kentucky State University, Frankfort, KY; [email protected] Sweetpotato Cultivars Anthony Silvernail David H. Picha* Kentucky State University, Frankfort, KY; [email protected] Louisiana State University, Baton Rouge, LA; [email protected] Sweetpotato is one of the world’s most cultivated crops, and is grown Consumers are placing increasing importance on the nutritional qual- all over the world, especially in Asia and the Pacific. The leaves are ity of food products in making their purchasing decisions. Limited good forage for domestic animals, so consumption by humans is looked information is available on the nutrient content of the commercially down upon in some places as the food of the poor. However, because important sweetpotato cultivars marketed in North America and Europe. some varieties of leaves are high in protein, they can be an important Crude protein and mineral composition was determined in the roots food source for people eating a diet based on tubers and other grains of numerous orange and white flesh cultivars. Crude protein content in some countries. Chinese medicine also suggests sweetpotato leaves ranged from 1.18 g/100g fresh weight in ‘Garnet’ to 2.29 g/100g in have some medicinal properties, which may be related to the phenol ‘Bienville’. However, consumed in moderation, sweetpotatoes only antioxidants in them. The objective of this study was to determine the contribute a minor amount of protein to the diet. Potassium (K) was total phenol content of sweetpotato leaves. Leaves were collected from the principal macro element in all cultivars, followed by phosphorus the experimental farm of Kentucky State University in the summer of (P). The sweetpotato is a potentially good source of K to the diet. The

1096 HORTSCIENCE, VOL. 44(4), JULY 2009 K content ranged from 275 mg/100g in ‘Georgia Jet’ to 1220 mg/100g Periodically through the growing season, weed density, weed fresh

in ‘Garnet’. The P content ranged from 28 mg/100g in ‘Georgia Jet’ to biomass and hand weeding times were recorded. In comparison to POSTERS–Saturday 54 mg/100g in ‘Bienville’. The remaining macro elements were pres- MBPic, solarization alone was not effective in controlling weeds, or ent in lesser amounts, with roughly similar levels found in calcium, reducing the hand weeding time. Steam with or without solarization magnesium, and sulfur. ‘Diane’ was the cultivar that contained the resulted in weed control similar to MBPic. In comparison with control highest amounts of these macro elements. Iron and manganese were the and solarization alone, steam treatments with and without solarization principal minor elements found in all sweetpotato cultivars, followed were sufficient to control Verticillium. First year strawberry yields in by lesser amounts of zinc, boron, copper. Substantial differences in steam treatments were comparable to MBPic. micronutrient content existed between cultivars. Specified Source(s) of Funding: USDA, Cooperative State Research, Specified Source(s) of Funding: credit card Education and Extension Service (118) Occurrence of Xyllela fastidiosa and Its Vector, Horticultural Crops Culture and Management: Glassy-Winged Sharpshooter, in Selected Alabama Weed Control and Pest Management Orchards Saturday, 25 July 2009 1:15–2:00 pm Xing Ma* Auburn University, Auburn, AL; [email protected] (117) Steam and Solarization to Disinfest Soil in Elina Coneva California Strawberry and Cut-flower Production Auburn University, Auburn, AL; [email protected] Jayesh B. Samtani* Henry Fadamiro University of California, Davis, Salinas, CA; [email protected] Auburn University, Auburn, AL; [email protected] Celeste A. Gilbert John F. Murphy University of California, Davis, Davis, CA; [email protected] Auburn University, Auburn, AL; [email protected] Steven A. Fennimore Fenny Dane University of California, Davis, Salinas, CA; [email protected] Auburn University, Auburn, AL; [email protected] Krishna V. Subbarao A study to determine the occurrence of Xylella fastidiosa in five com- University of California, Davis, Salinas, CA; [email protected] mercially grown fruit crops in Alabama and identify the vector spe- Rachael Goodhue cies was initiated in 2008. Tissue samples from peach, plum, satsuma University of California, Davis, Davis, CA; [email protected]. mandarin, muscadine grape, and bunch grape were collected three edu times during the growing season. Sampling sites included commercial John B. Weber orchards in the Gulf Coast, Central, and North Alabama. An ELISA University of California, Davis, Salinas, CA; [email protected] test was conducted to detect the presence of X. fastidiosa. Plum groves showed the highest incidence of X. fastidiosa when compared to the With the phase-out of methyl bromide in California agriculture, there’s other crops in our study. At the end of the season (30 September), 100% an immediate need to evaluate and adopt feasible alternatives. Although of plum samples collected from the Gulf Coast and Central Alabama solarization can effectively kill soil-borne pests, the presence of fog and sites tested positive for the bacterium, whereas only 10% of the plum cool summer temperatures in Coastal California cause it to be a less samples collected from the North Alabama site tested positive. Sharp- reliable tool for pest control than chemical fumigation. The objective shooter vector populations were monitored on a bi-weekly basis during of this study was to evaluate steam in combination with solarization the growing season. Four vector species were collected and shown to for effective pest control in field-grown strawberry and cut-flower consist of Homalodisca vitripennis, H. insolita, Oncometopia orbona, production. Field studies were conducted at the Spence Research Farm and Graphocephala versuata. H. vitripennis appeared to be the most at Salinas, CA (strawberry) and at a commercial farm (cut-flower) at prevalent species. Peak trap capture of sharpshooters (98/trap) was Prunedale, CA in 2007–08 and 2008–09 seasons. Plot beds were 1.3 observed on 16 June in the Gulf Coast location and on 30 July (20/trap) to 1.8 m by 6.1 m long. Prior to treatment application, pathogen and in Central Alabama. However, very few sharpshooters were captured weed seed samples were enclosed in permeable nylon mesh bags and at the North Alabama site with a peak trap capture of 1.5/trap on 30 buried in experiment beds. Pathogen samples were buried at 45, 30 and July. As indicated by previous studies, sharpshooter populations and 15 cm depth and weed samples at 15 and 5 cm depth. These samples incidence of X. fastidiosa induced diseases in various fruit crops are were removed post-treatment and their viability determined using likely restricted to warmer locations. petri-dish assays for pathogens, and tetrazolium tests for weed seeds. Experimental design was a randomized complete block replicated Specified Source(s) of Funding: Department of Horticulture, Auburn six times. Treatments in the study included 67% methyl bromide + University 33% chloropicrin (MBPic, 67:33) at 392 kg·ha-1, control, solarization, steam, and steam + solarization. For steam + solarization treatments, (119) Tolerance of Selected Bedding Plants to Four beds were solarized two weeks prior to steam application and two Herbicides in Irrigation Water weeks after steam application. Prior to application of clear tarp for Lyn Gettys* solarization, beds were irrigated to bring soil moisture to sufficient University of Florida, Gainesville, FL; lgettys@ufl.edu levels to promote heat conduction. Steam was injected for sufficient W.T. Haller time to raise the bed temperatures to 70 °C for 20 min. After 20 min., University of Florida, Gainesville, FL; whaller@ufl.edu steam disinfestation was discontinued. Temperatures during steam and solarization process were monitored using temperature probes installed Begonia (Begonia semperflorens ‘Cocktail Whiskey’), vinca (Cathar- in beds at 45-, 30-, 15-, and 5-cm depths. The amount of fuel, time and anthus roseus ‘Sun Devil Extreme’), melampodium (Melampodium labor needed for treatment application were recorded. At the end of 4 paludosum ‘Million Gold’), and impatiens (Impatiens walleriana ‘Super week treatment period, strawberry and cut-flower were transplanted. Elfin’) were irrigated with water treated with quinclorac, topramezone,

HORTSCIENCE, VOL. 44(4), JULY 2009 1097 imazamox and penoxsulam to identify herbicide concentrations that application of the 0.07 kg·ha-1 a.i. rate of sulfosulfuron, 4 weeks after cause phytotoxic effects. Plants were irrigated four times over a 10- the first treatment. Sulfosulfuron was injurious to all species tested day period with the equivalent of 1.27 cm of treated water during each except rhododendron; however, the species exhibited varying degrees irrigation, then irrigated with tap water until they were harvested 28 of injury, and rate and number of applications was also important for days after the first herbicide treatment. Visual quality and dry weight the amount of injury. Dogwood and hydrangea showed the most injury data revealed that melampodium was the most sensitive of the bedding from the sulfosulfuron than any other species. The second application plants to quinclorac, imazamox and penoxsulam, whereas vinca was the of sulfosulfuron caused injury symptoms to either reappear or increase most sensitive species to topramezone. Noticeable reductions in visual in intensity. Halosulfuron did not injure hydrangea or rhododendron quality and dry weight of melampodium were evident after exposure whatsoever. All other species showed some injury to halosulfuron, to 240, 580, and 10 ppb of quinclorac, imazamox, and penoxsulam, but like sulfosulfuron, to varying degrees. respectively, while dry weight of vinca was reduced after exposure to Specified Source(s) of Funding: IR-4 private 110 ppb of topramezone. Current irrigation restrictions on imazamox, penoxsulam and topramezone are adequate to minimize damage to these bedding plants if herbicide-treated waters are used for four irrigation (121) Preemergence Weed Control in Container- events. However, irrigation restrictions should be established for quin- grown Herbaceous Perennials clorac to prevent damage to sensitive bedding plants such as vinca. James Klett* Specified Source(s) of Funding: Florida Fish and Wildlife Conservation Colorado State University, Fort Collins, CO; [email protected] Commission, Bureau of Invasive Species David Staats Colorado State University, Fort Collins, CO; [email protected] (120) Weed Control Trials on Selected Ornamentals During the 2008 season, three preemergence herbicides were applied at the Ohio State University to two container-grown herbaceous perennials and one woody plant Luke Case* and evaluated for weed control, phytotoxicity, and effect on plant The Ohio State University, Columbus, OH; [email protected] growth. The herbicides and rates were: BAS 659H G (dimethenamid + pendimethalin) 2.97, 5.94 and 11.88 kg ai/Ha; BAS 656H EC (dime- Hannah Mathers thenamid) 1.09, 2.18 and 4.36 ai kg/Ha; Mesotrione (Mesotrione EC) The Ohio State University, Columbus, OH; [email protected] 2.35, 4.70 and 7.05 kg ai/Ha; Broadstar 0.25G (flumioxazin) 0.42, 0.84 Kyle Daniel and 1.68 kg ai/Ha; V-10142G 0.84, 1.68 and 3.36 kg ai/Ha. Herbicides Ohio State University, Columbus, OH; [email protected] were applied to LITTLE TRUDY® Catmint (Nepeta ‘Psfike’PP18,904), Upender Somireddy MONGOLIAN BELLS® Clematis (Clematis integrifolia) and FROSTY Ohio State University, Columbus, OH; [email protected] ® Potentilla (Potentilla fruticosa ‘Monsidh’). Treatments were applied Dania Rivera twice with six weeks between applications. The entire experiment was The Ohio State University, Columbus, OH; [email protected] repeated twice with two weeks between the experiments. Plants were evaluated for phytotoxicity after one week, two weeks and four weeks Weed control continues to be a major expense for nursery growers, after applying herbicide treatments. In this study, BAS 656H EC was and many species still have few, if any options for chemical weed safe to use with Clematis and Potentilla at the recommended rate. control. Two trials to test for phytotoxicity were set up at The Ohio BAS 656H EC should only be used on Nepeta after it is established. State University, Columbus, Ohio. In the first trial, red maple (Acer BAS 659H G and Broadstar 0.25G were safe to use on all species rubrum ‘Sun Valley’), butterfly bush (Buddleia davidii ‘Nanho Blue’), tested in this study at the recommended label rate. Mesotrione was Japanese holly (Ilex crenata ‘Convexa’), Norway spruce (Picea abies), not acceptable for Clematis or Potentilla and marginal for Nepeta. red oak (Quercus rubra), lilac (Syringa ×tribrida ‘Lark Song’), yew V-10142 would not be recommended at any rate for any of the spe- (Taxus media ‘Runyan’), and Japanese tree lilac (Syringa reticulata cies tested. Generally, effective weed control was provided by BAS ‘Ivory Silk’) were treated with one of the following herbicides and 659H G, BAS 656H EC, Broadstar and Mesotrione. For treatments rates: dimethenamid-p + pendimethalin at 3.0, 5.9, and 11.9 kg·ha-1 with V-10142, weed efficacy (grasses in particular) was significantly a.i., dimethenamid-p (EC formulation) at 1.1, 2.2, and 4.4 kg·ha-1 less at the 1x and 2x rates. a.i., imazosulfuron at 0.84, 1.7, and 3.4 kg·ha-1 a.i., mesotrione – G at 2.4, 4.7, and 7.1 kg·ha-1 a.i., and flumioxazin at 0.42, 0.84, and 1.7 Specified Source(s) of Funding: IR-4 kg·ha-1 a.i. Dimethenamid-p (EC formulation) injured red maple with increasing rates with the highest rate providing higher than com- (122) Third Season Performance of Synthetic mercially acceptable ratings. The first application was much more injurious than the second application. The butterfly bush showed injury Ground Covers in Blackberries from both the imazosulfuron (especially at the higher rates) and the Donald Makus* mesotrione – G (at all rates). Mesotrione – G was also very injurious USDA–ARS IF & NR, Weslaco, TX; [email protected] to the Japanese holly, lilac, and yew at all rates. The highest rate of John L. Jifon dimethenamid-p (EC formulation) did injure the lilac, especially after Texas AgriLife Research at Weslaco, Weslaco, TX; [email protected] the second application. In the second trial, arborvitae (Thuja occidentalis Synthetic weed barriers, which have shown promise in a first fruiting ‘Smaragd’), viburnum (Viburnum plicatum tomentosum ‘Mariesii’), season ‘Kiowa’ blackberry (Rubus spp) planting near Monte Alto, TX hydrangea (Hydrangea macrophylla ‘Forever Pink’), Japanese holly (Lat. 26º 26’N), were evaluated for a second fruiting season in 2008. (Ilex crenata ‘Convexa’), daylily (Hemerocallis ‘Fathers Best White’), Weed removal times were significantly shorter and material integrity dogwood (Cornus sericea ‘Cardinal’), serviceberry (Amelanchier unaffected by time (Mar. 2006 to July 2008) in a black polypropylene canadensis ‘Rainbow Pillar’), boxwood (Buxus ‘Antarctica’), Norway with polyester blend (Dewitt Co., Sikeston, MO) and a nylon-reinforced spruce (Picea abies), and rhododendron (Rhododendron ‘PJM’) were white on black plastic (T-65, Reef Industries, Houston, TX). The white treated with sulfosulfuron at rates of 0.07 and 0.13 kg·ha-1 a.i. and plastic material improved early season and total season yield (49% halosulfuron at a rate of 0.07 kg·ha-1 a.i. One treatment was a second relative to bare soil), early season berry weight, fruit soluble solids

1098 HORTSCIENCE, VOL. 44(4), JULY 2009 (%), sugar:acid ratio and generated the lowest harvest season (May (124) Cultural and Chemical Weed Control

14 to June 25) soil temperatures at 10 cm compared to other weed In Newly Established French-American POSTERS–Saturday barriers and the bare ground treatment. The durability of the synthetic weed barriers, in an environment which typically receives about 0.15 Hybrid Grapes MJ/m2 of UV A + B per day in mid-summer, appeared to be propor- Harlene Hatterman-Valenti* tional to product cost. In a separate 8 week greenhouse pot experiment North Dakota State University, Fargo, ND; h.hatterman.valenti@ndsu. to evaluate the effectiveness of these materials to reduce water loss, edu all synthetic fabrics were better than bare soil and the white plastic Collin P. Auwarter was superior to all materials used. When plants were introduced to North Dakota State University, Fargo, ND; [email protected] the system, (in a parallel experiment conducted at the same time), the Field research was conducted at the NDSU Agricultural Experiment ability to measure these water use differences gravimetrically between Station Research site near Kindred, ND to evaluate the influence of treatments was lost after four weeks; and no significant plant growth cultural and chemical weed management strategies on weed control and differences (P > 0.08) in top or root dry weight between bare soil and plant growth in newly established grapes. The trial was arranged as a weed barrier materials were observed in the eighth week. split plot with three cultural (landscape fabric, wheat straw, and wood chips) and one chemical (flumioxazin at 0.375 lb ai/A + oryzalin at 3 (123) Field Evaluation of Herbicide and Mulch lb ai/A) weed management strategies as the main plot and four grape Combinations for Weed Control Efficacy cultivars (DM8521, MN1131, MN1200, and St. Croix) as sub-plots, replicated three times. Two year old grape plants were transplanted May Upender Somireddy* 25, 2008 with two plants per experimental unit. Weed management Ohio State University, Columbus, OH; [email protected] treatments were applied the same day. Herbicides were tank-mixed with Hannah M. Mathers glyphosate (1 lb ae/A) using a CO2-pressurized backpack sprayer with Ohio State Univ-Hort & Crop Sci, Columbus, OH; [email protected] a 2-nozzle boom equipped with 8002 flat fan nozzles with an output Luke Case of 20 GPA and a pressure of 30 psi since weeds were present. Annual The Ohio State University, Columbus, OH; [email protected] weeds were removed by hand (perennials treated with glyphosate) prior Kyle Daniel to the application of the mulches. Soil volumetric water content and Ohio State University, Columbus, OH; [email protected] soil temperature at 4-inch depths were recorded hourly in each main plot. No supplemental water was provided. Weed control evaluations Weeds have been managed by manual weeding and/or herbicides for 5 weeks after treatment (WAT) indicated that all treatments provided many years by the nursery and landscape industry. Increasing labor satisfactory control (≥ 85%) of common lambsquarters, horseweed, costs by hand weeding and environmental impact due to the use and yellow foxtail. Glyphosate applied just prior to the application of chemicals have compelled scientists to look for alternate weed of wood chips or wheat straw did not provide the anticipated control control strategies. Herbicide treated mulch is one alternative which of Canada thistle or dandelion. Populations were variable, but more can be a potential environmental friendly approach to control weeds prevalent in these treatments. Spot applications with glyphosate re for a longer period of time, while reducing the weed control costs - and herbicides in the environment. The objective of this study was duced the Canada thistle population and eliminated the dandelions. to evaluate granular herbicides and mulch combinations at various Weed control evaluations were similar at 16 WAT except that the depths of mulching compared to liquid formulations of herbicides yellow foxtail control decreased in the chemical treatment. Soil water combined with mulches. An experiment was conducted at The Ohio content was greater within the wheat straw mulch treatment than other treatments and soil temperature was cooler until September when the State University, Columbus, Ohio with two types of mulches, hard- soil temperature within the chemical treatment began to reflect the wood and pine nuggets, at different depths (1, 2.5, and 5 inches) much cooler night temperatures. Soil water content was lowest and combined with two formulations of trifluralin +isoxaben [a liquid and soil temperature had the greatest daily fluctuation within the chemi a granular (Snapshot)] in a randomized complete block design. Two - separate experiments were replicated in time; one experiment was cal treatment. Soil temperature and soil water content differences did started in fall 2006 and repeated in fall 2007 and another experiment not affect vine growth (stem number and stem height) but may affect was started in spring 2007 and repeated in spring 2008. The Snapshot winter hardiness, bud break, fruit production, or fruit ripening. These was applied directly on the top of the mulch; the liquid formulation factors will be evaluated the next two years as well as weed control to was applied below or above the mulch or used to pretreat the mulch. determine if cultural weed management methods are feasible strategies There were total of 35 treatments including untreated control, mulch for grape production in North Dakota. alone without herbicide, and herbicide alone without mulch, and two commercially available mulches that came premixed with a herbicide. (107) An Online Cover Crop Decision Tool to Evaluations for weed control efficacy were done at 30, 60, 90, and Quickly Choose the Right Cover Crop 120 DAT for spring start experiments and 30, 180 and 210 DAT for Thomas Björkman* fall start experiments using visual ratings. Visual ratings were based Cornell University, Geneva, NY; [email protected] on a scale of 0 (no control) to 10 (complete control), with 7 and above commercially acceptable. Herbicide residue analysis was also done Joseph W. Shails using gas chromatography and high pressure liquid chromatography Cornell University, Geneva, NY; [email protected] techniques. One inch depth mulch either alone or in combination with Growers interested in using cover crops often miss opportunities to use herbicides in all the experiments did not show consistency in weed them because of small impediments to getting the right information. control. There were also no consistent differences between 2.5-inch Two important limitations were identified: selection appropriate crops depth mulch and 5.0-inch depth mulch alone or in combination with based on field constraints at the time of decision-making, and access herbicide. Pine nuggets had better weed control efficacy compared to to seed at competitive delivered cost. To overcome these limitations, Hardwood mulch. Soil analysis for herbicide residues revealed that we developed on online decision tool. The tool helps growers quickly mulches act as slow release carriers for herbicides for longer period choose cover crops based on when they can plant and their management of time compared to the herbicides applied alone treatments. goal. The results can then be narrowed easily by specific constraints

HORTSCIENCE, VOL. 44(4), JULY 2009 1099 due to rotation, equipment requirements and other factors. Once the provide practical strategies to facilitate healthful eating and physical selection is made, the tool provides concise and precise planting and activity through gardening. In addition to gardening at their school site, management instructions tailored to the location. The tool is a simple all children in garden clubs are furnished with plants to create a home search function on a PHP web page, tied to an easily-edited SQL da- garden. Complimentary curriculum experiences target the child’s proxy tabase on the server and a collection of HTML and PDF files with the self-efficacy, confidence in their ability to make requests to get parents instructions. An intentional limitation is the inclusion only of cover to act on their behalf such as daily “ride home” questions that prompt crops that are currently available at a reasonable cost (<$40 per acre parents with specific questions pertaining to their child’s garden club delivered for non-legumes in 2008). The precision that is essential to experiences. Once per week, the student indicates a physical activity making the tool useful requires limiting it’s application to a relatively they would like to participate in with their parent over the weekend. small region. However, it would be easy to adapt to regions where the Each club collectively sets a weekly goal to achieve one of four main requisite data are available about the cover crops. The tool is available objectives. Journal reflection and group discussion are used and at cover crop.net or tinyurl.com/NYccTool. Since its launch in April children are encouraged to involve parents in achieving these health 2008, it has delivered roughly 40 search results per day. goals. Parental education and support is additionally achieved through interaction with community members trained to act as role models for Marketing/Economics/Human Issues/ the children and parents at their site. This presentation describes the implementation of the parent component of this overweight and obesity International Horticulture prevention intervention. Saturday, 25 July 2009 1:15–2:00 pm Specified Source(s) of Funding: USDA NRI

(10) Fall After-school Garden Curriculum for (12) Consumer Purchasing Behavior and Preferences Overweight and Obesity Prevention for Locally Grown, Certified Organic Produce and Cynthia Domenghini* Value-added Products in the Mid-Atlantic Region Kansas State University, Manhattan, KS; [email protected] Amy Chamberlain* Candice Shoemaker Penn State University, State College, PA; [email protected] Kansas State University, Manhattan, KS; [email protected] Kathleen Kelley The Pennsylvania State University, University Park, PA; [email protected] According to current research, less than half of the children in the United States meet the recommendations for physical activity or fruit Jeffrey Hyde and vegetable consumption. The number of overweight and obese The Pennsylvania State University, University Park, PA; jeffhyde@psu. edu children is at an all-time high in the United States. Project PLANTS (Promoting Lifelong Activity and Nutrition Through Schools) is a two An Internet-based survey was administered (17 through 19 Nov. 2008) year research program testing the effects of after-school garden clubs for the purpose of studying purchasing behavior and preferences for lo- on sedentary behavior, physical activity and fruit and vegetable con- cally grown and certified organic produce and value-added products for sumption of fourth and fifth grade students for overweight and obesity consumers living in five metropolitan areas in the Mid-Atlantic region. prevention. The after-school garden club consists of a ten week fall Several aspects of purchasing behavior and preferences were examined, curriculum and a twelve week spring curriculum. The development and which included types of foods consumed, retail outlets from which implementation of the curriculum was based on the self-efficacy theory produce was primarily purchased, local and organic food purchasing addressing the target behaviors of eating healthy, being physically active behaviors, how produce was grown, branded and packaged, and what and reducing sedentary behavior. Each lesson includes a healthy snack, other external factors influenced consumer’s purchasing decisions. A physical activity and gardening. This presentation explains the design total of 1,565 consumers who reported that they made their household’s and application of the fall after-school garden club curriculum. food purchasing decisions participated in the 10-minute survey. Survey participants can be characterized as female (79.9%), Caucasian (82.9%), Specified Source(s) of Funding: USDA NRI under the age of 50 (51%), a member of a two-adult household (53.1%) (11) Affecting Family Support for Home Gardening with no children (64%), and having completed an associate level or technical degree or lower (60.6%) with an income of $75,000 or lower through an After-school Garden Club Intervention (62.2%). Analysis of the data was performed using Chi Square and Ann Marie Smith* ANOVA tests. Significant differences were observed between groups Kansas State University, Manhattan, KS; [email protected] in purchasing behaviors and product preferences (e.g. fresh produce Candice Shoemaker and processed products) across all examined demographics. Notable Kansas State University, Manhattan, KS; [email protected] trends in the data include differences in local and organic purchasing behavior, such as that consumers aged 65 and older significantly differed Promoting Lifelong Activity and Nutrition Through Schools from consumers aged 21–24 in reporting that purchasing locally-grown (projectPLANTS), is utilizing the Social Ecological Model and Social produce is more important than purchasing organic produce (ρ = .019). Cognitive Theory to promote gardening in fourth and fifth grade youth Other trends include where consumers preferred to shop for produce, and their families as a strategy for overweight and obesity prevention. such as that 56.3% of consumers from the Richmond metropolitan area Support from a child’s family environment is crucial since we aim to reported that they shopped primarily at discount stores (e.g. Walmart, have the child adopt these behaviors permanently. Parental behaviors for Super Target), compared to only 35.2% of consumers from the Philadel- starting and maintaining a home garden, decreasing sedentary behavior, phia metropolitan area. Results will assist produce industry members to and increasing fruit and vegetable consumption are targeted through determine what types of products should be offered to which consumer the psychosocial indicators self efficacy, knowledge, perceived social segments, and how to best market these products. support, and outcome expectancies, including perceived benefits and barriers, for each of the desired outcomes. Many methods of imple- Specified Source(s) of Funding: USDA Specialty Crop Research menting the home component have been built into the after-school Initiative gardening intervention. A biweekly parent newsletter is designed to

1100 HORTSCIENCE, VOL. 44(4), JULY 2009 (13) Invasive Plants in the Marketplace: Consumer needed by the project. Supportive public policies in Ohio help catalyze Perception and Purchasing Habits in New Jersey these investments. All of these resources come together in the “Cell to POSTERS–Saturday Sell” innovation pipeline. http://bioproducts.osu.edu/index.php/news- Brian Oleksak* room/108-what-is-cell-to-sell Rutgers/New Jersey Agricultural Experiment Station, Cooperative Exten- sion of Sussex County, Newton, NJ; [email protected] Specified Source(s) of Funding: Ohio Third Frontier - Department of Nicholas Polanin Development Rutgers/New Jersey Agricultural Experiment Station, Bridgewater, NJ; [email protected] (15) The Kenyan Export Horticulture Industry Joel Gehrig An intercept survey was conducted of New Jersey consumers to deter- University of Illinois, Urbana, IL; [email protected] mine their perception of invasive plants. Four hundred and twenty-one individuals participated in the survey which was conducted at locations John Masiunas* in northern and central New Jersey. The plants selected for consideration University of Illinois, Urbana, IL; [email protected] included species commonly offered in many local garden centers and Francis Itulya nurseries including species such as Japanese barberry (Berberis thun- Egerton University, Njoro; fi[email protected] bergii), Chinese silver grass (Miscanthus sinensis) and butterfly bush Vasey Mwaja (Buddleia davidii). These and other nursery plants are often used for Consultant, Nairobi; [email protected] their perceived resistance to deer damage in New Jersey landscapes. Horticulture is critical to Kenya’s food security and economy. The Proctored by the Rutgers/NJAES Master Gardener volunteers, the horticulture industry is the fastest growing agriculture sector growing survey participants were shown labeled photos of twelve plants and by 10% per year during the early 2000s. Exports of cut flowers, foliage, were asked to rate them as invasive, non-invasive or unsure. The survey tropical fruits and fresh vegetables, primarily to the United Kingdom participants were offered a definition of invasive based on the 2004 and other members of the European Union (EU), represent the second New Jersey Executive Order defining the term. The participants were most important source of foreign earnings (after tourism). Exports also surveyed to rate factors that influence their purchase of landscape include cut roses, pineapples, bananas, papayas, Asian vegetables, plants, which included price, quality, pest resistance, deer resistance, snow peas, and green beans. Trade with the EU has benefited from plant origin and invasiveness. Eighty-two percent of those surveyed lack of tariffs, increasing demand, and sufficient northbound air cargo rated English ivy (Hedera helix) as invasive, the highest response for but has required strict adherence to quality, labor, environmental, and all species in this survey; while purple loosestrife (Lythrum salicaria ) food safety standards. Export horticulture employs over two million was ranked second at 78%, despite widespread public awareness ini- Kenyans. The horticulture industry faces many challenges. The Cotonou tiatives regarding this invasive wetland species. However, the survey Agreement expired and negotiations for an Economic Partnership Agree- participants gave low assessments for troublesome forest invasive ment have been continuous especially over requirements for Kenya to species such as Norway maple (Acer platanoides); only 39% perceived provide duty-free access to its markets. Recent violence in Kenya has it to be invasive, while 52% responded that it is not invasive and 9% disrupted production and transportation. The EU demand has fallen were unsure. Similar responses were observed with burning bush with the global economic recession. Future depend is expected to slow (Euonymus alatus); 31% perceived it to be invasive, 59% believed it is as EU populations and incomes plateau. Kenya is facing stiff competi- not invasive and 10% were unsure. Similarly Russian olive (Elaeagnus tion in the EU market from the US, Israel, South Africa, Columbia, angustifolia), an aggresively spreading invasive on agricultural land in and Mexico. Large exporters and growers are replacing the traditional northern New Jersey was identified by only 34% of the respondents as smallholder operations that have supplied export markets. Single being invasive. Higher responses for invasive potential were observed women without benefits now dominate the labor force, raising ethical for species whose main mode of propagation is vegetative compared to issues. EUROPGAP requirements on traceability and process standards those species that spread primarily through seed dispersal mechanisms. are placing new burdens on exporters and causing further barriers to Results from the study have been useful in demonstrating consumer smallholder participation. There has been a trend toward increased recognition of invasive plants and how consumer demand and purchase processing, packing and product variety further limiting smallholder preferences can impact New Jersey’s forested and agricultural areas. opportunities. High fuel costs and European concern about food miles The findings from this survey allow Extension educators to target out - and global warming are challenging shipments via air cargo. Airfreight reach efforts by addressing the misperception consumers have about can account for >40% of the cost of Kenyan export horticulture crops. invasive species. These findings also begin to document the role home Will the Kenyan horticulture industry overcome these challenges and gardeners play in impacting the ecology well beyond their landscapes continue fostering economic growth? and neighborhoods. Specified Source(s) of Funding: University Specified Source(s) of Funding: Department, College, State and/or HATCH (16) USDA–CSREES–ISE Program Funded (14) Cell to Sell–Commercialization of BioProducts VEGINET–USA in Participation of International Kenneth B. Anderson* Conference on Horticulture (ICH-2009) Horticulture Ohio State University, Columbus, OH; [email protected] for Livelihood Security and Economic Growth Stephen Myers Usha Palaniswamy* Ohio State University, Columbus, OH; [email protected] Albany, NY; [email protected] “Cell to Sell” is a term that refers to OBIC’s market-pull model in Prem Nath which we connect a company’s bio-based innovation to industrial col- PNASF, Bangalore 560 094; [email protected] laborators across a product supply chain and research collaborators to The concept of VEGINET was introduced in 2002 to the delegates address technical gaps. Ohio has a strong industry network represented, from 37 countries who participated in the International Conference on in part, by our OBIC Board of advisors. Expertise across a large and Vegetables, Nov. 11–14, Bangalore India. The theme area on Technical growing list of research collaborators assures scientific support as Cooperation among Developing Countries (TCDC) presented a chal-

HORTSCIENCE, VOL. 44(4), JULY 2009 1101 lenge of lack of networking for this phenomenal knowledge and much [greenhouse mist propagation, 25 °C bottom heat, 0.3% IBA powder, more of it that is globally available and will be available in the future. perlite/ vermiculite 1:1 (v:v)]. Cuttings collected from 30 different wild A decision was made to collect, consolidate and easily retrieve and locations showed a significant location effect in rooting percentages. share for appropriate use by the stakeholders. Therefore, the General Among individual plants, rooting ranged from 0% to 100%, averaging Assembly of the Conference ICV-2002 decided to establish the Vegetable 51 ± 24%. Optimum cutting collection time is nearly all summer, and Science International Network (VEGINET). The goal of VEGINET is both plant variation and location influence final rooting success. to strengthen partnership and inter-institutional cooperation among the Specified Source(s) of Funding: USDA CSREES New Crop Opportuni- member organizations of the vegetable sector toward improved produc- ties Research Grant tion and utilization of vegetables. Through the funding received from USDA-CSREES-International Science Education Competitive Grants Program-2006, VEGINET-USA chapter was formed at approved March (264) Germination Responses of Purpletop and 2, 2007 by the VEGINET Secretariat at Prem Nath Agricultural Science Big Bluestem Caryopses Subjected to Prechilling, Foundation (PNASF), Bangalore, India. The VEGINET is co-sponsoring Sodium Hypochlorite, and Storage the upcoming International Conference on Horticulture (ICH-2009) to Michael W. Olszewski* be held during November 9-12, 2009 in Bangalore, Karnataka, India. Temple University, Ambler, PA; [email protected] The Conference is designed to provide a common forum for all stake Grant J. Folin holders to share their experience and expertise to suggest the technol- Temple University, Ambler, PA; [email protected] ogy-institution-policy package for sustainable production and market- ing of horticultural products. A special session on the TCDC has been Degraded meadow may be restored by sowing native seed mixes. scheduled at this conference for the VEGINET members to interact Establishment of native plants into an area may benefit the restoration with the international collaborators and stakeholders. process by increasing animal habitat in restored zones. Slow germina- tion and/or poor stand establishment following seeding of purpletop Specified Source(s) of Funding: USDA-CSREES-ISE (Tridens flavus) and big bluestem (Andropogon gerardii) may limit the use of these warm-season grasses native to the United States. Seed Technology/Asexual Propagation This study evaluated (1) caryopsis prechilling (presowing chilling) with distilled water (dH O); (2) prechilling with potassium nitrate Saturday, 25 July 2009 1:15–2:00 pm 2 (KNO3); (3) soaking in 10% chlorine bleach (v/v; 0.6% NaOCl); and (4) storage conditions following seed treatments. Prechilling of ‘VA (263) Propagation of Alaska Bog Blueberry, Ecotype’ purpletop and ‘Niagara, NY Ecotype’ big bluestem increased Vaccinium uliginosum final germination percentage (FGP) and germination rate, compared to nontreated caryopses (control), following 7 or 14 days at 5 °C in dH20 Patricia S. Holloway* or 0.2% KNO3 for purpletop and following 7 days at 5 °C in dH2O for University of Alaska Fairbanks, Fairbanks, AK; [email protected] big bluestem. Germination synchrony increased following prechilling Katie M. Kokx of purpletop but not for big bluestem. Determinations using slant tests University of Alaska Fairbanks, Fairbanks, AK; snowdog_ indicated that storing prechilled and dried-back purpletop caryopses [email protected] for 10 days at 5 °C reduced FGP and shoot lengths in comparison to James Auer moist-stored caryopses. Sowing prechilled, moist-nonstored purpletop University of Alaska Fairbanks, Fairbanks, AK; [email protected] caryopses resulted in greater FGP and shoot and root lengths than other Shannon Pearce seed treatment combinations or nontreated caryopses. Seedlings from University of Alaska Fairbanks, Fairbanks, AK; [email protected] prechilled caryopses of big bluestem moist-stored for 10 days at 21 °C had reduced root lengths in comparison to dried-back, stored caryopses. Fruits of bog blueberry, Vaccinium uliginosum, were collected in NaOCl treatments resulted in reduced FGP and root lengths for stored August and refrigerated for 8 days after which half were cleaned to purpletop but had little or no effect on big bluestem. Greenhouse tri- remove seeds and the remainder were frozen (–5 °C). Four replicates of als indicated stand establishment increased four weeks after sowing 50 fresh seeds were sown onto filter paper in Petri dishes as a control. prechilled caryopses compared to nontreated caryopses; however, Extracted seeds from fresh berries were air dried and sown as before sowing of prechilled or nontreated big bluestem caryopses resulted in at 2–3-day intervals up to two months to learn the effects of drying similar stand establishment. on seed germination. This experiment was repeated with seeds from frozen berries to learn the effects of freezing on seed germination. (265) Germination Response to Seed Seeds air dried at 21 °C for 60 days were cold stratified on moist filter paper at 4 °C for 30, 60, 90, and 120 days and compared to dry seeds Pretreatments in Two Genotypes of Mountain held at 4 °C and seeds extracted from frozen berries. Air-dried seeds Laurel (Kalmia latifolia L.) showed a linear decline in percent germination with the length of the Linda L. Taylor drying period, but all percentages did not exceed 35% during the 60- VPI & SU, Blacksburg, VA; [email protected] day period. Seeds from frozen berries maintained high germination Rumen Conev* percentages regardless of length of freezing time (70 ± 12%). Cold VPI & SU, Blacksburg, VA; [email protected] stratification improved germination (28.5% to 36.0%) over air-dried J. Roger Harris seeds (9.5 ± 1.9%), but there was no difference among stratification VPI & SU, Blacksburg, VA; [email protected] times. Germination of all stratified seeds was significantly lower than seed extracted from frozen berries (71.0 ± 10%). Optimum germination Mountain laurel, Kalmia latifolia, is an evergreen woody shrub in the occurs with seeds extracted from frozen berries and sown immediately family Ericaceae, and is found in the entire eastern portion of the United and not permitted to dry out. Softwood stem cuttings of wild-harvested States from southwestern Maine to northern Florida. Most mountain bog blueberry from new growth rooted more than 50% from 20 June laurel germplasm used for breeding purposes in the U.S. is from the through August, and rooting did not differ among collection dates northern portions of its range. Our research is directed toward breeding

1102 HORTSCIENCE, VOL. 44(4), JULY 2009 of mountain laurel germplasm better suited for the southern portion the National Plant Germplasm System and as such distributes these

of its range. The presented work investigates the differences in seed genetic resources for research and education purposes. POSTERS–Saturday germination of two mountain laurel genotypes—one originating from Specified Source(s) of Funding: USDA–ARS? a warmer location (USDA hardiness zone 8) and one originating from a colder location (USDA hardiness zone 6). Six hundred seeds of each genotype were subjected to 4 treatments—soaking overnight in distilled (267) Histological Analysis of Blueberry water (control), soaking overnight in 100 ppm gibberellic acid (GA), Regeneration soaking overnight in 200 ppm GA, and subjecting to scarification at Kate L. Thomas –80 °C for 24 hours with subsequent soaking overnight in distilled University of Delaware, Newark, DE; [email protected] water. Seeds were placed on moistened germination paper in Petri Thompson D. Pizzolato dishes and the Petri dishes placed randomly in a growth chamber (324 University of Delaware, Newark, DE; [email protected] µmol·m-2 s-1 of light from 8 a.m. to 12 a.m. at a constant temperature · Joanne M. Kramer of 21 °C and relative humidity of 80%). After 29 days the experiment University of Delaware, Newark, DE; [email protected] was discontinued as no further germination was occurring. All seeds subjected to scarification lost their vitality. An interaction between Conrad R. Pope seed origin and GA treatment was evident. The 100 ppm GA treatment University of Delaware, Newark, DE; [email protected] clearly inhibited germination in the southern genotype in terms of both James J. Polashock germination dynamics and rate. The same concentration applied to the USDA–ARS, Blueberry & Cranberry Res Lab, Chatsworth, NJ; james. northern genotype led to earlier germination and a higher germination [email protected] rate compared to the control. The 200 ppm GA treatment of the southern Sherry Kitto* genotype seeds did not have an effect on either onset of germination, or University of Delaware, Newark, DE; [email protected] on total germination compared to the untreated control. The northern Blueberry, Vaccinium corymbosum ‘Aurora’, was cultured in vitro genotype responded to the same treatment with earlier and accelerated on regeneration medium and histologically analyzed in an effort to germination, however, as of day 19, germination reached a plateau identify the regenerative cells. Leaves with petioles were cultured with insignificant increase afterwards. At the end of the experiment on Woody Plant Medium supplemented with TDZ and IAA with the the germination rate of the northern genotype treated with 200 ppm adaxial surface in contact with the medium and samples were removed GA was significantly lower than the control. daily and fixed to capture all stages of regeneration. Leaves were found to vary greatly in reaction time and intensity, as there was a gradient (266) Amending Storage Vessel and Media Improves of division from adaxial to abaxial and from proximal to distal ends Subculture Interval of Musa sp. Tissue Culture of the leaves. On three of the sectioned leaves, an area of organized Plantlets division made a mound formation which appeared meristematic. The spongy parenchyma were the first cells to begin formation of this area, Brian Irish* and are assumed to be the progenitors of regeneration. Further knowl- USDA–ARS TARS, Mayaguez, PR; [email protected] edge of blueberry regeneration not only helps to better understand the Ricardo Goenaga regeneration process, but could also prove useful in transformation USDA–ARS TARS, Mayaguez, PR; [email protected] studies of blueberry. Barbara Reed USDA–ARS, Corvallis, OR; [email protected] Specified Source(s) of Funding: NSF EPSCoR Grant No. EPS- 0447610 Bananas and plantains (Musa sp.) are some of the most important food crops in the world. The USDA–ARS, Tropical Agriculture Research (268) Nutrition Management of Perennial Stock Station Musa spp. collection consists of 140 accessions maintained as clonally propagated plants in field plots as well as in tissue culture. Plants to Optimize Cutting Quantity and Quality Accessions maintained in tissue culture require routine sub-culturing Holly L. Scoggins* as the nutrient medium is lost due to uptake by the plant. Current Virginia Tech, Blacksburg, VA; [email protected] subculture intervals are carried out, every six months which is a Jaime L. Crocker resource- and time-consuming effort. In an attempt to lengthen the Virginia Tech, Blacksburg, VA; [email protected] subculture interval period, an experiment was conducted to evaluate John R. Freeborn modified nutrient medium recipes as well as different storage vessels on Virginia Tech, Blacksburg, VA; [email protected] four Musa spp. accessions. Three containers were tested: 1) glass test ® Joel L. Shuman tubes, 2) glass test tubes + Parafilm and, 3) in tissue culture bags. In Virginia Tech, Blacksburg, VA; [email protected] addition, three medium formulations: 1) standard MS, 2) half-strength MS and, 3) MS with 4% mannitol were also evaluated. Treatment ef- Some popular garden perennials yield low numbers of viable cut- fects were determined by measuring root and leaf growth, number of tings per stock plant and/or produce cuttings that are slow to develop suckers and rating plant vigor. Glass test tubes + Parafilm® and culture significant root mass, preventing propagators from meeting demand bags resulted in increased transfer intervals regardless of variety and for rooted liners. Our objective was to determine the impacts of stock medium formulation. Accessions did not have a significant effect on plant nutrition on number of potential cuttings, rooting percentage, subculture interval. Subculture interval for glass test tubes + Parafilm® and the subsequent root development of cuttings of some popular but and tissue culture bags was extended an additional 6 months. Although difficult to propagate perennials. Gaura lindheimeri ‘Siskiyou Pink’, at the experiment’s termination the healthiest plants could be found in Dianthus ‘Pixie Star’, Perovskia atriplicifolia ‘Filigran’, and Salvia the half strength standard MS medium combined with the glass tubes ×sylvestris ‘May Night’, were evaluated using five treatments of 0, - + Parafilm®, additional advantages with the culture storage bags were 50, 100,150, 200, and 250 mg·L ¹ N. Greenhouse-grown stock plants identified, mainly the ease of using them for distribution purposes. The were fertilized with a custom-formulated complete liquid feed for ten USDA–ARS TARS is the official Musa spp. germplasm repository for weeks at which time potential cuttings were counted, and the sample

HORTSCIENCE, VOL. 44(4), JULY 2009 1103 cuttings were taken for rooting. Petiole sap nitrate was measured with at 44 days (74 days for CK) with 53.2% rooting rate (1.12% for CK). a specific ion meter (Cardy) to correlate real-time nitrogen status to Hormodin, straight IBA, NAA, and other yielded 3.9 to 22.6% rooting cutting yield and subsequent root growth. These measurements in rates. The quick-dip Dip’N Grow concentration should be 1:10 (1,000 turn were correlated with those obtained via capillary electrophoresis. mg·L-1 IBA + 500 mg·L-1 NAA) and higher or lower concentrations For the taxa studied, overall performance of stock plants and cuttings would significantly reduce the rooting ability of dabai rhodo. The including rooting percentage and root surface area and volume was quality of root, which measured by the total roots and the longest optimized with the 100 and 150 mg·L-1 N treatments. Little benefit was root length, followed the trend of the rooting rates. Cuttings treated obtained from the higher rates, but the 50 mg·L-1 N treatment produced with DipN Grow at 1:10 ratio produced 45 roots per cutting with the the lowest number of potential cuttings across all taxa. longest root of 8.1 cm. Rh. Decorum could be reproduced using semi- hardwood cuttings with heel, quickly dipping into the 1:10 Dip’N Specified Source(s) of Funding: The Fred C. Gloeckner Foundation, Inc. Grow for 5-10 seconds, and rooting with perlite and peat moss media. (269) Rapidly Screening Plant Species for Donglin Zhang is a guest professor at the Central South University of Forestry and Technology. Phytoremediation through Suspension Culture Guochen Yang* (271) Rooting and Acclimatization of Bunchberry North Carolina Agr & Tech State University, Greensboro, NC; yangg@ncat. In Vitro-Derived Propagules edu Hans J. Straight Zhongge (Cindy) Lu West Virginia University, Morgantown, WV; [email protected] North Carolina Agr & Tech State University, Greensboro, NC; zclu@ncat. edu Todd P. West* West Virginia University, Morgantown, WV; [email protected] Vestal Shirley North Carolina Agr & Tech State University, Greensboro, NC; yangg@ncat. This study evaluated the effects of nutrient salt formulations combined edu with auxin concentrations on subsequent in vitro adventitious root proliferation and the effects of different greenhouse propagation media Increasing interest in using phytoremediation to detoxify water and soil combined with ex vitro auxin concentrations for acclimatization of is producing demand for identifying approaches that can rapidly select bunchberry (Cornus canadensis L.). A factorial combination of nutri- plant species that will effectively capture and remove contaminants. ent salt formulations (MS, LP, and ½ Macro MS) ranging from high Plant suspension culture is a branch of plant tissue culture which is to low salt concentrations and auxin, indole-3-butryic acid potassium a special vegetative propagation method that satisfies this need. This salt (0, 5, 10 µM IBA), concentration were evaluated to determine a pilot study combined plant suspension culture and phytoremediation suitable medium for in vitro adventitious root proliferation. Stage II using guava and other plant tissues in a plant bioreactor to investigate multiplication propagules (callus-derived with average of 3 adventitious effectiveness of extracting and hyper-accumulating phosphorus. We shoots) were transferred to the in vitro rooting factorial treatments. observed a significant reduction of phosphorus on day 3 and by the end Rooting data was collected at 4 and 8 weeks after transfer to rooting of the third week an 80% reduction of phosphorus was recorded. We media treatments. There were no significant factorial combination with also observed that the pollutant aggregation process not only involve the respect to in vitro rooting. The presence of indole-3-butryic acid potas- plants’ root systems, but other tissues and organs too. This indicates that sium salt in the medium did have a significant effect on root number future development of plants for accumulation of elemental pollutants with 10 µM IBA having the highest success with adventitious root should focus not only on root systems, but other parts of the plant as proliferation as compared to 0 and 5 µM IBA. A factorial combination well. The findings also suggest that suspension culture may be a very of greenhouse propagation media (perlite, fine grade vermiculite, and effective way for rapidly screening plants that can be used to remove peatlite growing mix) and ex vitro rooting hormone concentrations undesired substances from soil and/or water systems. (100% Talc, 0.1, and 0.3% IBA) were evaluated to determine a suitable (270) Cutting Propagation of Wild Rhododendron ex vitro rooting and acclimatization protocol. Stage II multiplication decorum Franch. propagules, as previously described, were transferred to the ex vitro rooting/acclimatization factorial treatments. Propagules were places Xuejuan Chen in cell packs (37 mm2 × 65 mm) and were placed under intermittent Beijing Forestry University, Beijing; [email protected] mist (mist interval of 6 s every 6 min) within a glass-covered green- Yan Zhou house under natural photoperiod. Data was taken on survival and root Guizhou Academy of Science, Guiyang, Guizhou; [email protected] number 4 weeks after transfer to rooting/acclimatization treatments. Qixiang Zhang There were no significant factorial combination with respect to ex vitro Beijing Forestry University, Beijing; [email protected] adventitious root proliferation and plantlet survival based on acclima- Donglin Zhang* tization. Treatments affecting acclimatization survivability were not University of Maine, Orono, ME; [email protected] significantly different. The higher level of auxin, 0.3% was inhibitory to ex vitro root proliferation. There were no differences with respect to Xun Chen root proliferation with 100% talc and 0.1% IBA. Propagules growing Guizhou Academy of Science, Guiyang, Guizhou; chenxunk1956@163. com in fine grade vermiculite had significantly fewer adventitious roots as compared to perlite and peatlite media. In conclusion, bunchberry has Dabai rhodo (Rhododendron decorum Franch.) is one of dominant shown successful adventitious in vitro root proliferation with the ad- species in mountainous Guizhou, China, especially in the one-hundred dition of 10 µM IBA to the nutrient salt medium. Ex vitro adventitious miles of natural Rhododendron communities. To introduce this natural rooting and acclimatization were successful achieved with the use of treasure to our daily cultivation, two types of cuttings were collected perlite or peatlite greenhouse propagation medium and 100% talc or from its wild populations and treated with hormones. Semi-hardwood 0.1% IBA supplemented at time of transplanting. cuttings with heel produced roots while semi-hardwood cuttings without heel did not survive at all. Hormone type had significantly affected on Specified Source(s) of Funding: USDA–CSREES Formula Funded rooting of dabai rhodo. Dip’N Grow was better and to produce roots Hatch Project

1104 HORTSCIENCE, VOL. 44(4), JULY 2009 (272) Vegetative Propagation of Shepherdia explants were transferred to a fresh medium without kinetin or IBA and placed under the light treatments for six more months. We observed rotundifolia (Roundleaf Buffaloberry) from POSTERS–Saturday significant differences in the cultures grown under each light condition Softwood Cuttings including the amount of callus produced, color and texture of callus Chalita Sriladda* produced, and number of shoots produced. The red LED treatment had Utah State University, Logan, UT; [email protected] the fewest number of contaminated jars. Explants grown under the red Heidi Kratsch LEDs showed more base shoots per explant and higher fresh weight Utah State University, Logan, UT; [email protected] per explant. Our results suggest that in vitro plants grown under LEDS Billie Curtis with particular wavelengths of light may produce the desired growth Utah State University, Logan, UT; [email protected] in tissue culture without the need to add certain plant hormones to the culture medium. The use of LEDs, rather than fluorescent lamps Roger Kjelgren in micropropagation labs in Hawaii, could help reduce the cost of air Utah State University, Logan, UT; [email protected] conditioning the culture rooms and the need to frequently replace Native plant growers have been trying to introduce Shepherdia rotundi- fluorescent lamps to maintain sufficient light levels in cultures. folia for use in low-water urban landscapes. Limited seed availability, Specified Source(s) of Funding: Federal Floriculture Research Grant; difficulty with seed germination, and sensitivity to over-watering are problems that obstruct plant growers from success. The objective of Hatch this study was to evaluate strategies for propagation of S. rotundifolia (274) Evaluation of Four Grafting Methods from softwood cuttings. The experiment was arranged in a randomized strip-plot design with three treatment factors: inoculation at two levels for Propagating Cashew (Anacardium occidentale L.) (inoculated with native soil and non-inoculated), growing medium in the Dry Tropic of Mexico [calcined clay, peat-perlite (1 sphagnum peat : 1 perlite by vol.), and Juan-Manuel González-González an inorganic sand-gravel mix (2 sphagnum peat : 2 perlite : 1 calcined Universidad de Colima, Tecomán, Col.; [email protected] clay : 1 sand by vol.)], and rooting hormone [no hormone, 0.1%, and Salvador Guzmán-González* 0.3%- indole-3-butyric acid (IBA)]. In April 2008, stem bases of S. Universidad de Colima, Tecomán, Col.; [email protected] rotundifolia cuttings from plants growing in their natural habitats Oscar Iñiguez-Sánchez were wounded on two sides and moistened before dipping in growth Universidad de Colima, Tecomán, Col.; iñ[email protected] hormone. Cuttings were held on a propagation bench for 12 weeks under shade cloth and irrigated using intermittent mist. Mean PAR Cashew (Anacardium occidentale L.) is reproduced by seeds from level beneath the shade cloth was 203 µmol m-2 s-1. The interaction ‘Criollo’ cultivars in Mexico. The replication of desirable agronomic between inoculation and growing media was statistically significant in traits is difficult when selected plants are from sexual reproduction. mean root number (P < 0.0001) and mean total root length (P = 0.009). The heterogeneity of plants is observed as higher trees, irregular fresh Cuttings in calcined clay with no inoculation exhibited the greatest root- fruit yield, variable fruit quality, differential insect pest and disease ing percentage (72%), number of roots (mean 5 roots per cutting), and susceptibilities and lower number of plants per hectare, and extended total root length (mean 9 mm per cutting). The proportion of cuttings period for recovering the invest, and problems of commercialization producing callus was greatest (72%) when treated with 0.1% IBA. due to fruit quality and price. Vegetative propagation is an alternative Our data suggest that vegetative propagation of S. rotundifolia from for reducing the heterogeneity of cashew trees. Four grafting methods softwood cuttings is a viable alternative to seed propagation. Rooting for propagating cashew in the dry tropic of Colima, Mexico; splice percent can be increased by using calcined clay as a rooting medium side graft, cleft graft, whip graft and chip graft, were evaluated. The and treating wounded cuttings with 0.1% IBA. experiment was carried out in the Campus Tecomán of the Universidad de Colima. Rootstocks were from 8 months healthy plants with 1 m Specified Source(s) of Funding: Utah Agricultural Experiment Sta- height and 1 cm diameter, obtained from ‘Criollo’ seedlings, and the tion scions was obtained from a healthy 10-year-old ‘Amarillo’ cultivar (273) Use of Light-Emitting Diodes in Dracaena donator tree. This donator was selected for its excellent agronomic traits and fruit yield. Vigorous and terminal scions were used; these Micropropagation were disinfected with fungicide and used the same day of excision. Kent D. Kobayashi* The experiment was distributed under a completely randomized design. University of Hawaii at Manoa, Honolulu, HI; [email protected] Splice side graft had 33.3 % (5 grafts) of success 60 days after grafting, John Griffis Other types of graft (cleft graft, whip graft and chip graft) were kept Honolulu, HI; [email protected] latent for 10 days, the scions and rootstocks initiated to losing energy and to not reestablishing the vascular bundles, were dehydrated and Light quality influences the growth and morphology of plant tissues and dried progressively during 60 days after grafting. plant development. Light-emitting diodes (LEDs) offer precise control of spectral composition and light quality, resulting in monochromatic Specified Source(s) of Funding: Universidad de Colima lighting. A comparison of plantlet growth under LEDs and white fluo- rescent lamps was conducted by placing in vitro cultures of Dracaena (275) In Vitro Regeneration of Blueberry (Vaccinium ‘Lisa’ under red LEDs, blue LEDs, and white fluorescent lamps. The corymbosum L.) ‘Biloxi’ in Culture Media with N6- objective of this study was to determine the effects of red LEDs and (2-isopentil) Adenina blue LEDs on the growth of Dracaena plantlets. Explants consisting Salvador Guzmán-González* of 2.5-cm stem segments of Dracaena ‘Lisa’ were placed in a modi- fied MS (Murashige & Skoog) medium supplemented with 3.0 mg·L-1 Universidad de Colima, Tecomán, Col.; [email protected] kinetin, 0.2 mg·L-1 IBA, adenine sulfate, sodium phosphate, inositol, Pedro Valadez-Ramírez and sucrose. The pH was 5.6. Jars containing one explant each were Universidad de Colima, Tecomán, Col.; [email protected] placed under red LEDs, blue LEDs, and white fluorescent lamps at a Juan-Manuel González-González light level of 75 µmol·m2·s and a 12-h photoperiod. After five months, Universidad de Colima, Tecomán, Col.; [email protected]

HORTSCIENCE, VOL. 44(4), JULY 2009 1105 Gilberto Manzo-Sánchez cular bundles were not re-established and initiated to be dehydrating Universidad de Colima, Tecomán, Col.; [email protected] and later they dried off. Elpidio Peña-Beltrán Specified Source(s) of Funding: Universidad de Colima Universidad de Colima, Tecomán, Col.; [email protected] Blueberry (Vaccinium corymbosum L.) is a plant fruit with special nutritious properties demanded in several countries around the world. The aim of this study was to evaluate the in vitro regeneration and Horticultural Crops Culture and Management: growth of shoots of blueberry ‘Biloxi’ in culture media with different Fruit and Nut Crops concentrations of N6-(2-isopentil) adenina (2iP). The establishment phase consisted of the culture of 1.5 cm-long internodal segments on Sunday, 26 July 2009 12:00–12:45 pm Woody Plant Medium (WPM) supplemented with 0, 0.1, 0.32, 1.0, 3.16 y 10.0 µM of 2iP, and amended with 20 g/L of sucrose and 2.5 g/L of (216) Fruit Growth and Quality as Influenced by phytagel, and pH 5.2. Culture vessels were incubated in a chamber Low Irradiance Levels in the Pear Cultivar growth at 25 °C during three weeks with a 16-h light/8-h darkness photoperiod. After in vitro shoots with a size of 2-3 cm were transferred Red Sensation to rooting medium consisting of WPM supplemented with 0, 2, 4, 6, Patricia I. Garriz* 8, and 10 µM of indole-3-acetic acid (AIA). Results showed that there Faculty of Agriculture, Comahue National University, Argentina, 8303 was not a significant difference among the treatments of 2iP according Cinco Saltos, RN; [email protected] to the shoot percentage and internodal distance variables, whose values Graciela M. Colavita oscillated from 80% to 98% and 0.4 to 0.5 cm, respectively. On the Faculty of Agriculture, Comahue National University, Argentina, 8303 other hand, in media with 1, 3 and 10 µM of 2iP it was registered the Cinco Saltos, RN; [email protected] highest shoot length and number of leaves, ranging from 2.6 to 2.8 cm Hugo L. Alvarez and 6 and 7 leaves, respectively. Percentage of rooting and number of Faculty of Agriculture, Comahue National University, Argentina, 8303 roots per shoot after six weeks were highest in shoots transferred to Cinco Saltos, RN; [email protected] medium WPM supplemented with 8 and 10 µM of AIA, whose values Valeria Blackhall were 54% and 61% and 2 and 3 roots, respectively We conclude that Faculty of Agriculture, Comahue National University, Argentina, 8303 multiplication phase of blueberry var. Biloxi is successfully achieved Cinco Saltos, RN; [email protected] by the culture of internodal segments in media with 1 to 10 µM of 2iP. Shading frequently occurs in the interior of pear tree canopies. There- This protocol provides to our knowledge the first effort to develop an fore, it has become increasingly important to study the effects low efficient strategy for the mass propagation of this blueberry variety. irradiance on final yield. This work was undertaken to measure the Specified Source(s) of Funding: Universidad de Colima influence of light reduction on ‘Red Sensation’ pear fruit growth and quality in the environmental conditions of the High Valley region, Río (276) Jack Fruit (Artocarpus heterophyllus Lam.) Negro, Argentina, during the 2007–08 growing season. Fifteen-year- Propagation Testing Three Types of Bud Graft old trees grafted on Pyrus communis L. rootstock, planted in a single Juan-Manuel González-González row from north to south with spacing of 2.3 m × 4.0 m and trained to Universidad de Colima, Tecomán, Col.; [email protected] palmette leader were used. The orchard was fertilised and sprayed for pest and disease control according to the local standard programme. Salvador Guzmán-González* The experimental site was located in an arid region, with average an- Universidad de Colima, Tecomán, Col.; [email protected] nual rainfall of 250 mm. An automated meteorological station, situated Alejandro Pérez-Amezcua close to the experimental orchard at the Comahue National University Universidad de Colima, Tecomán, Col.; [email protected] (38°56’S, 67°59’W), continuously monitored high, mean and low air The Jack fruit trees produced by seeds, are usually more precocious temperature, air relative humidity and solar radiation. Full bloom oc- than the majority of other fruit-bearing species, nevertheless, this spread curred on 30 September 2007. Treatments were: a) application of shade, generates variability in size and forms of the trees. The grafted trees by cloth-covering individual whole branches with an 80% saran shade can begin to produce fruits in the third year. The spread by means of cloth, from 19 to 113 days after full bloom (DAFB) and b) control. graft is very important, since the utilization of plants grafted on the Analysis of variance was used to evaluate the effect of shade on fruit establishment of new gardens, it allows homogeneous and to raise growth and maturity indices; mean separations were computed with the yields of the plants; as well as the resistance to diseases, plagues Student’s t-test and equations were developed with SYSTAT procedure. and to the preservation of improved varieties or native types. The aim From 19 October to 16 November 2007, fruit diameter was measured of this experiment was to evaluate the efficiency of three methods of at two-day intervals. Lineal models best fit fruit growth and significant bud graft for the asexual spread of plants of jack fruit. Methods of differences (P ≤ 0.05) were found between shaded and sun-exposed bud graft: “T”, patch and splinter were evaluated. The experiment was treatments: FD = 0.5024 DAFB + 0.8630, R2 = 0.82 and FD = 0.6255 developed in Colima’s University, campus Tecomán, with a tropical DAFB – 1.7188, R2 = 0.83, respectively. At commercial harvest, light very hot climate, (BS1) and to 33 meters on the level of the sea. The reduction decreased fruit diameter by 14.7 % and fruit weight by 35.8 rootstocks were ‘Criollo’, of seven months of age. The donating trees %, as compared to the control; it also affected fruit color, firmness and of vegetative material are located in the same zone, they were selected soluble solids concentration: 40.0 vs. 81.1 %, 22.8 vs. 21.4 N and 8.93 by your good fytosanitary condition, productivity and good size of vs. 12.0 °Brix for treatments a) and b), respectively. It was concluded that fruit, in full production. Sub terminals scions were used, defoliated shading reduced ‘Red Sensation’ pear quality and diminished fruit size. and disinfected with fungicide and were grafted the same day of your These results suggest some goals of pruning and training for optimizing cut. The experimental design was completely at random The results yield, by efficiently converting captured sunlight into fruit. indicate that the best type of graft after 60 days was that of patch with Specified Source(s) of Funding: Grant from Comahue National Uni- 35 % (seven plants) of grafts successfully. Other treatments answered versity, Argentina with very much vigor, but after 26 days of remaining latent, the vas-

1106 HORTSCIENCE, VOL. 44(4), JULY 2009 (217) Rootstocks for California Prune primary reason for mortality was likely due to record rains in 2007 (Prunus domestica) Production coupled with the longer moisture retention from deeper mulch. Richard P. Buchner* Specified Source(s) of Funding: Hatch University of California, Red Bluff, CA; [email protected] (219) Diurnal Variation of Photosynthetic Growing prune trees from seed does not produce a tree genetically Characteristics in Coolidge Pineapple Guava identical to its parent. Prune seeds are derived from open pollinated flowers so seeds are progeny of parent trees and are not genetically Xu Zhou identical. In fruit and nut production, the industry needs every tree Central South University of Forestry and Technology, Changsha; csuft- producing the same variety. Clonal propagation of fruitwood is one [email protected] option. However it is much more common to graft the desired variety Shengping Xiang on a rootstock of choice. This allows a clonal choice for the prune Central South University of Forestry and Technology, Changsha; csuft- variety and a rootstock choice to manage orchard site problems such [email protected] as soil type and structure, nematodes and/or diseases. Because prune Deyi Yuan* orchard life may be 25 to 40 years, it is important to anticipate root- Central South University of Forestry and Technology, Changsha; yuan- stock responses to the soil type where it will be planted and different [email protected] POSTERS–Sunday soil-borne diseases and pests which may be present. Certain rootstocks Sidong Zhao respond differently than others to soil, disease, and pest problems; Central South University of Forestry and Technology, Changsha; csuft- selection of the most suitable stock for the proposed site can have a [email protected] major influence on long-term performance of an orchard. Similarly, Donglin Zhang with spot or localized replanting, causes of original tree loss should be University of Maine, Orono, ME; [email protected] taken into account in selecting replacement stocks. The plum rootstocks, Lin Zhang Myrobalan (Prunus cerasifera), Myrobalan 29C (Prunus cerasifera Central South University of Forestry and Technology, Huann 410004; cuttings), Mariana 2624 (Prunus cerasifera × Prunus munsoniana) are [email protected] most commonly used in California prune orchards. Other Prunus spe- Feijoa sellowiana cies such as peach, almond and apricot are rootstocks used for special The pineapple guava ( Berg.), a great commercial situations. The M40 Marianna plum stock is a relatively new release plant for its fruit quality and unique flavor, has been introduced into China in recent years. To better grow this plant for orchard, the diurnal that may in time replace Mariana 2624. Advantages/disadvantages for variations of photosynthesis on Feijoa sellowiana ‘Coolidge’ were each rootstock are discussed. studied using a Li-6400 portable photosynthesis system. Relationships Specified Source(s) of Funding: UC Cooperative Extension between net photosynthetic rate (Pn) and its physio-ecological factors, including photosynthetic active radiation (PAR), relative humidity of

(218) Pecan Shell Mulch Affects Peach Tree Growth, the air (RH), temperature of leaves (Tl), atmospheric CO2 concentration (Ca), stomatal conductance (Cond), intercellar CO concentration (Ci), Yield, and Survival 2 and transpiration rate (Tr) etc. were determined by path analysis and Eric Stafne* stepwise regression equation. The curve of diurnal variation of Pn was Oklahoma State University, Stillwater, OK; [email protected] demonstrated two peaks in a clear day, which appeared at 12:00 and 14:00, Becky Carroll respectively. There was a clear depression at noon. Correlation analysis Oklahoma State University, Stillwater, OK; [email protected] showed that there were positive relationship between Pn with Cond Charles Rohla and Tr. Their correlation equations were Pn = 6.1883 Cond2+66.0030 The Samuel Roberts Noble Foundation, Ardmore, OK; [email protected] Cond-0.6763, (R2 = 0.893) and Pn = 0.5473 Tr3-5.9285 Tr2+22.1925 Tr-18.042, (R2 Pecan shells are a waste product that are occasionally used for mulch = 0.914), respectively. Among the ecological factors, PAR was the major one that influenced the variations of Pn. Cond and in ornamental landscape settings; yet most shell waste is left in piles Tr were two key physiological factors that influenced the variations of near the shelling facility or discarded by other methods. If another Pn. The correlation equation between Pn and the major physio-ecologi use for this waste product could be developed, it may lead to added - cal factors was Pn = 73.82-0.0041 PAR+1.8069 RH+1.9585 Tl-0.4479 income for pecan producers. A peach orchard was planted at a spac- Ca-102.62 Cond+3.6657 Tr-0.1354 Ci (R2 ing of 5.5 m × 6.8 m in Feb. 2005 at the Cimarron Valley Research = 0.999). This study can Station in Perkins, Okla. consisting of several different cultivars on provide foundational data on the physiological ecology in pineapple ‘Halford’ rootstock. From this orchard, the ‘Loring’ block was chosen guava for its introduction, cultivation and production. to determine what effect pecan mulch would have on peach trees. Five Specified Source(s) of Funding: “948 Project” of National Forestry treatments were imposed: no herbicide, no mulch, mow only (Trt 1), Bureau (2008-4-06) herbicide (glyphosate) (Trt 2), 1.8 m × 1.8 m × 5 cm deep mulch (Trt 3), 1.8 m × 1.8 m × 10 cm deep mulch (Trt 4), and 1.8 m × 1.8 m × (220) Growth and Development of Huafeng Pear 15 cm deep mulch (Trt 5). All blooms and fruit were eliminated by Deyi Yuan* frosts or freezes in 2006 and 2007. Yields in 2008 revealed that Trt 1 Central South University of Forestry and Technology, Changsha; yuan- was statistically the poorest option (13.2 kg/tree and 93 fruit/tree). All [email protected] other treatments did not differ, but Trt 4 had the highest mean yield Jinghua Duan (26.4 kg/tree and 195 fruit/tree). Fruit quality (°Brix) and fruit weight Non-timber Forestry Research and Development Center, Chinese Acad- did not differ by treatment. Tree growth parameters of tree height, emy of Forestry, Zhengzhou; [email protected] pruning weights, and trunk caliper were not statistically different Donglin Zhang with the exception of Trt 1 which was significantly less in all three University of Maine, Orono, ME; [email protected] categories beginning in 2007. Tree mortality increased with depth of Xiaofeng Tan pecan mulch. Treatments 1–3 had little tree loss (0–5%), whereas Trt Central South University of Forestry and Technology, Hunan 410004; 4 and Trt 5 had increased mortality (15% and 35%, respectively). The [email protected]

HORTSCIENCE, VOL. 44(4), JULY 2009 1107 Lin Zhang in order to increase fruit size. Central South University of Forestry and Technology, Huann 410004; [email protected] Specified Source(s) of Funding: Evans-Allen Pyrus pyrifolia Nakai. ‘Huafeng’ is a new superior pear cultivar derived (222) Improving ‘Bing’ Sweet Cherry Fruit Quality from the cross of ‘Niitaka’ × ‘Hosui’. To investigate the growth and with Plant Growth Regulators development of huafeng pear, we measured stem circumference and Caixi Zhang* branch length and analyzed leaf and fruit nutrients. Huafeng pear grew Washington State University, Prosser, WA; [email protected] fast at its first 1–3 years with vigorous branches. The stem circumfer- ence increased 142% at the first three year, which was higher than its Matthew Whiting stem growth at 120% from 4-6 years. The one-year fruit branches grew Washington State University, Prosser, WA; [email protected] well with high percentage of flower buds (average at 63.2%) and their Final fruit diameter is the prime determinant of sweet cherry value. fruiting capacity was similar to that of the two and three-year’s fruit Previous research has shown that mesocarp cell size accounts for most branches. In 30 to 150 days after blossom, SPAD increased gradually variability in fruit size within a genotype. Our research program is now from 39.6 to 48.8. The contents of P, K and Mg in leaves decreased evaluating the potential to improve sweet cherry fruit size/weight with gradually from 0.058% to 0.124%, 1.07% to 1.48%, 0.250% to 0.332%, growth regulators. In the current study we screened 8 plant growth respectively. Both Ca and N content increased from 1.10% to 2.37% regulators and their combinations for their ability to increase ‘Bing’ and 2.08% to 2.85%. The increment of fruit size showed a ‘W’ shape, fruit weight. Each treatment was applied in lanolin paste directly to fruit a trend of “fast-slow-fast-slow-fast.” The increase of water content in pedicels at 9 and 30 days after full bloom, to coincide with estimated fruit was similar to the change of fruit size, i.e. water content was higher peak in cell division and onset of cell expansion activity, respectively. when the fruit size increased faster. Inorganic matters changed fast in During the cell division stage, several cytokinins improved fruit weight early fruit stage. The K content showed a highest change from the period significantly (ca. + 15%) with N-(2-Chloro-4-pyridyl)-N’-phenylurea of young fruits (1.092g×100g-1 FW) to mature fruits (1.035g×100g-1 (CPPU) at 100 mg·L-1 being the best. Auxin treatments were ineffective FW). Fruit sugar content exhibited progressive accumulation and its at improving fruit quality but several GA treatments improved fruit -1 highest content was 9.83 g×100g-1 FW in mature fruits. Organic acid size significantly. GA3 at 200 mg·L during the cell division stage was displayed a trend of “decline-rise-decline” pattern and the lowest level the most effective and improved final fruit weight by 15%. From this was at the mature fruit. Therefore, growers should harvest huafeng pear treatment, 60% of the fruit were ≥ 9 g compared to just 15% of similar within 150 to 160 days after blossom. weight fruit from untreated limbs. These results are consistent with the previous study of applications at full bloom and show promise for early Specified Source(s) of Funding: the agricultural achievement transform- applications of GA to improve sweet cherry fruit quality. Furthermore, ing programs of science and technology department (2008GB2D200219) 3 while single applications of GA or CPPU during fruit expansion did and Scientific Research Fund of Central South University of Forestry 1 not increase fruit weight, their combination increased fruit weight by & Technology (2008007B). 19%. More than 80% fruit fall into the category of ≥ 9 g. Results of (221) Utilizing Within-cluster Hand-thinning to large-scale orchard trials will also be discussed. Increase Pawpaw Fruit Weight Specified Source(s) of Funding: Washington Tree Fruit Research Com- Sheri Crabtree* mission, WSU ARC Kentucky State University, Frankfort, KY; [email protected] (223) Influence of Proline Foliar Application on the Kirk Pomper Kentucky State University, Frankfort, KY; [email protected] Growth Characteristic and Fruit Quality of ‘Fuji’ Jeremiah Lowe Apple Trees Kentucky State University, Frankfort, KY; [email protected] Ik-Jo Chun* Andong National University, Andong; [email protected] Pawpaw (Asimina triloba) is a tree fruit native to the Eastern U.S. with increasing popularity as a high-value niche crop. Pawpaw fruit sell for Byeong-Gak Kim $3–4/lb at farmers markets and $5–10/lb via mail order. Two undesir- Andong National University, Andong; [email protected] able characteristics of pawpaw are great variation in fruit size and short In-Kyu Kang shelf life, caused in part by a small tear in the skin created when fruit Kyungpook National University, Sangju; [email protected] are harvested from the cluster, allowing pathogens to enter the fruit. Frost damages often occur in several apple tree growing areas. Apple It is beneficial for growers to produce large, consistently sized fruit to growers have been used many active ways to protect apple trees against command a premium price and decrease time sorting fruit. Within-cluster frost damage, such as combustor, air moving fan, and overhead sprinkler. thinning of pawpaw to one fruit could increase fruit size and improve However, there is little information available for chemical protectants in shelf-life by allowing the peduncle to be cut at harvest, maintaining an apple trees, except plant growth regulators. This study was carried out intact epidermis. Four pawpaw cultivars (Mitchell, NC-1, Overleese, to find the effects of four different concentrations of proline applications and PA-Golden) were utilized in a fruit thinning study at the Kentucky on the frost resistance and growth characteristics of young and mature State University research farm over two years. The objective of the ‘Fuji’ apple trees, which were one and eleven-year-old, respectively. study was to determine the effect of hand-thinning on pawpaw fruit The application of 50 mg·L-1 proline significantly increased leaf fresh size. Treatments were no thinning (control) or hand-thinning all clusters weight and leaf dry weight of young ‘Fuji’ apple trees, compared with on the tree to one fruit per cluster. Trees were thinned in early June, those on the control. In addition, foliar spray of 50 mg·L-1 proline sig- when fruit were approximately 1.5 cm in length. Fruit were harvested nificantly promotes flower formation in young ‘Fuji’ apple trees. In the from mid August through late September, and twenty-five fruit per tree growth characteristics of mature ‘Fuji’ apple trees, the current shoot were weighed to obtain average fruit weights. Fruit from hand-thinned growth were relatively shorter in the 25 or 100 mg·L-1 of proline treat- trees weighed significantly more than those from control trees (47% ments than those on control tree. However, there were no differences and 23% greater weight in 2006 and 2008, respectively). Pawpaw, like in tree height, truck cross-sectional area, and chlorophyll content in many other tree fruits, benefits from fruit thinning to reduce crop load the leaves of both young and mature ‘Fuji’ apple trees. Among the fruit

1108 HORTSCIENCE, VOL. 44(4), JULY 2009 qualities of ‘Fuji’ trees, the fruits treated with 10 or 100 mg·L-1 proline indicated that ‘FHIA-18’ and ‘FHIA-03’ showed excellent bunch and increased 18% or 22% of fruit fresh weights, respectively. Fruit color, finger characteristics but highly susceptible to finger drop. In contrast, firmness, and soluble solids concentration were not affected by proline ‘SH 3640’ had an average bunch and fingers characteristics but had the foliar applications in ‘Fuji’ apple trees. Double applications of 50 and highest TSS:acid ratio. Among all studied cultivars, ‘SH 3436-9’ was 100 mg·L-1 proline improved the formation of fruitlets in terminal and similar to ‘Williams’ variety in bunch weight, overall yield and fruit axillary blossom in mature ‘Fuji’ apple trees after two frost damages characteristics. Based on yield and postharvest quality attributes, the occurred in the blooming season in 2008. cultivation of ‘FHIA-18’, ‘FHIA-03’, and ‘FHIA-21’ banana cultivars is recommended under the growing conditions of Oman. Specified Source(s) of Funding: myself (226) Automation for Specialty Crops: (224) Dormant-applied Nitrogen Fertilizers Advance A Comprehensive Strategy, Current Results, ‘French’ Prune Bloom and Future Goals Franz Niederholzer* UC Cooperative Extension, Yuba City, CA; [email protected] Sanjiv Singh Carnegie Mellon University, Pittsburgh, PA; [email protected] Manipulating deciduous fruit tree bloom timing in temperate climates Tara Baugher POSTERS–Sunday can spread the risk of crop loss from extreme temperatures. Heavy Penn State University, Gettysburg, PA; [email protected] rates of horticultural oil (4% to 5% v/v in 100 gallon/acre = 935 L/ha) applied in the dormant season can advance bloom in prune orchards Marcel Bergerman in California. Risk of phytotoxicity limits this practice. Calcium am- Carnegie Mellon University, Pittsburgh, PA; [email protected] monium nitrate (CAN17) fertilizer (25% v/v) plus non-ionic surfactant Ben Grocholsky (NIS) at 2% v/v as a canopy spray in mid-winter (30-60 chill portions) Carnegie Mellon University, Pittsburgh, PA; [email protected] can advance prune bloom in the Sacramento Valley of California. Use Jay Harper of a nitrogen (N) fertilizer spray to break rest and advance bloom may Penn State University, University Park, PA; [email protected] be a viable alternative to horticultural oil for California prune grow- Gwen-Alyn Hoheisel ers. A field trial was established to compare the established CAN17 Washington State University, Prosser, WA; [email protected] rate to two other commercially available N fertilizer materials – dry Larry Hull potassium nitrate (KN) and a 28–0–0 urea-triazone solution (UTS). The Penn State University, Biglerville, PA; [email protected] KN and UTS treatments were applied at 5% w/w and a 1% v/v rates, Vincent Jones respectively. The three N fertilizer treatments, each applied with 2% Washington State University, Wenatchee, WA; [email protected] NIS, were established in a randomized complete block design (n = 4) in January, 2008 and January 2009 in commercial orchards near Marysville, George Kantor California. Additional treatments included horticultural oil (4% v/v) Carnegie Mellon University, Pittsburgh, PA; [email protected] and an untreated control. All sprays were applied between 50 and 54 Harvey Koselka accumulated Chill Portions. Treatments were applied to individual Vision Robotics, San Diego, CA; [email protected] trees by backpack mistblower at a spray volume per tree equivalent Karen Lewis to 100 gpa (935 l/ha). Separate orchards under similar management Washington State University, Ephrata, WA; [email protected] were used in 2008 and 2009. Three small branches (< 2 cm diameter) William Messner equally spaced around each tree and containing 40–100 flowers each Carnegie Mellon University, Pittsburgh, PA; [email protected] were flagged prior to bloom. Open flowers were counted every 2–3 Henry Ngugi days through bloom. In 2008, all rest breaking treatments advanced Penn State University, Biglerville, PA; [email protected] time of 50% full bloom by 5–6 days over the untreated control. 2009 data will be presented. James Owen* Oregon State University, Aurora, OR; [email protected] Specified Source(s) of Funding: California Dried Plum Board Johnny Park (225) Production and Fruit Quality Attributes of Purdue University, West Lafayette, IN; [email protected] Clark Seavert Eight Exotic Banana Genotypes Grown in Oman Oregon State University, Aurora, OR; [email protected] Rashid Al-Yahyai* Sultan Qaboos University, Al-Khod 123; [email protected] Specialty crops constitute a $45 billion/year industry that is steadily growing. As opposed to broadland crops (such as wheat and soybean), Abdullah Al-Hosni they are characterized by the need for intensive cultivation. This requires Ministry of Agriculture, Directorate General of Agriculture and Livestock a skilled, efficient, cost-effective labor force. This diminishing labor Research, Seeb 121; [email protected] force is limiting economic returns and adversely affecting the cost of Banana is an important fruit crop commonly cultivated in Oman, a production resulting in a labor crisis. In addition, an increasing con- semi-arid country in the Arabian Peninsula. Due to emergence of ba- sumer demand for a safe, affordable, traceable, and high quality food nana diseases in neighboring production regions, several exotic banana supply and the need to minimize the environmental footprint represent genotypes have been introduced to Oman for evaluation. In this study, key challenges for specialty crop sustainability in the United States. seven cultivars that included ‘SH 3436-9’, ‘FHIA-21’, ‘FHIA-03’, Recently, our team started a 4-year effort to develop a comprehensive ‘FHIA-18’, ‘SH 3640’, ‘FHIA-25’, and ‘FHIA-23’ were evaluated automation strategy for tree fruit production. Our approach is based and compared with the locally grown ‘Williams’ cultivar for yield on a triad that spans the entire production spectrum from nursery and fruit quality characteristics. Results from this study showed that production to fruit harvest that includes: (1) Information, mobility, ‘FHIA-25’ had the greatest bunch weight, number of hands and number and manipulation technologies (reconfigurable mobility, positioning, of fingers followed by ‘FHIA-18’. The introduced genotypes showed information management, and augmented fruit harvesting). Reconfigu- great variations in the measured postharvest characteristics. The results rable mobility creates low-cost, robust moving platforms that can be

HORTSCIENCE, VOL. 44(4), JULY 2009 1109 tasked based on specific needs of the growers. Accurate positioning If the California black ripe table olive processing industry is to sur- provides the capability of georeferencing specific observations even vive it must develop mechanical harvesters capable of efficiently and when GPS is unavailable. Information management deals with the economically harvesting the unripe Olea europaea cv. Manzanillo that multi-scale, spatio-temporal data that must be integrated into a com- is oxidized in processing to become the crisp California “black ripe” mon geographic information system. Finally, assisted harvest focuses table olive. These harvesters should be capable harvesting at least one on increasing efficiency of fruit picking and reducing fruit damage in acre per hour with a final fruit removal efficiency of 80%, produce fruit the field. (2) Plant science technologies (plant stress and disease detec- capable of being processed into commercially competitive product, and tion, monitoring insect populations and infestations, automated caliper not cost more U.S. $100.00 per short ton to operate. Weight is important measurement, and autonomous crop load scouting). Biotic stress such as table olive orchards are irrigated immediately prior to harvest. Size is as pest damage account for 10–30% of yield losses while abiotic stress, a concern as most orchards have row widths of no more than 7-m trunk such as nutrient and poor water management, account for 70–90% of to trunk and 4.5-m canopy widths. In 2008 a canopy contact picking the yield reductions. Agricultural progress has primarily identified fac- head harvester, a trunk shaker, and over the row straddle harvester with tors that limit productivity and provide either genetic improvement or dual canopy contact heads, were evaluated in commercial ‘Manzanillo’ cultural strategies to mitigate the stresses. We focus on tools to detect orchards. The canopy contact harvester produced a significantly lower, plant stress and crop load and integrate this information into manage- 88.0%*** canning percentage, and adjusted value per ton, $1013.80***, ment techniques that will increase productivity and quality of the final for mechanically harvested fruit, versus 96.2% and $1137.80 per ton for product. (3) Outreach and commercialization. Research shows that it hand harvested olives. However, these canning percentages and values takes roughly eight years for new technology to be incorporated by per ton are well within normal ranges. This indicates this canopy head early adopters, and as long as 15 years for full industry adoption. We can produce commercially acceptable fruit. The harvester averaged intend to reduce this amount of time significantly by: (a) proactively 57.8% final fruit removal efficiency. This prototype is also too slow, fielding the technologies developed in real apple orchards and tree large and heavy for further commercial consideration. The trunk shaker nurseries in Pennsylvania, Oregon, and Washington, and (b) partnering produced canning percentages no lower than 91.5%, and adjusted with commercial technology providers from the outset, so technology fruit values over $872.55 per ton; both equal to that of hand harvested transfer happens as a natural by-product of the effort. control fruit. Final harvest efficiencies ranged from 55.1% to 71.8%. The trunk shaker also produced unacceptable trunk “barking” damage. Specified Source(s) of Funding: Specialty Crops Research Initiative The straddle, over the row, harvester with dual vertical canopy contact (227) Developing Mechanical Harvesting heads was tested in 3 m in-row spacing hedgerow orchards in Argentina and Portugal. The straddle harvester harvested 6–10 trees per minute for California Black Ripe Process Table with a final harvest efficiency of > 95%. Virtually 100% of the fruit Olives Olea europaea Cv. Manzanillo was unacceptably bruised, mutilated or cut. This harvester is unaccept- Louise Ferguson* ably large and heavy. Collectively, this data suggests independently Univ. of California, Parlier, CA; [email protected] powered, double sided continuous movement canopy contact picking Uriel Rosa head harvesters mounted on catch frames with bank out wagons have Univ. of California, Parlier, CA; [email protected] the best potential for efficient, acceptable mechanical harvesting of the immature ‘Manzanillo’ olive that is processed into California’s black Sergio Castro ripe table olive. Our data also suggest tree training and pruning must University of Cordoba, Cordoba; [email protected] proceed in tandem with harvester development Jacqueline Burns Univ. of Florida, Lake Alfred, FL; [email protected]fl.edu Specified Source(s) of Funding: California Olive Commission Kitren Glozer (228) Relationship of Leaf Necrosis and Defoliation Univ. of California, Parlier, CA; [email protected] to Phosphorus and Potassium Concentrations William H. Krueger University of California, Parlier, CA; [email protected] in Selected Tissue and to Certain Fruit Quality Neil O’Connell Parameters of Pecan University of California, Parlier, CA; [email protected] Michael W. Smith* Jorge Mario Ortiz Oklahoma State University, Stillwater, OK; [email protected] Secretario De Agricultura Y Recursos Naturales, La Rioja; Pecan [Carya illinoinensis (Wangenh.) K. Koch] fruit enlarge to full [email protected] size during the first 70-100 days after pollination followed by rapid Jose Luis Ladux cotyledon development the last 30-45 days before ripening (shuck Agencia de Extensión Rural INTA, La Rioja; aerintaimogasta@correo. dehiscence). The primary storage carbohydrate in the seed is oil, ac- inta.gov.ar counting for about 70% of the kernel’s weight. This places an enormous Fabricio Jose Fernandez late-season demand for carbohydrate translocation to the developing Agencia de Extensión Rural INTA Ruta, La Rioja; fjfernandez@correo. fruit followed by oil synthesis. Potassium (K) decreases rapidly in the inta.gov.ar leaves and accumulates in the fruit beginning about 75 days before Peter S. Searles ripening, while rapid phosphorus (P) movement to the fruit begins CRILAR - CONICET; [email protected] about 30 days before shuck split. Potassium allocation patterns ap- John Henry Ferguson pear related to carbohydrate transport during the rapid size increase Ret., CT; [email protected] and continue during cotyledon development. Phosphorus allocation Peter Kulakow appears related to oil synthesis and subsequent P storage in the seed. Ret., CA; [email protected] Trees in an orchard near Cleveland, OK developed necrotic areas in Richard Rosecrance the leaves during the latter part of the growing season. Leaf samples collected during July indicated that P (0.114% DW) and K (0.62% DW) Chico, CA; [email protected] were low, but other elements were within accepted sufficiency ranges.

1110 HORTSCIENCE, VOL. 44(4), JULY 2009 Twenty trees were rated for necrotic symptoms on 1 Oct. 2009 using a pistachio nuts inhibited the growth of a human pathogen, Burkholderia 1 (none) to 5 (severe necrosis and partial defoliation) scale. Fruit (shuck cepacia. Several other species of yeast were reported to control the and nut) were harvested after shuck split (1 Oct.) and 20-fruit samples pathogenic bacteria, Ervinia amylovora, Xanthomonas campestris, were analyzed for weight/nut (pericarp plus cotyledons), kernel weight, Escherichia coli, Listeria monocytogenes, and Salmonella enterica. and graded using the commercial 1 to 4 scale where 1 is best and 4 is a Further research to test the utility of P. anomala in horticutural produc- reject. Leaflet pairs (25/tree) were collected from the middle leaf on fruit tion systems is warranted. bearing shoots 1 October. Leaves, shucks and kernels were analyzed for P and K concentration. Necrosis rating was negatively correlated (252) Identification of Phytohormones in with weight/nut, weight/kernel, and P concentration in the kernel, shuck Vermicompost Tea and leaf. The rating was also negatively related to K concentration in Abira Selvaraj the kernel and leaf. Leaf, kernel and shuck P concentration were posi- University of California, Riverside, CA; [email protected] tively correlated with weight/nut, weight/kernel, and the percentage of Carol J. Lovatt number 1 (best) kernels. Leaf K was weakly correlated to weight/nut University of California, Riverside, CA; [email protected] and weight/kernel. Leaf P concentration was a good predictor of shuck and kernel P concentration, but leaf K was moderately correlated with John Balles shuck K and not related to kernel K concentration. Results suggest Nutrilite, Lakeview, CA; [email protected] POSTERS–Sunday that P and K were limiting, but P appeared to have a greater impact on Milton E. McGiffen* measured parameters than K and leaf P concentration was more closely University of California, Riverside, CA; [email protected] related to leaf necrosis and defoliation than leaf K. Compost tea is an extract prepared by steeping and brewing compost in Specified Source(s) of Funding: credit card water. While the total amount of nitrogen and other nutrients is gener- ally small, compost teas are often reported to stimulate plant growth and prevent diseases. Proposed mechanisms for these benefits include the effects of microorganisms or plant growth regulators that might be Horticultural Crops Culture present in the tea. Analysis of compost tea derived from worm castings (vermicompost tea) revealed high populations of a diverse array of and Management: Organic bacterial species. In addition, radioimmunoassay (RIA) of the phyto- Sunday, 26 July 2009 12:00–12:45 pm hormones present in the vermicompost tea provided evidence that the concentration of the isopentenyladenosine was sufficient to promote a plant growth response at the rates that compost tea is typically applied. (251) Biological Activity and Property of a The vermicompost tea is being analyzed further to quantify the impor- Biopesticide, Pichia anomala tant bacterial groups and concentrations of other hormones (auxins, Sui Shen T. Hua gibberellins and abscisic acid) that might be present in the tea. USDA–ARS Western Regional Research Center, Albany, CA; ssth@pw. usda.gov (253) The Grafted Tomato System: Are There Dan Parfitt* Advantages in the Presence of Soil Borne Diseases? Univ. of California, Davis, CA; deparfi[email protected] Cary L. Rivard Brent Holtz North Carolina State University, Raleigh, NC; [email protected] Univ. of California Coop Extn., Madera, CA; [email protected] Frank J. Louws Siov Bouy L. Sarreal North Carolina State University, Raleigh, NC; [email protected] USDA–ARS Western Regional Research Center, Albany, CA; siov. Suzanne O’Connell [email protected] North Carolina State University, Raleigh, NC; suzanne.oconnell@gmail. com Demand for biological control products has increased in recent decades due to problems associated with the use of chemical pesticides, including Chris D. Harlow resistance, pest resurgence, environmental pollution and risks to human North Carolina State University, Raleigh, NC; [email protected] health. There is a growing interest in including biocontrol agents as part Mary Peet* of integrated pest management systems to promote green technology. North Carolina State University, Raleigh, NC; [email protected] A bioassay has been developed to screen for an effective yeast inhibit- Tomato grafting is widely practiced internationally, mainly to confer ing both the growth of the Aspergillus flavus and aflatoxin production. resistance to soil borne diseases, to improve plant vigor, and to increase The yeast, Pichia anomala strain WRL-076 was tested further for its resistance to abiotic stressors. However, little work has been done in ability to reduce spore production in pistachio flowers and fruits (nuts) the U.S. to determine the benefits of grafting either in the presence as well as on almond and pistachio leaves. Assessment of the efficacy or absence of soil borne disease. During the period 2005–08, grafted of P. anomala in orchard has been achieved by artificially wounding tomato performance was compared with that of non-grafted and self- almond and pistachio nuts on the trees and then spraying the nuts with grafted (those grafted back on their own rootstock) tomato plants in the biocontrol yeast. The results clearly demonstrate that populations replicated experiments on private farms and research stations in NC and of A. flavus and other fungi were significantly reduced on wounded one PA location. Grafted tomato plants demonstrated resistance on-farm nuts. Several properties P. anomala make the species suitable as a to Southern Bacterial Wilt (Ralstonia solanacearum), Fusarium Wilt biological control agent. The yeast strain does not produce allergenic (Fusarium oxysporum), Root-Knot Nematodes (Meloidogyne spp.), spores or mycotoxins. The yeast species is in the category of general Southern Stem Blight (Schlerotium rolfsii) and Verticillium Wilt (Ver- regarded as safe (GRAS). It is found naturally in the orchard. The ticillium dahliae). In most cases, a lower disease incidence was present yeast colonized the plant wound site effectively and inhibited growth for tomato plants grafted on commercial rootstocks and was reflected of A. flavus on the wounds. Results from a number of labs indicated in higher fruit yields. Although he relative advantage of grafted tomato that the P. anomala can control several important fungal pathogens in transplants was greater when soil borne diseases were present, even in post-harvest application. Recently it was shown that sprayed yeast on

HORTSCIENCE, VOL. 44(4), JULY 2009 1111 the absence of soil borne disease, no yield penalty was seen for grafted the first year of this multi-year, multi-disciplinary study. relative to non-grafted tomato plants. However, accurate diagnosis of Specified Source(s) of Funding: USDA-Integrated Organic Program the soil borne diseases likely to be present in the field is critical since no one rootstock was resistant to all the diseases encountered in our (255) The Effect of Weed Control and Tillage on Soil trials In particular, the choice of rootstocks is limited for resistance to Southern Bacterial Wilt, Southern Stem Blight, and specific races of Health in Organic Vegetable Production Verticillium and Fusarium Wilts. Anthony Francis Silvernail* Kentucky State University, Frankfort, KY; [email protected] Specified Source(s) of Funding: SR-SARE, OFRF SR-SARE, OFRF Michael Bomford (254) Organic Versus Conventional Fertilization of Kentucky State University, Frankfort, KY; [email protected] Pac Choi and Tomato Produced in the Field Versus Conducted within a rotation of organic sweet corn and edamame from High Tunnels Influences Crop Yield, Plant and Soil 2005 through 2007, this study measured the effects of tillage and weed control methods upon soil health indicators. Fluorescein diacetate (FDA) Nitrogen, and Phytochemical Content hydrolysis and labile carbon measurements were the tools utilized to May Altamimi* study the effects of weed control and tillage upon a soil’s microbial Kansas State University, Manhattan, KS; [email protected] activity and active carbon content. With the exception of the 2007 Myung-Min Oh August labile C measurements, the conventional (moldboard, rototill) Kansas State University, Manhattan, KS; [email protected] and reciprocating spader tillage treatments had no discernable affect Rhonda R. Janke upon either microbial activity or labile C content. Weed control treat- Kansas State University, Manhattan, KS; [email protected] ments were found to have a significant (P < 0.05) influence upon both microbial activity and labile C content. In 2006 and 2007, seasonal Kimberly A. Williams trends indicated that reductions in microbial activity occurred from the Kansas State University, Manhattan, KS; [email protected] time of planting through harvest. These reductions were particularly Nathan O. Nelson pronounced in the in the top 10 cm of soil in the control and rolling Kansas State University, Manhattan, KS; [email protected] cultivator treatments. During this period, soil from the stale seedbed C.B. Rajashekar and corn gluten treatments maintained a level of microbial activity Kansas State University, Manhattan, KS; [email protected] that was significantly greater than that found in the other treatments. Dorith Rotenberg Similar to the FDA results, labile C measurements from 2005 through Kansas State University, Manhattan, KS; [email protected] 2007, indicated that corn gluten and stale seedbed treatments were Edward E. Carey significantly greater than the other weed control treatments in the July Kansas State University, Manhattan, KS; [email protected] through October samples. Labile C analyses also indicated that samples from the rolling cultivator had significantly lower levels than what was High tunnel production provides a protected environment and extended found in the other weed control treatments. Results indicated that heavily season relative to open field production. An experiment was initiated worked soils in the rolling cultivator and control treatments experienced to study crop yield, soil and plant nitrogen (N), and phytochemical significant declines of microbial activity and labile carbon from plant- content when using organic versus conventional fertility amendments. ing through harvest. However, even with seasonal losses, weed control Spring and fall plantings of pac choi (Brassica rapa L. ‘Mei Qing’) effects upon soil health were limited as evidenced by recovery of lost and a summer planting of tomato (Solanum lycopersicum L. ‘Bush microbial activity and labile C by the following spring. Celebrity’) were used to examine the effect of fertility rate (control, low, and high) and source [conventional (Conv) and organic (Org)] in Specified Source(s) of Funding: Evans-Allen different production systems [high tunnel (HT) and field (F)]. The ex- periment was conducted in 2008 at the KSU Research Center in Olathe (256) Interdisciplinary Vegetable Pest Management in replicated HT and F plots. Control plots received no supplemental Potentials of Selected Cover Crops fertilizer, low plots received pre-plant fertilizer of 20 N: 4.4 P: 16.6 K Oli Bachi (Conv) or mixed source compost (0.6 N: 0.4 P: 0.4 K; Org), and high University of California, Riverside, CA; [email protected] plots received the same pre-plant amendments plus soluble fertilizers Antoon Ploeg of KNO3+ Ca(NO3)2 (Conv) or fish hydrolyzate (Org). All plots had University of California, Riverside, CA; [email protected] cover crops of rye (Secale cereal L.) during the winter and buckwheat Gregory Walker (Fagopyrum sagittatum Gilib.) in the summer between pac choi crops. University of California, Riverside, CA; [email protected] Soil NO3-N and NH4-N were measured, as well as NO3-N in leaf petiole sap, based on the crop stage. Phytochemical content of pac choi leaves Milton E. McGiffen* and tomato fruit were measured as total phenolics and antioxidant University of California, Riverside, CA; [email protected] capacity. Soil NH4-N and NO3-N levels were affected by production Field experiments in Irvine, California measured pest populations system, and fertility source and rate, but statistical significance varied in broccoli planted after two summer cover crops, cowpea (Vigna by crop and stage. Petiole sap NO3-N reflected treatment regimes but unguiculata, cultivar UCR CC 36) and marigold (Tagetes patula cv. not necessarily soil N status at each plant stage. Phytochemical data Single Gold). Of the weed pests, we observed that Portulaca oleracea showed treatment differences between F and HT, but no clear or con- (common purslane) was the dominant species and that its population sistent differences between Conv and Org. Yield of pac choi was higher density peaked just before the first hand weeding at 184 plants per m2 in HT than F in both spring and fall. Yield of Org pac choi in both HT in broccoli following fallow. This weed also measured the highest dry and F was higher than Conv in the fall but not the spring. Pac choi biomass for broccoli planted after the fallow summer field. The fallow yield in general reflected fertility rates. Tomato yield was also higher treatment had 5x as many purslane just before the first hand-weeding in HT compared to F. Org HT tomato had higher yield than Conv, but as when broccoli followed cowpea and 10× more than the marigold no significant differences were observed in F. Tomato yield differences treatment. The population density of all weeds ranged from 216 plants for fertility rate were significant in F but not in HT. The 2008 season is in fallow plots to 54 and 42 plants in broccoli planted after cowpea

1112 HORTSCIENCE, VOL. 44(4), JULY 2009 and marigold, respectively, just before the first weeding. By harvest, lesser yield. In this study results shown, mulching increased the yield the population of all weed spp. was 4× higher in broccoli planted on of cucumber by 27% over no mulch. previously fallow plots relative to those in the cowpea and marigold Specified Source(s) of Funding: Alcorn State University plots. The predominant broccoli insects were Trichoplusia ni (Cab- bage loopers), Pieris rapae (cabbage worm) and Plutella xylostella (258) Effect of Cultivar and Pest Management on (diamondback moth), with loopers the most damaging. Insect pest populations were inconsistent between the cropping systems. However, Organic Sweet Corn Production the total number of insects was relatively higher on broccoli planted Kathleen Delate* after the cover crops during the initial growth period than those planted Iowa State University, Ames, IA; [email protected] into the fallow beds. Insects appeared to prefer more rapidly growing Organic agricultural sales increased to a $20 billion in the U.S. in 2008 broccoli and relatively younger leaves, as leaf damage was greatest and continue to maintain momentum despite the economic downturn depending on the growth stages of crops. Broccoli height and canopy in the U.S. In the last five years, additional organic seeds have be- spread were greater following either cowpea, a nitrogen fixing legume, come available to aid compliance with the USDA–National Organic or marigold. While broccoli following cowpea and marigold had the Program requirement that organic producers source certified organic greatest leaf damage, particularly at younger stages, its yields were seed/cultivars for their operations. Among the most important production POSTERS–Sunday also highest in terms of both weight and number of heads. Market- issues for organic sweet corn in the Midwestern U.S. are managing soil able broccoli heads were 115, 90 and 81 from cowpea, marigold and fertility and timely pest management. This project investigated cultivar fallow plots, respectively. Similar trends were observed on the fresh selection from organic and conventional seed and the efficacy of the weights of the marketable yields. Broccoli plants grown after cover naturally occurring soil bacterium, Bt (Bacillus thuringiensis kurstaki), crops matured faster than those that were planted following a summer for improved pest management of the corn earworm (Heliocoverpa zea). fallow. In general, there are indications that summer cover crops reduce Treatments were applied to the corn ears when 50% were silking, and multiple crop pests for a subsequent commercial crop. Although a cover 2 to 4 days later, using a pressurized backpack sprayer. Results from crop may not provide complete pest control on its own, it may play these four-year trials show great variability in earworm damage, ranging a valuable role as a tool in any integrated pest management system, from 0% to 66% damage, depending on the year. Overall performance particularly for organic vegetables. of organic sweet corn was excellent, with yields ranging from 12,894 Specified Source(s) of Funding: USDA–ARS Crops At Risk grant to 20,790 ears/acre. Earworm damage varied by cultivar but there were program. no differences between organic and conventional cultivars. There was a trend toward less earworm damage in the organic Bt treatments, but (257) Assesment of Various Mulches for Organic the damage was not significantly less than the control (no spray). These Production of Cucumber experiments were conducted from May to July when warm air and soil temperatures ensured rapid emergence and growth. Organic sweet corn Reddy, R. Chinthakuntla* destined for earlier or later markets may encounter increased pressure Alcorn State University, Alcorn State, MS; [email protected] from corn earworm populations. Patrick Igbokwe Alcorn State University, Alcorn State, MS; [email protected] Specified Source(s) of Funding: Leopold Center for Sustainable Ag- Rao. S Mentreddy riculture Alabama A&M University, Huntsville, Al, Huntsville, AL; (259) Estimated Nitrogen Balance of Young Apple [email protected] Frank Matta Trees Grown in Response to Various Organic Apple Mississippi State University, Starkville, MS; [email protected] Production Systems Currently organic production demand is rapidly expanding at ap- Hyun-Sug Choi* proximately 23% annually and organically produced vegetables fetch University of Arkansas, Fayetteville, AR; [email protected] premium prices compared to conventionally produced vegetables. Or- Curt R. Rom ganic production continues to be a small-scale niche-market enterprise, University of Arkansas, Fayetteville, AR; [email protected] but weeds are a major problem limiting its expansion. Different types Annual nitrogen (N) balance can be very useful information for farmers of mulches have been used to increase yields through weed control, to estimate N loss and surplus after the growing season, especially at the better soil moisture conservation, and soil temperature regulation in farms where a large amount of N input is applied. A certified organic organic production systems. A field trial was conducted at Alcorn State apple orchard was established to study the interaction of ground cover University during the 2008 growing season, with the objective of assess- management systems and nutrient sources on orchard performance ing mulching effects on cucumber in organic production system. The in the southern region of the US in 2006. Trees received one of four plots were arranged in a randomized complete block design with two ground cover management treatments as an under canopy mulch: 1) mulching treatments: wood mulch, pine mulch, and control (no mulch) urban green compost (GC); 2) refuse wood chips (WC); 3) shredded as the main plots and three cucumber varieties obtained from Cornell commercial paper (SP); and 4) mow-and-blow vegetation (MB). Across University, as the sub-plots. Each treatment was replicated three times all ground covers, one of three nutrient source treatments was applied: on rows 24” x 36”. All varieties were evaluated for insect and disease A) a commercial pelletized; poultry-based product (CF); B) composted resistance, yield and fruit characteristics. Organic fertilizers (cotton seed poultry litter (PL); C) control—the ground cover treatment provides meal, bone meal and blood meal) were applied, whereas insects and nutrients (NF). GC and WC treated trees had significantly higher total diseases were controlled with organic (Neem extraction) triple action. leaf nitrogen (N) content and leaf nitrogen use efficiency (LNUE) which Mulching cucumber with wood chips or pine straw resulted in a total was strongly correlated with trunk cross sectional area (TCSA) in the fruit yield of 33.5 and 29.0 kg/plant, respectively, compared to 24.5 third year. The estimated annual N surplus was ranged 23 to 1453 g kg/plant from control treatment. Among varieties both Marketmore and of N per tree. GC with any fertilizers had the highest N surplus and Poinsett with an average of 3.7 kg/harvest produced a seasonal total [NO3-N] in soil solution at 30 cm depth in mid-September. Therefore, yield of 12 kg/plant, whereas, Control plants produced about 8.5% GC treated tree had more risk for N leaching or immobilization dur-

HORTSCIENCE, VOL. 44(4), JULY 2009 1113 ing non growing season when the trees are not actively taking up N. evaluate the main effects and interactions of four ground cover manage- In order to observe which production systems could be more efficient ment systems and three nutrient source strategies that may be used in an for tree growth and reducing N loss, three dimensional graphs for the organic orchard. The four ground cover management treatments were: 1) TCSA, LNUE, and N surplus showed that WC treated trees had the municipal green compost (GC); 2) wood chips (WC); 3) shredded white highest TCSA and LNUE and comparably low N surplus than GC paper (SP); and 4) managed vegetation with a mow-and-blow mulch treated trees. GC treated trees had the lowest photosynthetic nitrogen system (MB). The three nutrient source treatments were: 1) control (NF); use efficiency during July, August, and September. 2) composted poultry litter (PL); and 3) certified organic commercial poultry litter based fertilizer (CF). In the NF treatment, nutrients were Specified Source(s) of Funding: Graduate school provided by the four ground cover treatment provided above. Trees of (260) Protected Cultivation of Peach as Technique ‘Enterprise’/M26 were planted in 2006 at a density at a 600 trees/acre and trained to a modified vertical axis system. Experimental design for Organic Production was a split-plot with main units completely randomized in 6 blocks. Flavio Roberto De Salvador* Main units were groundcover treatments (n = 4) and sub-units were CRA-Tree Fruit Research Center, Rome; [email protected] fertilizers (n = 3). Weed density during the season was measured with a Carlo Fideghelli color-difference photographic system to differentiate vegetative cover CRA-Tree Fruit Research Center, Rome; isfrmfi[email protected] from ground cover surface. In the first two seasons, the GC and MB treatments had significantly higher weed density than either the WC Due to the increasing awareness in Italy about the pesticide use on or SP. Beginning in year 3 of the study, surface cultivation under the edible products, there is a progressive expansion of organic growing trees was begun. Cultivation resulted in a strip approximately 50 cm cultivation of fruit crops, mainly in the South of the country.Among wide on either side of the tree with a 50-cm vegetation strip contact fruit crops, early ripening peach cultivars have limited pest problems, tree to tree. After cultivation, weed density was similar for GC, WC while the risk of insect and fungal attacks increases consistently for and SP (approximately 15% to 20%), but significantly higher in the MB late and very late varieties.Mediterranean fruit fly (Ceratitis capitata, treatment (40%). There was no difference in weed density among the Wiedemann ), with its numerous generations and fungal diseases, nutrient source treatments. During a snow and ice episode in winter agent of fruit decay promoted by rain, require a high use of chemicals 2008, significant vole activity and damage occurred in the orchard. to protect the fruits, making very difficult to follow the organic crop Damage was rated and number of trees damaged counted. Damage production protocol. The aim of this research was to evaluate the ef- ratings were highest and most severe in the MB treatments and lowest fectiveness in controlling pests (insects and fungal diseases) through in the WC. The GC and SP treatments were intermediate. There was the use of tunnel, with permanent screen wire netting (16 mesh white no significant difference among the nutrient source treatment for vole polypropylene, solar transmittance 88%) and temporary LPDE film damage ratings. The greatest tree death (approximately 35% of all (low density polyethylene 0.2 mm thick) to protect the canopy and the planted trees) occurred in the MB treatments while the GC and WC fruits from rain, 4–6 weeks before harvest.The trial was carried out had less than 5% tree loss. Tree death was relatively uniform across in the years 2006–08, in Rome (Italy), on the peach cultivars Imera, the nutrient source treatments. Xirbi, Entella, Tudia, Aso20, Tardiva di Calanda and the nectarine California. The ripening period was from end of September through Specified Source(s) of Funding: USDA-IOP middle November. The trees were planted at 1.5 m on the row and 5.0 m between the row, trained as simplified Tatura trellis. In the covered (262) Performance of High Tunnel Organic cultivation were not evident, damages caused by Mediterranean fruit fly Blackberry and Raspberry (Ceratitis capitata, Wiedemann), Oriental fruit moth (Cydia molesta, H. Friedrich* Busck) and Peach twig borer ( Anarsia lineatella, Zeller), while outside University of Arkansas, Fayetteville, AR; [email protected] the tunnel no marketable fruits were harvested. Plastic film reduced Curt R. Rom fruit rot infections to a level of 0.5% to 1.0%, regardless the external University of Arkansas, Fayetteville, AR; [email protected] unfavorable weather conditions. Fruit weight was always higher in the net-film covered treatment, while the skin color was lighter; the J. McAfee total soluble solids content was higher under net, the titratable acidity University of Arkansas, Fayetteville, AR; [email protected] lower. Under the tunnel, vegetative activity was enhanced and leaves M. Elena Garcia showed a delayed senescence evidenced also by very high level of University of Arkansas, Fayetteville, AR; [email protected] photosynthesis, still measured at the end of the growing season. D.T. Johnson University of Arkansas, Fayetteville, AR; [email protected] Specified Source(s) of Funding: CRA-Fruit Tree Research Center - Rome J.S. Popp University of Arkansas, Fayetteville, AR; [email protected] (261) Ground Cover Management and Nutrient C. Vincent Source Affect Weed Density, Vole Damage, and University of Arkansas, Fayetteville, AR; [email protected] Survival During Establishment of an Organic Apple High tunnels have been used to extend production and improve the Orchard quality of many vegetables and fruits. Recently high tunnels have been employed in the production of high-value fruit crops such as blackber- Jason D. McAfee* ries and raspberries. The University of Arkansas initiated two studies to University of Arkansas, Fayetteville, AR; [email protected] investigate the use of high tunnels to modify the harvest period of both Curt R. Rom primocane and floricane fruiting blackberries and raspberries. Study 1 University of Arkansas, Fayetteville, AR; [email protected] was a comparison of three floricane fruiting blackberries (‘Navaho’, Primary problems in organic orchards are ground cover management ‘Ouachita’, and ‘Arapaho’) and raspberries (‘Dormanred’, ‘Prelude’ and application of sufficient nutrients to sustain growth. An unintended and ‘Encore’) in open-field vs high tunnel production with the goal to consequence of ground management practices may be an increase of advance the spring harvest. Study 2 included three primocane fruit- new pests in the orchard. An experiment was established in 2006 to ing blackberry (‘Prime-Jim’, ‘Prime-Jan’ and APF46) and raspberry

1114 HORTSCIENCE, VOL. 44(4), JULY 2009 cultivars (‘Autumn Bliss’, ‘Caroline’, and ‘Dinkum’) in field vs high Specified Source(s) of Funding: Departmental fund tunnel production with the goal of delaying harvest using pruning methods and extending harvest with high tunnels. Genotype evaluation (171) Post-transplant Irrigation Scheduling for Two in the high tunnel environment is necessary to achieve season extension Native Deciduous Shrub Taxa goals. Early or late flowering traits are important considerations when Abby L. Bailey selecting genotypes for advancing spring or delaying autumn produc- Auburn University, Auburn, AL; [email protected] tion, respectively, and some genotypes performed better in high tunnels Amy N. Wright* while others do not. Primocane and floricane fruiting raspberries and Auburn University, Auburn, AL; [email protected] floricane fruiting blackberries performed better in tunnels, achieving greater yields, larger berry size and a higher percentage of marketable The effect of five irrigation scheduling treatments on shoot growth and fruit compared to open field production. Primocane fruiting blackberry photosynthetic rates of Itea virginica L. ‘Henry’s Garnet’ (‘Henry’s production performance in high tunnels was genotype dependent. Garnet’ sweet spire) and Rhododendron austrinum Rehd. (Florida flame While ‘Prime Jim’ and APF 46 both performed better inside the high azalea) were studied. On 13 March 2008, twenty-five 11.4 L (3 gal.) tunnels, ‘Prime Jan’ had greater yield in open-field conditions with no plants of each taxa were planted 1.2 m (4 ft.) on center in field plots difference in berry size. in Auburn, AL. I. virginica ‘Henry’s Garnet’ was planted under 30% shade and R. austrinum was planted under 47% shade. Watermark® POSTERS–Sunday Specified Source(s) of Funding: University of Arkansas soil moisture sensors (model 900M) were installed in the root ball and surrounding soil of plants in three replications per treatment. Five irrigation scheduling treatments were used: root ball and surrounding soil maintained at or above -25 kPa (well-watered, WW); root ball and Horticultural Crops Culture and Management: surrounding soil re-watered when root ball moisture reached -50 kPa Ornamental Crops (50 RB) or -75 kPa (75 RB); root ball and surrounding soil re-watered Sunday, 26 July 2009 12:00–12:45 pm when surrounding soil moisture reached -25 kPa (25 S) or -50 kPa (50 S). When irrigated, plants received 2.5 cm (1 in) of water applied by hand in a 31 cm (12 in) radius around the plant [7.4 L water (1.9 gal)]. (170) Conversion of Ammonium to Nitrate in a Pine Growth index (GI) of plants was measured at planting and at the end Tree Substrate of the first growing season (7 October 2008), and relative growth index Linda L. Taylor (RGI) was calculated. Photosynthetic rates (Ps) of plants were measured VPI & SU, Blacksburg, VA; [email protected] on 29 August 2008 for R. austrinum and 6 October 2008 for I. virginica ‘Henry’s Garnet’. Shoots of I. virginica ‘Henry’s Garnet’ grew almost Alex X. Niemiera twice as much as those of R. austrinum. In I. virginica ‘Henry’s Garnet’, VPI & SU, Blacksburg, VA; [email protected] RGI was highest in plants that were WW and re-watered at 25 S moisture Robert Wright followed by those re-watered at 50 S, 75 RB, and 50 RB moisture. R. VPI & SU, Blacksburg, VA; [email protected] austrinum RGI was highest in 75 RB, 50 RB, and WW treatments and J. Roger Harris* lowest for plants in the 25 S and 50 S treatments. In spite of growth VPI & SU, Blacksburg, VA; [email protected] differences, Ps was not significantly different between taxa or among Pine tree substrate (PTS), a relatively new substrate for container-grown treatments. Data for soil and root ball drying rates suggest faster root plants, is manufactured by chipping, then milling, pine (P. taeda) logs. growth rates in I. virginica and the importance of monitoring root ball Nitrification in PTS, pine bark (PB), and a peat-based substrate (PL) moisture for species like R. austrinum that may have slower rates of was studied by measuring nitrate accumulation biweekly for 12 weeks. root growth. Both taxa were able to maintain shoot growth, Ps, and Treatments were: 1) PTS without lime (PTS); 2) PTS with 1.8 kg·m-3 visual quality in all treatments, indicating that scheduling irrigation lime (PTSL); 3) PTS amended with PB (PTSPB) in a ratio of 3PTS:1PB, based on soil and root ball moisture can result in decreased irrigation and 1.8 kg·m3 lime; 4) PTS amended with peat moss (PTSP) in a ratio frequency without decreasing plant survival. -3 of 4PTS:1 peat moss, and 1.8 kg·m lime; 5) PB amended with 3.6 (172) Short Interval Cyclic Flooding Affects Growth kg·m-3 lime; and 6) PL amended with 5.4 kg·m-3 lime. Substrates were -1 and Physiology of Three Native Shrub Taxa placed in 1 L containers and fertilized with a 300 mg·L NH4 – N fertil- izer solution weekly to biweekly. Substrate solutions were extracted Katie L. Werneth from container substrates by the saturated medium extract method, and Auburn University, Auburn, AL; [email protected] subsequently analyzed for ammonium-N and nitrate-N. From weeks 2 Amy N. Wright* to 12, substrate pH decreased by 0.3, 0.5, 0.8, 0.8., 1.1, and 1.2 units Auburn University, Auburn, AL; [email protected] for the PTS, PTSL, PTSPB, PTSP, PB, and PL substrates, respectively. Plant species adapted to wet conditions are likely candidates for rain After 12 weeks, nitrate was not present in any of the PTS substrates. In gardens due to their ability to withstand alternating wet and dry periods. contrast, at week 4, nitrate concentrations for PB and PL were 5 and 3 On 16 June 2008, rooted stem cuttings [0.25 L (2.25 in)] of Viburnum mg·L-1, respectively, and week 12 nitrate concentrations were 82 and nudum L. ‘Winterthur’ (possumhaw), Ilex glabra (L.) A. Gray. ‘Sham- 78 mg·L-1, respectively. In all weeks (except week 8), PTSL had lower rock’ (inkberry holly), and Itea virginica L. ‘Henry’s Garnet’ (sweetspire) NH –N concentrations than PTS, indicating 1) greater adsorption to 4 were potted in 2.5-L (trade gal) containers and arranged in a randomized substrate particles, 2) possible oxidation by nitrifying microorganisms, complete-block design with 5 blocks in a greenhouse in Auburn, AL. without measurable nitrate due to subsequent immediate immobiliza- Beginning on 21 July 2008, plants were flooded to substrate level for tion, and 3) consumption by a potentially greater microbe population 0 (non-flooded control), 3, or 7 days and then allowed to drain for one (enhanced by the relatively high substrate pH in this limed substrate). week before the same flood cycle was repeated. Photosynthesis (Ps) The apparent lack of nitrification in PTS (inferred by no nitrate detec- rates were measured for V. nudum ‘Winterthur’ and I. virginica ‘Henry’s tion) will significantly influence the choice of nitrogen fertilizers for Garnet’ during flooding and draining cycles in plants flooded for 3 and 7 growing crops in PTS. days with concurrent measurement of Ps of non-flooded control plants.

HORTSCIENCE, VOL. 44(4), JULY 2009 1115 On 10 Oct. 2008, the experiment was terminated. Non-flooded plants (174) Comparative Studies Between Acclimatization of I. virginica ‘Henry’s Garnet’ and I. glabra ‘Shamrock’ had higher and Cultivation of Hook-Moss Grown in growth indices (GI) [(height + widest width + width perpendicular to widest width)/3] than plants flooded for 3 or 7 days. Shoot dry weight a Vinyl House (SDW) of I. glabra ‘Shamrock’ was lower when plants were flooded for Ju Kwang Hwang* 7 days than when flooded for 0 or 3 days. SDW for I. virginica ‘Henry’s Chungbuk National University, Cheongju, Chungbuk; Garnet’ was higher in non-flooded plants than plants flooded for 3 or 7 [email protected] days. I. virginica ‘Henry’s Garnet’ root dry weight (RDW) was higher in M.G. Ahmed non-flooded plants and plants flooded for 3 days, than in plants flooded Chungbuk National University, Cheongju, Chungbuk; for 7 days. RDW for I. glabra ‘Shamrock’ was highest in non-flooded [email protected] plants, followed by plants flooded for 3 or 7 days. RDW, SDW, and Y.D. Chang GI for V. nudum ‘Winterthur’ were not different among treatments. I. Chungbuk National University, Cheongju, Chungbuk; changyd01@paran. virginica ‘Henry’s Garnet’ Ps rates were higher during flooding than com during draining in both flooding treatments, and Ps rates were higher Daeil Kim in control plants than in flooded plants. V. nudum ‘Winterthur’ Ps rates Chungbuk National University, Cheongju, Chungbuk; were similar in non-flooded and flooded plants indicating its ability to [email protected] tolerate flooding and maintain rates of Ps. Although growth and Ps of C.H. Lee I. virginica ‘Henry’s Garnet’ and I. glabra ‘Shamrock’ were generally Chungbuk National University, Cheongju, Chungbuk; leech@chungbuk. lower in flooded plants than non-flooded plants, all taxa maintained ac.kr visual quality and continued to grow which suggests they all would be acceptable choices for use in rain gardens. Acclimatization and cultivation investigations with Cratoneuron decipiens of temperate moss has been performed under vinyl house (173) Growth and Photosynthesis of Selected Native conditions. For both studies hook-moss was cultivated with different Shrubs Planted Above-grade with Organic Matter growing media, propagation systems, inoculum densities, light shade, and watering methods. Plant materials for acclimatization were grown Scott B. Hanes through suspension culture with Knopp (1865) macro salts and Nitsch Auburn University, Auburn, AL; [email protected] and Nitsch (1956) trace elements. Vegetative propagation is the basis Amy N. Wright* for the moss production. Three types of propagation systems (direct Auburn University, Auburn, AL; [email protected] sowing, suspension, and chopping of gametophytes) were examined in In modified above-grade landscape planting, substrate is mounded this experiment. Longest and highest numbers of gametophytes were around the upper portion of a root ball that remains above soil grade at produced by direct sowing for both culture conditions. Maximum planting in order to mimic the natural organic litter layer that supports number of gametophte/flax was produced by 1 g inoculum density but root growth in naturalized landscapes. On 17 March 2008, 3-gal. plants percent fresh and dry weight per 10 gametophytes were increased in of Chionanthus virginicus L., Rhododendron austrinum Rehd., and 0.5 g inoculum density for all conditions. According to our findings Hydrangea quercifolia Bartr. ‘’ were planted in field plots 1.2 m (4 ft.) peat and perlite mixture in 5:1 (vol:vol) was beneficial to cultivation, on-center, and the planting hole was backfilled to soil grade with existing and bark and perlite mixture in 3:1 ratio was suitable for acclimati- field soil. Plants were planted at grade (AG) with no organic matter or zation. Light shade of 50% showed the highest positive influences above grade with one of four organic substrates: peat moss (PM), pine on gametophytee number, and on fresh and dry weight for moss bark (PB), pine tree substrate (PT), or coconut coir (CC). In above grade production, but 70% shade resulted in longest and highest number plantings, plants were planted such that the top 10 cm (4 in.) of the root of gametophytes during acclimatization. Surface watering was better ball remained above grade, and organic matter was mounded around than sub-surface watering for both culture conditions. In order to get the above-grade portion of the root ball, extending outward from the adequate acclimatization and cultivation conditions, the established stem in a radius of 31 cm (12 in.). C. virginicus and H. quercifolia were methods were modified. planted under 30% shade, while R. austrinum was planted under 47% Specified Source(s) of Funding: Chungbuk National University, shade. On 19 September 2008, net photosynthesis (PS) was measured for Korea each plant. Growth indices [(widest width measurement + perpendicular (^) width measurement + height)/3] were recorded at planting (initial (175) Influence of Daily Light Integral on Coleus growth index, IGI) and on 23 October 2008 (final growth index, FGI). Morphology and Leaf Variegation IGI and FGI were used to calculate relative growth index [RGI = (FGI - IGI)/IGI]. Treatments were arranged in a randomized complete block Katherine Garland* design with five blocks. C. virginicus plants were smallest at planting, University of Maine, Orono, ME; [email protected] yet had the highest RGI (1.7) among taxa, followed by H. quercifolia Stephanie Burnett (0.8) and R. austrinum (0.6). RGI was not different among treatments University of Maine, Orono, ME; [email protected] for C. virginicus and R. austrinum, however, RGI was lowest in PB for Lois Berg Stack H. quercifolia. PS rates were not different among treatments, yet were University of Maine, Orono, ME; [email protected] highest in R. austrinum (19 µmol·m2·s), followed by C. virginicus (16 Donglin Zhang 2 2 µmol·m ·s), with H. quercifolia being lowest (6 µmol·m ·s). Differences University of Maine, Orono, ME; [email protected] in growth and PS among taxa are likely related to inherent genetic Solenostemon scutellariodes differences, and similar PS rates among treatments correspond with Coleus [ (L.) Codd] is an ornamental the lack of growth differences among treatments. Correlation between foliage plant valued for its colorful variegation patterns. Cultivars PS and RGI for C. virginicus and H. quercifolia ‘Alice’ but not for R. of coleus are able to tolerate a broad range of light conditions. How- austrinum may explain differences in ease of landscape establishment of ever, the leaf variegation that coleus is valued for has been noted these taxa. All substrates appeared to be suitable for use in this planting to change depending on the amount of light in which it is grown. technique with these taxa. Successful coleus sales rely on a combination of dramatic coloration

1116 HORTSCIENCE, VOL. 44(4), JULY 2009 and dense growth habit. To our knowledge, the exact light conditions (177) Target Region Amplification Polymorphism required to promote these characteristics have not been determined. (TRAP) for Evaluating Genetic Diversity in Malus Therefore, two cultivars of coleus, ‘Kong Red’ and ‘Wizard Coral Sunshine’, were grown under four daily light integrals (DLI) (10.0, Mill. Genus 5.8, 3.8, and 2.9 mol·m-2·d-1) to determine the optimal light level for Ling Guo* production. ‘Kong Red’ and ‘Wizard Coral Sunshine’ coleus grown Beijing Botanical Garden, Beijing 100093; [email protected] under a DLI of 2.9 mol·m-2·d-1 exhibited reduced leaf areas of 66% Rose Palumbo and 63%, respectively, compared to those grown under a DLI of 10.0 The Ohio State University, Columbus, OH; [email protected] -2 -1 mol·m ·d . The number of leaves per plant followed the same trend, Zuoshuang Zhang decreasing 64% in both cultivars when comparing those produced Beijing Botanical Garden, Beijing; [email protected] under the lowest and highest DLI treatments. Percent non-green area Guo-liang Wang per leaf decreased by 18% for ‘Kong Red’ and by 23% for ‘Wizard The Ohio State University, Columbus; [email protected] Coral Sunshine’ produced under 2.9 mol·m-2·d-1 compared to plants grown under 10.0 mol·m-2·d-1. Overall, both cultivars exhibited a David Tay more dense growth habit and greater degree of variegation (relative International Potato Center, Lima; [email protected] percent of non-green area per leaf) when grown under the highest Donglin Zhang POSTERS–Sunday DLI. Therefore, we recommend growing these two cultivars under a University of Maine, Orono, ME; [email protected] minimum DLI of 10.0 mol·m-2·d-1. Xiang Shen Shandong Agriculture University, Tai’an; [email protected] Specified Source(s) of Funding: Maine Agricultural Center Integrated Research and Extension Grant Huairui Shu Shandong Agriculture University, Tai’an; [email protected] (176) Several Factors Affecting In Vitro Mass Malus belongs to Rose family and has 8-55 (78) species depending on Propagation and Morphogenesis in Prothalli of various classification systems. Also, many synonyms and homonyms Pteris cretica Wilsonii were existed. There are more than 7500 apple cultivars and more than 500 flowering crabapple cultivars in the world. Most of them were Ju Kwang Hwang* bred by open pollination and a few of them were controlled crosses. Chungbuk Natl University, Cheongju, Chungbuk; jkhwang@chungbuk. ac.kr TRAP (Target region amplification polymorphism) was applied for elucidating genetic relationships in Malus genotypes. TRAP is a S.L. Shin novel PCR-based molecular marker technique which uses gene-based Chungbuk Natl University, Cheongju, Chungbuk; sorim0917@hanmail. information for primer design. 43 Malus samples from 27 species and net varieties, 8 hybrid species, and 8 cultivars were selected for TRAP Daeil Kim maker system analysis. Two fixed primers, designed using matK gene Chungbuk Natl University, Cheongju, Chungbuk; dkpomo@chungbuk. sequences of Malus sieboldii, paired with two arbitrary primers, were ac.kr used to conduct TRAP PCR. A UPGMA dendrogram was generated C.H. Lee based on a total of 197 unambiguous bands. Among them, 182 were Chungbuk Natl University, Cheongju, Chungbuk; [email protected] polymorphic with an average of 45 polymorphic bands per primer Present studies were undertaken to establish the mass propagation combination.The bands ranged in size from 75 to 700 bp. TRAP PCR systems by examining adequate environmental conditions for cultur- cluster analysis revealed that the closer relationships in the dendro- ing prothalli of Pteris cretica. Chopped prothalli were inoculated on dram of Malus samples are in agreement with the originations of these 3 kinds of medium: 1/8, 1/4, 1/2, 1, and 2X MS with 3% sucrose and genotypes. TRAP is a potentially useful marker technique for genetic 0.8 agar, 0.3% Hyponex (N:P:K = 6.5:6:19), and Knop medium. The diversity studies in Malus genus. multiplication and growth of prothalli was highest with Hyponex me- dium. To see the effects of sucrose concentrations prothalli were again (178) Ornamental Peppers for the Gulf States inoculated on Hyponex and MS medium containing 0 ~ 5% sucrose, William Evans and the highest growth was obtained with Hyponex with 1% sucrose. Mississippi State University, Crystal Springs, MS; [email protected] Most prothalli did not survive on MS medium containing sucrose, but in Yan Chen* some prothalli the formation of parenchyma tissues, not gemmae, was Louisiana State University, Hammond, LA; [email protected] observed. Divided in groups or chopped prothalli were placed on 3 media Crofton Sloan and results showed that division was better with MS, whereas chopped Mississippi State University, Verona, MS; [email protected] was with Hyponex. The agar concentration of 0.6% was most effective Susan Harkness in prothallus multiplication. Solid and liquid medium (stationary or Mississippi State University, Verona, MS; [email protected] shaking) were employed in this experiment and solid medium proved to be effective in prothallus multiplication. The prothalli continued to This study investigated the garden performance of ornamental pepper multiply by the formation of gemmae in liquid shaking culture, but (Capsicum sp.) cultivars at Hammond, Louisiana, and at Crystal Springs in solid culture parenchyma tissues were formed. This indicates that and Verona, Mississippi, over two years. Over thirty entries were evalu- liquid shaking culture might be preferred for prothallus proliferation ated in replicated plot at each location, with more than twenty-five if cultured more than 8 weeks. In conclusion, solid culture should be entries common to all three locations. The trial was of smaller fruited used if the sporophyte formation by prothalli is wanted, but if mass peppers, not C. annuum bell-type peppers. Each plot was rated on a propagation of prothalli is desired, liquid shaking culture is favored one to five scale monthly over the three to four month growing season even if it takes longer time. for plant shape, uniformity, attractiveness of fruit, attractiveness of foliage, and overall garden performance. Cultivar performance varied Specified Source(s) of Funding: Chungbuk National University, across sampling dates within location. Across locations, cultivars often Korea received similar ratings. Among the higher rated cultivars, ones that

HORTSCIENCE, VOL. 44(4), JULY 2009 1117 performed well at all locations and were rated highly in most or all The relationship between the total amount of micronutrients absorbed categories were: Bolivian Rainbow, Black Pearl, Sweet Pickle, Super by the above-ground plant part and the occurrence of visible micro- Chili Hybrid, Chilly Chili, Explosive Ember, Numex Centennial, and nutrient deficiency symptoms in strawberry (Fragaria×ananassa Marbles. These appear to have garden merit, performed well in three Duch.) as influenced by elevated phosphorus (P) levels in fertigation environments, and are likely to please most gardeners in the region. solution was investigated. Stolon-propagated plants of two strawberry Several other cultivars in the trial were also of merit but were either cultivars, ‘Seonhong’ and ‘Keumhyang’, were cultured in the field and not planted at all three locations, rated lower in one or more categories irrigated with a standard fertilizer solution containing 0, 0.5, 1, 2, 4, across the three locations, were more variable in ratings within or or 6 mM P. Dry matter yield and tissue nutrient content were deter- among locations than others, or were rated among the best cultivars at mined on plants harvested 120 days after transplanting. Plant growth only one or two locations. response to increased P levels in fertilizer solution was cubic, with the highest dry matter production occurring at 0.5, 1.0 and 2.0 mM P Specified Source(s) of Funding: CRIS MIS-149090 and others in ‘Keumhyang’ and at 0.5 and 1.0 mM P in ‘Seonhong’. The pattern of P accumulation in the tissues of the two cultivars as influenced by Horticultural Crops Culture and Management: elevated nutrient solution P levels showed a quadratic response, while Plant Nutrition the total amount of P contained by the above-ground plant part decreased when P concentration in nutrient solution was higher than 4 mM in Sunday, 26 July 2009 12:00–12:45 pm ‘Keumhyang’ and 2 mM in ‘Seonhong’. Young leaves of the plants grown with nutrient solution P levels higher than 4 mM and 2 mM, (163) Silicon Fertilization of Potted Orchids respectively, in ‘Keumhyang’ and ‘Seonhong’, developed interveinal chlorosis with pale green color. Tissue concentrations of iron (Fe), Wagner A. Vendrame* copper (Cu), manganese (Mn) and zinc (Zn) in both cultivars, when University of Florida, Homestead, FL; vendrame@ufl.edu expressed as mg·kg-1 dry weight, did not decrease even in the treat- Ania Pinares ments in which deficiency symptoms were observed. The total amount University of Florida, Homestead, FL; apinares@ufl.edu of these metallic micronutrients absorbed by the above-ground plant Aaron J. Palmateer part decreased in the treatments in which nutrient deficiencies were University of Florida, Homestead, FL; ajp@ufl.edu observed. The total amount of absorbed micronutrients showed a cubic Lawrence E. Datnoff response to increasing P levels in nutrient solution. Result of this study Louisiana State University, Baton Rouge, LA; [email protected] indicates that total amount of micronutrients taken up by the plant, not tissue concentration, is a better indicator of P-induced micronutrient An experiment was conducted to determine if orchid liners accumulate deficiency in the two cultivars of strawberry tested. silicon and if this element can affect seedling growth and development. A total of 800 liners were evaluated, by applying silicon (AgSil 25) as (165) Carotenoid Pigments in Kale Are Influenced a drench with three treatments (0.5%, 1.0%, and 2.0%) and a control (no Si fertilization). AgSil 25 affected the pH of the growing medium, by the Ratio of Calcium to Magnesium % Si content of the plant and overall development of Phalaenopsis David Kopsell* liners. Both pH and % Si increased significantly over the control Illinois State University, Normal, IL; [email protected] with increasing rates of AgSil 25. Silicon applied at 1% significantly Dean Kopsell increased whole plant dry weight, shoot fresh and dry weight, and The University of Tennessee, Knoxville, TN; [email protected] root dry weight over the control whereas at 0.5% only shoot fresh Sufficiency ranges for delivering essential elements to crop plant weight, root dry weight and root length were increased. Other plant are routinely used by producers to determine fertilizer applications. parameters evaluated, such as leaf number, leaf size, and chlorophyll, Because many production regions in the U.S. have very high or very were not affected by the application of silicon. The data obtained from low amounts of one or more essential nutrients, crop consultants this experiment demonstrated that Phalaenopsis orchid liners are ac- often use nutrient ratios as a means of ensuring sufficient root uptake cumulators of silicon, and that this element may influence their growth of competitive ions. Two essential nutrient cations which compete and development. Further studies are needed to address the beneficial for uptake are calcium (Ca) and magnesium (Mg). Kale (Brassica effects of Si fertilization on the lifecycle of Phalaenopsis up to flower- oleracea L. var. acephala D.C.) has been reported to accumulate high ing. Especially since important horticultural traits such as plant growth levels of carotenoids and these compounds serve antioxidant functions rate, size, flower initiation, development and quality could be enhanced in photosynthetic processes, as well as actions of disease reduction in by the uptake of silicon. In addition, the effects of silicon fertilization mammalian systems. The objectives of our research were determine on reducing abiotic (i.e. temperature, light and edema) and biotic (i.e. the influence of the ratio of Ca to Mg fertilization on the quality factors plant disease) stresses are warranted because of the potential positive of kale which include 1) biomass production, 2) chlorophyll content, impact for the orchid industry. and 3) accumulation of the important carotenoids for human health Specified Source(s) of Funding: Florida Nurserymen, Growers, and β-carotene and lutein. ‘Redbor’ kale was greenhouse-grown in nutri- Landscape Association ent culture using a modified Hoagland’s solution in Normal, IL and Knoxville, TN, in Fall 2008. The ratio of Ca:Mg was varied from 9:1, (164) Influence of Elevated Phosphorus Levels in 6:1, 3:1, 1:3, 1:6, and 1:9, respectively. Kale was seeded the first week Nutrient Solution on Micronutrient Uptake and of Sept. 2008 in both locations and 15 days later plants were transferred Deficiency Symptom Development in Strawberry to solution culture in a randomized block design with 4 replications. After six weeks plants reached a marketable size and were harvested. At Cultured with a Fertigation System harvest, fresh biomass was taken and leaf tissue samples were frozen at Jong Myung Choi -20 °C. Plant tissues were freeze-dried and carotenoid and chlorophyll Pai Chai University, Daejeon 302-735; [email protected] compounds were extracted and separated using HPLC. The ratio of Ca: Chiwon W. Lee* Mg significantly affected plant biomass, total carotenoids, β-carotene, North Dakota State University, Fargo, ND; [email protected] lutein, and chlorophyll b in leaf tissues. Carotenoid concentrations were

1118 HORTSCIENCE, VOL. 44(4), JULY 2009 within previously reported ranges. Total plant biomass decreased linearly The effect of mineral nutrient (fertilizer) and growing substrate source (P < 0.001) from 68.21 mg/plant under the 9:1 Ca:Mg treatment to on the yield of beetroot (Beta vulgaris ‘Bulls Blood’) was evaluated 21.86 mg/plant under the 1:9 Ca:Mg treatment. Total carotenoids also in a closed, nutrient recirculating ‘Nutrient Film Technique’ (NFT) decreased linearly (P = 0.04) from 20.13 mg/100 grams fresh weight hydroponic system. Seedlings raised in 1-inch oasis or rockwool cubes (gfw) under the 9:1 Ca:Mg treatment to 13.31 mg/100 gfw under the were transferred into rows (28 cm apart) of PVC Hydro-Troughs with 1:9 Ca:Mg treatment. The highest levels of the individual carotenoids 4.45 cm diameter holes at 20 cm spacing (along the row) at the one β-carotene and lutein were observed under the 3:1 Ca:Mg treatment true-leaf stage. Seedlings were grown until harvesting, either with Peters in each environment. These results indicate that producers wishing to Excel-CAL-MAG® (CAL-MAG; J. R. Peters, Inc., Allentown, PA), or maximize the carotenoid content of kale need to consider the ratio of All-Purpose Hydroponic Nutrient® (APHN; Hollister’s Hydroponics, Ca:Mg in their fertility programs. Grand Junction, CO), consisting of 15-5-15, and 9-4-15, respectively

as percent N-P2O5-K2O. Nitrogen (N) concentration in nutrient solution (166) Foliar Application of Nickel and Copper on was 200 mg/liter with CAL-MAG, and at manufacturer’s recommended Pecan Performance concentration (1 lb fertilizer/100 gallon of water [108 mg N/liter]) with Pradeep Wagle* APHN. CAL-MAG increased fresh and dry weight yield of beetroot Oklahoma State University, Stillwater, OK; [email protected] 2-3 fold compared with APHN. Fertilizer × substrate interaction was significant (P ≤ 0.05) for all the yield parameters measured except root POSTERS–Sunday Michael W. Smith dry weight (RDW) and root:leaf ratio (RLR). With CAL-MAG, com- Oklahoma State University, Stillwater, OK; [email protected] ponents of yield (except RDW and RLR) were increased significantly Bruce W. Wood (P ≤ 0.0003) in rockwool compared with oasis cube. However, with USDA–ARS, Byron, GA; [email protected] APHN, only leaf fresh weight was significantly higher (P = 0.0492) Charles T. Rohla in rockwool than oasis cube. While fertilizer had no effect on leaf total Samuel Roberts Noble Foundation, Ardmore, OK; [email protected] N and potassium, CAL-MAG significantly increased the concentration Charles C. Reilly of calcium (Ca), magnesium, and sulfur (P <0.0001; P = 0.0069 and P USDA–ARS, Byron, GA; [email protected] = 0.0246, respectively) over APHN, but phosphorus was significantly higher (P = 0.0403) with APHN. Of the micronutrients, leaf boron (B) The mobilization and conversion of reserve nitrogen (N) is critical and molybdenum (Mo) (P < 0.0001), as well as aluminum (Al; P = for pecans [Carya illinoinensis (Wang.) K. Koch] during early spring 0.0403) concentration varied significantly with fertilizer, and fertilizer when trees begin growing actively. Conversion of N reserves to trans- × substrate interaction was significant (P ≤ 0.05) for B and Al. With locatable forms (amides, amino acids, ureides) is adversely affected the exception of Ca and B (respectively, 66–75% and 52–72% below by a nickel (Ni) shortage. Nickel is required for urease (EC 3.5.1.5, the sufficiency range), leaf concentration of essential nutrients were urea amidohydrolase) activation and appears to function in additional sufficient for beetroot, regardless of fertilizer. These trends suggest enzymes affecting N metabolism. The orchard used for study received that tissue Ca and B concentration contributed to the observed yield an unusually high amount of N annually from nitrate contaminated response of beetroot in this study. irrigation water. High N induces copper (Cu) deficiency by inhibiting transport in plants. Copper, Ni and Ni + Cu were applied as a foliar Specified Source(s) of Funding: This work is supported by USDA- spray application at the parachute stage of leaf development (19 April), CSREES Grant No. MOX-HYDROPONICS-05. Lincoln University followed by two additional applications at two weeks intervals. Nickel of Missouri, Jefferson City, MO 65102. and Ni + Cu increased the weight per nut. Kernel percent and quality were not affected by treatment. Kernel necrosis, a malady characterized (168) Commercial Fertilizer Source Affects by necrotic tissue at the basal end of the kernel, was not affected by Marketable Leaf Yield of Collards in NFT treatment. Pecan kernels contain about 70% oil that is compartmentalized Hydroponic Culture in oil bodies. Leakage of these bodies into intercellular spaces, termed opalescence, affects appearance and reduces shelf-life. Treatments Jonathan N. Egilla increased opalescence compared to the control, perhaps the result of Lincoln University of Missouri, Jefferson City, MO; [email protected] increased oil content. The Ni + Cu treatment reduced yield and yield Rose Ogutu* efficiency; whereas, other treatments were similar to the control. Trunk Lincoln University of Missouri, Jefferson City, MO; OgutuR@lincolnu. growth and area per leaf were increased by Ni application, but specific edu leaf weight was unaffected. Leaf P, K, Ca, Mg, Fe, and Mn were not The effect of three commercial fertilizers on leaf yield of Collards affected by treatment, but Cu and Zn concentration of foliage and nuts (Brassica oleracea, Acephala group ‘Champion’) was evaluated in were affected. Results indicate that foliar Ni application was beneficial, a closed, nutrient recirculating “Nutrient Film Technique” (NFT) but Cu was not, in this particular orchard situation. Zinc sulfate was hydroponic system. Seedlings raised in 1-inch rockwool cubes were applied as a standard management practice to the control and was transferred into rows (28 cm apart) of PVC Hydro-Troughs with 4.45 combined with Ni, Cu, and Ni + Cu treatments. Results indicate the cm diameter holes at 20 cm spacing (along the row) at the first true- possibility that combining Zn, Ni and Cu in the foliar application may leaf stage. Seedlings were grown until harvesting, either with Peters reduce yield via either an excess salt-effect or by competitive inhibition Excel-CAL-MAG® (CAL-MAG), Peters Peat-Lite Special® (PLTE), of the timely physiological availability of a key nutrient. or Peters General-Purpose Soluble Fertilizer® (P-GP) containing 15- 5-15, 15-16-17 and 20-20-20, respectively, as percent N-P O -K O. Specified Source(s) of Funding: credit card 2 5 2 Nutrient solution from each fertilizer source was prepared to supply (167) Interaction Between Nutrient Source and nitrogen (N) at 200 mg/liter. At 64 days after transfer to NFT culture, Growing Substrate on the Yield of Beetroot in NFT the 77-day old Collards plants were root-pruned, and the fertilizer solutions renewed. Forty-two days after root pruning, marketable leaf Hydroponic Culture yield (young, fully expanded leaves) from the fertilizer treatments Jonathan Egilla* were compared. Significant differences were observed in leaf count, Lincoln University of Missouri, Jefferson City, MO; [email protected] leaf fresh and dry weight [CAL-MAG > (PLTE = P-GP)] and leaf dry

HORTSCIENCE, VOL. 44(4), JULY 2009 1119 weight ratio (CAL-MAG > PLTE > P-GP) (P = 0.01). Differences in [email protected] – petiole sap nutrient content was significant for NO3 N [PLTE > CAL- Maren J. Mochizuki* MAG (P = 0.01); and P-GP > CAL-MAG (P = 0.05)], and potassium Univ. of Calif. Cooperative Extension, Ventura, CA; [CAL-MAG > (PLTE = P-GP)] (P = 0.01). Petiole sap sodium content [email protected] also varied significantly with fertilizer treatment (CAL-MAG > P-GP Miguel Ahumada > PLTE) (P = 0.05), and [CAL-MAG > (P-GP = PLTE)] (P = 0.01). Driscoll’s Berry Associates, Inc., Camarillo, CA; miguel. – Petiole NO3 –N concentration indicates that N supply in nutrient so- [email protected] lution was not the yield-limiting factor in this study. CAL-MAG, the Shawn Ashkan only calcium (Ca)–supplying fertilizer of the three (38.3 mg Ca/liter), Calif. State University, Fresno, CA; [email protected] promoted greater marketable leaf yield than either PLTE or P-GP. Carol Lovatt Magnesium supply from CAL-MAG was 1.7 and 4-fold the amount Univ. of Calif., Riverside, CA; [email protected] from PLTE and P-GP, respectively.

Anthropogenic sources of carbon dioxide (CO2) released into the Specified Source(s) of Funding: This work is supported by USDA_CS- atmosphere may increasingly affect the global climate system. While REES Grant No. MOX-HYDROPONICS-05. Lincoln University of CO2 capture and sequestration is currently costly and underdeveloped, Missouri, Jefferson City, MO 65102. producers of high-value agricultural crops such as raspberry may be- come advocates for CO capture and recycling if substantive benefits (169) Growth and Inorganic Nutrient Absorption 2 to plants can be demonstrated. We designed a completely randomized of ‘Fuyu’ Persimmon Trees as Affected by Different study with three replications to optimize a CO2 application system to Fruit Loads field grown raspberry (proprietary variety) under high tunnels and to Seong-Tae Choi* compare plant photosynthesis, growth, and fruit yield with and without

Sweet Persimmon Res. Inst., Gimhae 621-802; [email protected] CO2. Leaves at the top of the canopy were 8% less efficient in using Seong-Mo Kang available light energy according to leaf fluorescence measurements Gyeongsang National University, Jinju 660-701; [email protected] so we placed the irrigation drip tape to apply CO2 in the middle of the plant canopy. We found that leaf CO assimilation and stomatal Doo-Sang Park 2 conductance were reduced 55% and 30% during the midday, and Sweet Persimmon Res. Inst., Gimhae 621-802; [email protected] therefore chose to apply CO from 7:00 to 11:00 am and from 2:00 Yong-Cho Cho 2 to 6:00 pm. In this way, we maintained a CO2 concentration of 436 Sweet Persimmon Res. Inst., Gimhae 621-802; choyo5259@gsnd. -1 μL·L for four months in tunnels 91.4 m long and 5.5 m wide. CO2 net concentration in the tunnel was 18% higher in the morning hours; wind This experiment was conducted to investigate growth and nutrient speed often increased in the afternoon, which may have moved the absorption of 3-year-old ‘Fuyu’ persimmon as affected by different CO2 even in the protected tunnel. In CO2 tunnels, yield and berry size levels of fruit load. The final leaf-to-fruit ratios of container-grown trees from plots 6 m long increased 12% and 5%, respectively, compared were adjusted to 10, 20, 30, and 60 on July 5. The higher the fruit load to untreated tunnels. The number of fruit baskets harvested from the the higher the yield, but the lower the fruit weight, soluble solids, and entire tunnel increased 36% after CO2 application when compared to fruit color. Dry weight of aerial woods and the root increased signifi- previous floricane yield in the same tunnels; the number of fruit baskets cantly with decreasing fruit load. However, total dry weight inclusive also increased 16% in untreated tunnels. We found no corresponding of the fruits was higher in the high than in the low fruit load trees; the differential response in leaf CO2 assimilation, stomatal conductance, weight of a tree that had maintained the ratio at 10 was higher by 22% and fluorescence, raspberry cane height, pruned cane biomass, cane compared with a tree with the ratio at 60. Fruits accounted for 48% of diameter, or carbohydrate content of the fruit after CO2 application; total dry weight when the ratio was 10, but 18% when the ratio was documenting plant physiological changes must be the focus of future 60. The amount of nutrients increased in tree parts were calculated by research. As the economic feasibility this system depends on a source subtracting the contents at the time of bud-break from those at the end of captured or recycled CO2, we hope this study prompts further of the season. On a tree basis, different fruit loads did not significantly research and development of CO2 capture and recycling to benefit affect the total amount of inorganic elements absorbed. As fruit load was agricultural producers. higher, however, the amount in the fruits amounted to 41%, 86%, and 69%, respectively, of the total uptake of N, P, and K when the leaf-fruit (111) Establishing Organic Highbush Blueberry ratio was 10. The result suggested the necessity for nutrient supply that Production Systems—The Effect of Raised Beds, should correspond with the level of fruit load since the nutrient in the Weed Management, Fertility, and Cultivar fruits are permanently removed from the tree. Handell Larco* Specified Source(s) of Funding: Rural Development Administration Oregon State University, Corvallis, OR; [email protected] in Korea Bernadine Strik Oregon State University, Corvallis, OR; [email protected] Horticultural Crops Culture and Management: David Bryla Viticulture and Small Fruit 2 USDA–ARS, Corvallis, OR; [email protected] Dan Sullivan Sunday, 26 July 2009 12:00–12:45 pm Oregon State University, Corvallis, OR; [email protected] A new research planting was established in Aurora, OR, in Oct. 2006 (110) Carbon Dioxide Enrichment Increases Yield of on a silt loam with a soil pH of 4.9 and 3.7% organic matter. Treat- Field-grown Red Raspberry Under High Tunnels ments included: cultivar (Duke or Liberty); planting on flat ground or Oleg Daugovish raised beds; fertilization with either fish emulsion or feather meal (at Univ. of Calif. Cooperative Extension, Ventura, CA; 25 or 50 kg/ha N); and weed management systems (sawdust mulch and hand weeding; compost plus sawdust mulch and use of flaming or

1120 HORTSCIENCE, VOL. 44(4), JULY 2009 acetic acid; and weed mat). The planting was certified organic in May location, antioxidant potential results were very similar when com- 2008. Data were collected through the first two years of establishment paring ‘Ouachita’ from Oklahoma and Arkansas. Oklahoma ‘Apache’ (2007 and 2008). In general, soil water content was lower through the showed higher total phenolics compared to Arkansas ‘Apache’, which season on raised beds than on flat ground, especially under weed mat had higher flavonoid and anthocyanin content than the Oklahoma (which increased soil temperature as much as 5 °C); this system thus ‘Apache’. Results of the sensory panel indicated blackberry cultivar required more irrigation water to maintain adequate soil moisture. had a significant effect on sweetness, acidity and flavor, but grow- Weed presence was not high in 2007, never exceeding 20% coverage. ing location was not significant when averaged over both cultivars. Weed mat plots had the fewest weeds whereas compost plus sawdust However, ‘Apache’ blackberries from Oklahoma were significantly mulched plots had the most in both years. Acetic acid, applied every 3 sweeter than ‘Apache’ berries from Arkansas while ‘Ouachita’ ber- weeks during the warmer months, worked well in 2007; flaming was ries from Arkansas had significantly greater ratings for sweetness and added in 2008, but hand weeding was still required in both years in acidity than ‘Ouachita’ from Oklahoma. When we compared results all treatments. In Oct. 2007, total plant dry weight (DW) was higher for sweetness, acidity and flavor of berries harvested in Oklahoma, in Liberty than Duke, raised beds than flat ground, and with fish emul- ‘Apache’ had significantly higher ratings than ‘Ouachita’. These results sion than with feather meal but was not affected by weed management should help growers decide which blackberry cultivars perform better system. Root DW was greater in Duke and lowest in plants receiving in their specific growing area, whether in Arkansas or Oklahoma. Ad- 50 kg/ha N as fish emulsion when grown under weed mat. In Oct. ditional evaluation is underway to help characterize the winemaking POSTERS–Sunday 2008, total plant DW was highest in Liberty and plants grown on raised potential of these cultivars. beds but was not affected by weed management or fertility. Root DW Specified Source(s) of Funding: North American Bramble Growers in Duke was not affected by planting on raised beds but was greater Research Foundation in plants grown with sawdust mulch and fertilized with 25 kg/ha N as fish. In Liberty, the greatest root DW was in plants with compost (113) Effect of Mounding Height and Mulching plus sawdust mulch and fertilized with 25 kg/ha N as fish, while leaf area was greatest in plants grown on raised beds with sawdust mulch Material on Growth and Fruiting of ‘Duke’ and 50 kg/ha N as fish. In 2008, yield was greater in Liberty than in Highbush Blueberry Plants Duke and on raised beds compared to flat ground, and fish fertilizer Eunju Kim* produced more yield than feather meal. Fruit firmness was affected Jeollabuk-do Agricultural Research and Extension Services, Iksan; by cultivar, mulch type, and raised bed production, whereas fruit size [email protected] was only affected by cultivar. Hyunggook Kim Jeollabuk-do Agricultural Research and Extension Services, Iksan; (112) Sensory, Health and Quality Evaluation of Two [email protected] Blackberry (Rubus subgenus Rubus) Cultivars from Kyudong Choi Arkansas and Oklahoma Jeollabuk-do Agricultural Research and Extension Services, Iksan; Richelle Stafne* [email protected] Oklahoma State University, Stillwater, OK; [email protected] Sunghee Guak William G. McGlynn Chonbuk National University, Jeonju; [email protected] Oklahoma State University, Stillwater, OK; [email protected] Two experiments were conducted with highbush ‘Duke’ blueberry Eric T. Stafne plants in Korea to determine the effect of (1) mounding or soil covering Oklahoma State University, Stillwater, OK; [email protected] and (2) mulching on growth and fruiting. For experiment 1, two-year Edralin A. Lucas old trees were transplanted in the field and then mounded with the Oklahoma State University, Stillwater, OK; [email protected] same field soil at 5, 10, 15, or 20 cm in height, and finally mulched with 15 cm of pine bark (PB). For experiment 2, the two-year old John R. Clark trees transplanted were mulched with either bark, black non-woven University of Arkansas, Fayetteville, AR; [email protected] fabric (BNWF), black shading screen (BSS) or black PE film (BPEF). Berries from two thornless, erect, blackberry (Rubus subgenus Rubus) The results of the experiment 1 showed that, when determined 3 cultivars, Apache and Ouachita were harvested in summer 2008 from years after planting, the cumulative number of suckers produced was the University of Arkansas Fruit Research Station in Clarksville, about 112% higher in the trees receiving 15 cm mounding compared Arkansas and a commercial berry farm in Broken Arrow, Oklahoma. to 5 cm mounding, with 20 cm mounding being less effective than Berries were frozen immediately after harvest for future analysis at 15 cm. Root to shoot ratio was highest in 15 cm, followed by 20 cm. Oklahoma State University, Stillwater. In Fall 2008 and Winter 2009, The number of flower clusters and total yield per tree was 128 and berries were analyzed for soluble solids, weights and dimensions, pH, 94% higher in 15 and 20 cm mounding treatments than 5 cm mound- titratable acidity (as citric acid), antioxidant potential (defined as total ing, respectively. Mean fruit weight, TSS, acidity and firmness were phenolic, flavonoid and anthocyanin content), and sensory attributes unaffected by the mounding height. The results of the experiment 2 (including seediness, juiciness, sweetness, acidity and flavor). Soluble showed that soil temperature was highest in BPEF while the other solids averaged 9.5% for ‘Ouachita’ from both locations and 10.5 mulching treatments had similar temperatures. Soil water content was and 10.2% for ‘Apache’ from Oklahoma and Arkansas, respectively. maintained the highest in BPEF, followed by BNWF, PB and BSS. Mean berry weight (g) was 2.8 for Oklahoma ‘Ouachita’, 4.2 for Ar- Determined two years after planting, tree growth was best in BPEF kansas ‘Ouachita’, 4.8 for Oklahoma ‘Apache’, and 5.8 for Arkansas while lowest in BSS. The number of fruit set was similar among PB, ‘Apache’. Blackberry juice pH showed similar results, with Oklahoma BNWF and BPEF, which was significantly higher than BSS. Mean ‘Ouachita’ pH of 3.7 and 3.1pH for all others. Titratable acidity (%) fruit weight and fruit quality were not significantly affected. Yield for Oklahoma berries was 1.48 for ‘Ouachita’ and 1.12 for ‘Apache’, was similarly higher in PB and BNWF than BPEF and BSS, with and 1.38 for ‘Ouachita’ and 1.28 for ‘Apache’ from Arkansas berries. BSS showing the lowest yield. Some freezing injury was observed Comparing overall antioxidant potential, ‘Ouachita’ berries had lower from the current year’s shoots of the trees mulched with BPEF where content for phenolics and anthocyanins as compared to ‘Apache’. By growth termination was delayed.

HORTSCIENCE, VOL. 44(4), JULY 2009 1121 (114) Effect of Peat Moss-based Organic Material the commercially available primocane fruiting cultivars Prime-Jim® ® Mixtures on Soil pH, Growth and Fruit Quality of and Prime-Jan , and the floricane fruiting cultivar Chickasaw were established at the Kentucky State University Research Farm. In 2007 Highbush Blueberry Plants and 2008, primocane fruit production was evaluated for primocane Eunju Kim* fruiting selections. Frost damage limited floricane fruit production in Jeollabuk-do Agricultural Research and Extension Services, Iksan; the 2007 season. In 2007, the selection APF-40 had the greatest yield [email protected] (2598 lbs/acre) with Prime-Jim® displaying the smallest yield (295 lbs/ Hyunggook Kim acre). Berry weight was significantly larger for the selections APF-40 Jeollabuk-do Agricultural Research and Extension Services, Iksan; and APF-41 (about 3.9 grams/berry) than all other selections. In June [email protected] of 2008, APF-41 and APF-77 produced the largest floricane crops of Namki Oh 4415 and 3717 lbs/acre, respectively, and APF-46 the smallest floricane Jeollabuk-do Agricultural Research and Extension Services, Iksan; crop (672 lbs/acre). For the floricane crop, APF-41 and APF-40 had [email protected] the largest berries of all selections at 6.2 g and 5.0 g, respectively. The Sunghee Guak 2008 primocane crop began ripening in August. APF-27 had the largest Chonbuk National University, Jeonju; [email protected] primocane crop in 2008 (3005 lbs/acre); this selection had an almost 2-fold increase in the yield of the previous year. Primocane produc- These three consecutive year studies were conducted to evaluate the tion from APF-77 (2229 lbs/acre) also increased almost 2-fold in yield mixed use of peat moss (PM) with other organic material such as pine compared to the previous year’s primocane crop. Although APF-41 needle (PN), rice husk (RH) and sawdust (SD) for blueberry produc- had a large floricane crop in 2008, the primocane crop was only about tion in Korea, as a way to cut down the production cost due to the one-quarter the size of the floricane crop and was about 60% that of relatively expensive PM that is totally imported to Korea. In Spring the 2007 primocane crop. Primocane fruit of APF-41 were still large in 2006, two-year old ‘Duke’ blueberry nursery plants were transplanted size, but the primocane fruit of this selection were only 4.4 g on aver- into the field soil. In root zone, the following PM-based organic mate- age compared to the 6.2 g on average for floricanes in 2008. Even with rial mixtures were incorporated: 20 L PM only, 10 L PM + 10 L PN, irrigation, summer drought conditions may have negatively impacted 10 L PM + 10 L RH and 10 L PM + 10 L SD. Before planting, 1000 the primocane crop of all selections this year. Chickasaw had a larger kg cow manure, 160 kg sulfur and 20 kg compound fertilizer (N-P-K: yield than the primocane fruiting selections (8259 lbs/acre) and a large 30-25-25) per 10a were incorporated into the soil, then rotary-tilled. berry size (5.4 grams/berry). While some advanced selections appear Soil pH measured right after planting ranged from 5.3 to 5.9 and was superior to Prime-Jim® and Prime-Jan®, additional evaluations will be lower in PM only and PM + PN than PM + RH and SD treatments. In needed before decisions are made on whether any APF selections will the third year, the pH lowered to the range of 4.2 to 4.5, with PM only be released by the University of Arkansas. and PM + PN still maintaining lower values. Vegetative growth was maintained better in PM only and PM + PN, and the number of flower Specified Source(s) of Funding: Evans-Allen cluster and yield were also slightly higher in those treatments while mean fruit weight was similar among all treatments. Fruit quality was (116) BLUE FORMOSA—A Blueberry Initiative unaffected as total soluble solid, titratable acidity and firmness were Program in Taiwan measured. These results suggest that relatively cheaper organic mate- Kuo-Tan Li* rial such as PN, RH and SD may relieve in part the total dependence National Taiwan University, Taipei 10617; [email protected] of blueberry production in Korea on the PM and thus cut down the Blueberries were first introduced to Taiwan some 30 years ago. However, production cost. due to the high chilling requirement of these old northern highbush (115) Primocane and Floricane Yield type plants, it was thought that blueberries can only be grown in the Characteristics of Primocane Fruiting high elevated mountain areas in Taiwan’s tropical climate; hence the cultivation of blueberries has been limited. In 2007, BLUE FORMOSA, Blackberries from the University of Arkansas the first ever academic blueberry project in Taiwan was initiated by Breeding Program Grown in Kentucky National Taiwan University’s Fruit Crop Physiology Laboratory. The Jeremiah Lowe* mission of BLUE FORMOSA is to conduct scientific research and Kentucky State University, Frankfort, KY; [email protected] introduction of blueberry production to Taiwan as well as to provide Kirk Pomper an information platform to potential growers and enterprises. BLUE FORMOSA specifically interests in the potential of low chill rabbiteye Kentucky State University, Frankfort, KY; [email protected] and southern highbush cultivars in subtropical and tropical climates. Sheri Crabtree Currently 32 cultivars are under evaluation. Test trails were initiated at Kentucky State University, Frankfort, KY; [email protected] low, middle, and high altitudes in Northern and Central Taiwan. We have John R. Clark also obtained 70 open pollination seedlings from northern highbush and University of Arkansas, Fayetteville, AR; [email protected] >100 op seedlings from rabbiteye and southern highbush for breeding John Strang evaluation. The preliminary results indicated that most cultivars, regard- University of Kentucky, Lexington, KY; [email protected] less of their parentage, can thrive in the summer heat and humidity in lowland Taiwan. Although the winter temperature appeared insufficient Primocane fruiting blackberries have the potential to produce a niche- market crop for Kentucky growers from late summer until frost. The for most cultivars for their recommended chilling requirement, many cultivars bloomed and set fruit on current year suckers in late fall and objective of this study was to determine if advanced selections devel- early winter. This result opens the possibility of off-season blueberry oped by the University of Arkansas Blackberry Breeding Program were ® ® production in tropics. Future research for BLUE FORMOSA includes superior to Prime-Jim and Prime-Jan in terms of yield and fruit size techniques to improve multiplication rate by greenwood and hardwood under Kentucky growing conditions. In June 2006, six selections of cuttings, breeding for low chill cultivars, and cultivar practices for primocane fruiting blackberries from the University of Arkansas breed- successful off-season berry production. ing program (APF-27, APF-40, APF-41, APF-42, APF-46, and APF-77),

1122 HORTSCIENCE, VOL. 44(4), JULY 2009 With recent concern for preserving natural resources, use of drought- Undergraduate Poster Session and tolerant ornamentals may become a valuable method of lowering water Competition - Session 1 usage for homeowners. The mostly herbaceous perennial Penstemon genus offers drought-tolerance, some level of acceptance in urban land- Sunday, 26 July 2009 12:00–1:00 pm scape and an enormous amount of genetic diversity. With around 280 different species, Penstemon is among the largest genera of herbaceous Note: You must stay with your poster for the full session time perennials native to North America. Chemical mutagenesis with EMS has been used to induce novel phenotypes in a vast number of crops period. both agronomic and ornamental. This mutagen may prove to be a valu- able tool in helping to further domesticate Penstemon for use in urban (1) Effect of Vine Cutback on Symptom Severity landscaping. The scope of this research is to identify the phenotypic and Virus Titers of a Resistant and Susceptible effects of EMS on several different species of Penstemon. In preliminary tests, we have treated Penstemon strictus with concentrations ranging Sweetpotato Variety from 0.025% to 3% EMS. These concentrations have already shown a Carly Gillette* wide array of mutations in the juvenile vegetative growth. Among the LSU AgCenter, Barton Rouge, LA; [email protected] surviving plants treated with 0.675% EMS, common mutations include: POSTERS–Sunday Maureen Thiessen dwarfing (32%), fused leaves (11%), and variegation in the leaf tissue LSU AgCenter, Barton Rouge, LA; [email protected] (1%). Since Penstemon are often clonally propagated, these induced Don LaBonte mutations, along with the natural beauty and diversity of Penstemon, LSU AgCenter, Barton Rouge, LA; [email protected] may produce superior cultivars which are economically beneficial and environmentally friendly. Chris Clark LSU AgCenter, Baton Rouge, LA; [email protected] Specified Source(s) of Funding: Brigham Young University Cecilia McGregor UGA, Athens, GA; [email protected] (3) Molecular Mapping of the Tomato Spotted Wilt Virus Resistance Gene Sw-7 in Tomato The most important virus disease in sweetpotato is Sweetpotato virus disease (SPVD), a result of co-infection of Sweetpotato chlorotic stunt Keri G. Dockter* virus (SPCSV) and Sweetpotato feathery mottle virus (SPFMV). Charac- Brigham Young University, Provo, UT; [email protected] teristic symptoms include chlorosis, small, deformed leaves, and severe Derek S. O’Neil stunting. Yield reductions of up to 90% have been reported in SPVD Brigham Young University, Provo, UT; [email protected] affected plants. Our objective was to compare symptom development David L. Price and the pattern of accumulation of the two viruses in mixed infections Brigham Young University, Provo, UT; [email protected] in an SPVD resistant (NASPOT 1) and susceptible (Beauregard) variety John Scott in plants cut back and allowed to regrow from axillary buds. Typical GCREC, Wimauma, FL; jwsc@ufl.edu symptoms developed on graft-inoculated Beauregard after nearly one Mikel R. Stevens month of growth in the greenhouse while symptom development on Brigham Young University, Provo, UT; [email protected] NASPOT 1 was minimal at this time. Half the plants of each variety were then cut back and all plants were allowed to reproliferate for Tomato spotted wilt virus (TSWV), vectored by several thrips spe- an additional month. Virus symptoms developed on both varieties of cies, is the causal agent of devastating tomato crop losses in many plants that were cut back but not on NASPOT 1 plants that were not areas of the world. Recently, field tests have demonstrated that there cut back. Leaves were collected from all plants for analyses of virus are TSWV isolates that overcome the resistance gene Sw-5, derived titers using real-time PCR. from Lycopersicon peruvianum L. However, Sw-7, a new source of TSWV resistance, has been introgressed from L. chilense Dun. This (2) Early Phenotypic Mutation Results Induced new gene has demonstrated field resistance to various isolates of this by Ethyl Methyl Sulfonate (EMS) on Species of disease including greenhouse trials utilizing isolates that overcome Penstemon Sw-5. In order to determine the genetic location of Sw-7, we screened over 200 SSR and InDel molecular markers from across the tomato Rhyan B. Dockter* genome. We used the homozygous (Sw-7/Sw-7) Ck12 line and one of Brigham Young University, Provo, UT; [email protected] the susceptible (Sw-7+/ Sw-7+) recurrent backcross parents (Fla 7482B) Shaun R. Broderick along with six BC1 and F2 plants segregating for Sw-7. The results of Brigham Young University, Provo, UT; [email protected] this screening suggested that Sw-7 resided near SSR20 on chromosome James D. Daley 12. To confirm the linkage of Sw-7 and SSR20 we tested this SSR

Brigham Young University, Provo, UT; [email protected] marker and others on chromosome 12 using 94 BC1 and F2 progeny Shawna L. Daley segregating for Sw-7. Additionally, we screened 47 lines segregating Brigham Young University, Provo, UT; [email protected] for Sw-7 under high natural TSWV field pressure conditions in northern Mitchell A. Mendenhall Florida. As a result of these studies we have narrowed the location of Brigham Young University, Provo, UT; [email protected] the L. chilense-derived DNA with Sw-7. This region resides between markers T1263 (45.0 cM) and SSR20 (58.2 cM), according to the Bryson J. Ewell “Tomato EXPEN-2000” map found on the Sol Genomics Network. Brigham Young University, Provo, UT; [email protected] Our efforts are now focused on determining the precise position of Brad Geary Sw-7 in relationship with the markers available in this region and the Brigham Young University, Provo, UT; [email protected] AFLP markers previously reported. Mikel Stevens Brigham Young University, Provo, UT; [email protected] Specified Source(s) of Funding: Brigham Young University

HORTSCIENCE, VOL. 44(4), JULY 2009 1123 (5) Photosynthetic, Antioxidant, and Leaf Arnulfo Marquez-Cervantes Ultrastructural Responses to Drought in Two INIFAP, Hermosillo Sonora; [email protected] Spinach Cultivars of Contrasting Morphology Gerardo Martinez Diaz INIFAP, Hermosillo Sonora; [email protected] Ronald Cherubin* Xavier University of Louisiana, New Orleans, LA; [email protected] In the Northwest of Mexico pecan vivipary levels are high. The goal of this study was to determine the effect of harvesting date, cultivar, Tommy Do and nut filling on vivipary of pecan trees growing in warm climate. Xavier University of Louisiana, New Orleans, LA; [email protected] Weather conditions during nut filling are: average high temperatures, Kanniah Rajasekaran 36.4 °C to 38.6 °C; average minimum temperatures, 15.0 °C to 26.8 USDA–ARS, New Orleans, LA; [email protected] °C; and average relative humidity, 47% to 69%. Harvest date effect on Dalton Gossett vivipary was obtained from a commercial harvest data during 2003 of Louisiana State University at Shreveport, Shreveport, LA; a cleaning plant. Vivipary was classified as “sprout” when the embryo [email protected] activity was big enough that nut shell split occurred at the apex, and Harish Ratnayaka as “embryo rot” when this activity just caused change in color and Xavier University of Louisiana, New Orleans, LA; [email protected] flavor of embryo. Harvest period analyzed was from October 9 through December 4. ‘Wichita’ sprouts varied from 11.9 to 24.1%. The steepest Understanding leaf physiological and structural responses to drought is increment occurred from October 9 to October 23. ‘Western’ had lower essential for developing drought resistant crops and maximizing water sprout level (9.5 to 15.1%). Embryo rot changed from 3.1 to 9.4% in use efficiency in agroecosystems worldwide. A greenhouse experi- ‘Wichita’ and from 8.4 to 13.6% in ‘Western’. Average levels of vivipary ment was conducted to evaluate drought acclimation of gas exchange, were also recorded during three years. In these years of study, sprout photosystem II function, antioxidant properties and leaf ultrastructure was higher in ‘Wichita’ (23.4%, 19.9%, and 19.8%) than in ‘Western’ of two spinach cultivars with contrasting morphology, Bloomsdale (13.5%, 13.9%, and 10.9%). Embryo rot was higher in ‘Western’ (20.2%, (larger leaves and stature) and Hybrid Tyee. Time to severe wilting -2 -1 5.5%, and 10.8%) than ‘Wichita’ (12.6%, 3.1%, 6.3%). Relationship that decreased net photosynthesis (P ) to <2 µmol·m ·s in half of the net between nut filling and sprout and embryo rot was not significant in replications during a progressive drought was 10 days in Bloomsdale ‘Western’ but in ‘Wichita’ a negative relationship was found for sprout but 16 days in Tyee. Four days after rewatering upon completion of r2 r2 progressive drought, leaf biomass had decreased 22% in Bloomsdale ( = 0.53*) and embryo rot ( = 0.79**). Cultivars, year of harvest, and 29% in Tyee, compared with respective well-watered controls. At and date of harvest influenced commercial nut quality of pecan trees growing under warm climate. Nut filling affected nut vivipary. wilting, stomatal conductance (gs) and transpiration (E) were 83% and 141% greater in Bloomsdale than Tyee, respectively. Photosystem II Specified Source(s) of Funding: Instituto Nacional de Investigaciones efficiency and electron transport rate were 16% and 32% greater in Forestales Agricolas y Pecuarias Bloomsdale at wilting. ACi curve analysis revealed that maximum

Rubisco carboxylation efficiency (Vcmax) and RuBP regeneration capacity (56) Effect of Compost Socks System on Antioxidant (Jmax) of well-watered Bloomsdale plants were 22% and 34% greater, Capacity, Flavonoid Content, and Fruit Quality of respectively, but CO compensation point (CCP) was 22% less than 2 Strawberries Tyee. A severely wilted Bloomsdale plant had 100%, and 70% greater Shiow Wang* Vcmax and Jmax, respectively, but with a 44% higher CCP compared with Tyee. Furthermore, severe drought stress caused 52% increase in CCP USDA–ARS, Beltsville, MD; [email protected] in Bloomsdale but 18% decrease in Tyee, probably indicating greater Patricia Millner dependence of Bloomsdale on photorespiration as an electron sink than USDA–ARS, Beltsville, MD; [email protected] Tyee under stress. Although gas exchange characteristics including Pnet The effect of cultivation practices on fruit quality, antioxidant capac- were still greater in Bloomsdale than Tyee one day after rewatering, both ity, and flavonoid content in strawberries var. Allstar and Chandler cultivars had the same gas exchange on the fourth day of rewatering. (Fragaria ×ananassa Duch.) was evaluated. Strawberry fruit used in While leaf ultrastructural and antioxidant investigations are currently this study were from plants grown in soils which had prior history of underway, the choice between Bloomsdale and Tyee under drought black root rot and red stele, caused by Phytophthora fragariae Hick- appears to warrant considerations of the intensity of water stress. Tyee man, and had not been fumigated during the seven years prior to the is more likely to withstand a prolonged drought causing severe wilting study. Results from this study showed that different cultural systems than Bloomsdale. (matted row, black plastic mulch and compost socks) significantly af- Specified Source(s) of Funding: Xavier University of Louisiana fected total anthocyanins and total phenolics in strawberries. Fruit from plants grown in compost socks had significantly higher oxygen radical absorbance capacity than fruit from black plastic mulch or matted row systems. Individual flavonoids and anthocyanins were also higher in Crop Physiology/Physiology: strawberries grown in compost socks than those grown in black plastic mulch or matted row systems. Higher levels of ellagic acid, ellagic acid Cross Commodity 2 glucoside, p-coumaroyl-glucose, quercetin 3-glucoside and quercetin Sunday 26 July 2009 1:15–2:00 pm 3-glucuronide, kaempferol 3-glucoside and kaempferol 3-glucuronide were also found in fruit grown from compost sock than those from other (55) Harvest Date, Cultivar, and Nut Filling on systems. Strawberry plants grown in compost socks also produce fruit with significantly higher soluble solids content, titratable acid, total Vivipary Levels of Pecan Trees Growing in Warm sugars, fructose, glucose, sucrose, and citric acid than fruits produced Climate in Northwest Mexico in the two other culture systems. In general, cv. Chandler surpassed Humberto Nunez* cv. Allstar in content of sugars, acids and flavonoids regardless of pre- University of Arizona, Tucson, AZ; [email protected] planting vinegar drenching and various culture treatments. However, pre-planting vinegar treatment increased acidity, and cyanidin-based

1124 HORTSCIENCE, VOL. 44(4), JULY 2009 and pelargonidin-based anthocyanins, but decreased sugar content in LD) photoperiod. All three genotypes produced more flowers under fruit of both cultivars. LD than SD at 14 and 17 ºC. ‘Tribute’ produced more flowers under LD than SD, regardless of temperature. ‘Honeoye’ produced more Specified Source(s) of Funding: USDA flowers under SD than LD under temperatures of 20 to 26 ºC, but did (57) Physicochemical Characteristics of Strawberry not flower under either photoperiod at 29 ºC. ‘Honeoye’ and RH 30 exhibited similar flowering patterns in response to temperature, with RH Fruits as Affected by Cultivar and Fruit Cluster 30 producing flowers at temperatures 3 ºC warmer than the threshold Sung Kyeom Kim temperature for flowering in ‘Honeoye’, regardless of photoperiod. Seoul National University, Seoul; [email protected] ‘Tribute’ continued to produce flowers under all treatments except 29 Ro Na Bae ºC under SD. Runner production was photoperiod and temperature Seoul National University, Seoul; [email protected] sensitive. ‘Honeoye’ and ‘Tribute’ only produced runners under LD, Moo Jung Kim with most runner formation occurring at ≥23 ºC for all genotypes. Our Seoul National University, Seoul; [email protected] results suggest that the term day-neutral does not accurately describe Jeong Hwa Song repeat flowering of strawberry. We propose that the term remontant Seoul National University, Seoul; [email protected] replace day-neutral to describe strawberry genotypes producing mul- tiple flowering cycles in a season and that this response is primarily POSTERS–Sunday Changhoo Chun* regulated by temperature. Seoul National University, Seoul; [email protected] Specified Source(s) of Funding: Private; State; HATCH ‘Maehyang’, ‘Seolhyang’, and ‘Keumhyang’, the recently bred Korean domestic cultivars and ‘Tochiotome’, one of major Japanese cultivars (59) Ecophysiology and Comparative Foliar were cultivated from September to May in a greenhouse. Ripen fruits in the 1st, 2nd, and 3rd fruit clusters (FCs) were sampled once a month Micromorphology of Big-Bracted Cornus Selections from January 16, 2007, to investigate their physicochemical character- Amy Fulcher* istics. Fresh weights of ‘Seolhyang’ and ‘Keumhyang’ fruits in the 1st University of Kentucky, Lexington, KY; [email protected] and 2nd FCs were higher than those of other cultivars, while that of Robert Geneve ‘Tochiotome’ was the greatest in the 3rd FC. Shape of ‘Maehyang’ and University of Kentucky, Lexington, KY; [email protected] ‘Keumhyang’ fruits was conical showing the ratio of length to diameter The most common Cornus taxa in the nursery industry are those from about 1.5, whereas that of ‘Seolhyang’ and ‘Tochiotome’ was about 1.3. the big-bracted tribe. Within this group a substantial amount of varia- Hue values of ‘Maehyang’ and ‘Keumhyang’ were lower than those of tion in environmental tolerances has been reported. Our objectives other cultivars in all the FCs. Firmness of all the cultivars decreased were 1) to determine the variation in a suite of foliar micromorphology as the FC increased and that of ‘Seolhyang’ was lowest in all the FCs. parameters and gas exchange for seedlings of C. kousa and C. florida Total carbohydrates content and total organic acids content of all the grown under controlled environment conditions and for three related tested cultivars in all the FCs was not significantly different. Contents grafted selections: C. florida ‘Cherokee Princess’, C. kousa ‘National’ of anthocyanin (AC) and ellagic acid (EA) were greatest in ‘Keum- and C. florida × C. kousa hybrid Constellation® grown in outdoor con- hyang’ and ‘Tochiotome’, respectively, in all the FCs, and contents of ditions, and 2) to determine variation in stomatal number for a range AC and EA increased as the FC increased. Content of ascorbic acid of eight established big-bracted selections, and a C. mas selection for was greatest in ‘Maehyang’ in all the FCs, and that in the 2nd FC was comparison, in order to better understand their response to stresses and greater than those in the 1st and the 3rd FCs in all the cultivars. Results performance in landscapes. Of the controlled-environment produced- indicate that the tested cultivars adapted to forced cultivation showed plants, the number of stomates per unit area was 60% greater for C. the better physical characteristics of fruits in the earlier FCs, while the florida than for C. kousa, 83.5 and 51.5, respectively. However, area contents of antioxidant phytochemicals were greater in the fruits in the per individual stomate and total stomatal area per leaf, an integrated later FCs. Results also suggest that the recently bred Korean cultivars value of stomate number and stomatal complex area, were greater for are comparative to major Japanese cultivars broadly cultivated in East C. kousa. Epidermal cell thickness was greater for C. kousa than C. Asian countries. florida. The pattern of wax deposition on the abaxial surface differed (58) Temperature Tolerance, Not Photoperiod between C. kousa and C. florida. The reduced total stomatal area per leaf and abaxial wax may be an adaptation to protect C. florida, which Insensitivity, Is the Primary Factor Controlling is considered drought-adverse. The number of stomates per unit leaf Repeat Flowering (Remontancy) in Strawberry area varied significantly among the established big-bracted selections Emma Bradford* from a low of 51.8 for C. mas ‘Spring Sun’ to a high of 209.6 for C. × Michigan State University, East Lansing, MI; [email protected] Constellation®. In general, the C. kousa cultivars and the C. kousa × James Hancock C. florida hybrids had a greater number of stomates per unit leaf area Michigan State University, East Lansing, MI; [email protected] than did C. mas ‘Spring Sun’ and C. kousa seedlings. The hybrids had a range of stomates, from 209.6 to 72.8 for Constellation® and Ruth Ryan Warner Ellen®, respectively. Among Constellation®, ‘Cherokee Princess’ and Michigan State University, East Lansing, MI; [email protected] ‘National’, Constellation® had the greatest number of stomates. The Fragaria ×ananassa Duch. ex Rozier (strawberry) cultivars are tradi- average stomatal complex size and average total stomatal area were tionally classified as short-day (Junebearing), day-neutral, or long-day greater for Constellation® and National than for ‘Cherokee Princess’. (everbearing) plants based on when and how often flowering occurs Constellation® had greater photosynthetic rate, stomatal conductance, during the growing season. Temperature is also known to influence and transpiration rates than both C. kousa ‘National’ and C. florida flowering in strawberry. To more clearly define the roles of temperature ‘Cherokee Princess’. Among the two species growing the controlled and day length in flowering control of strawberry, the short-day cultivar environment, C. florida had a greater photosynthetic rate, stomatal ‘Honeoye’, and two repeat flowering genotypes, ‘Tribute’ and an elite conductance, and transpiration rate than C. kousa. clone of Fragaria virginiana Mill. ssp. virginiana, RH 30, were grown at 14 ,17, 20, 23, 26, or 29 °C, under a short (9 hr; SD) or long (16 hr; Specified Source(s) of Funding: New Crop Opportunities Center

HORTSCIENCE, VOL. 44(4), JULY 2009 1125 (60) Developing a Carbon Balance Model for were the principal source of labile K and P for developing fruit. A rapid ‘Kyoho’ Table Grapes Under Double Cropping accumulation of K in the fruit with a concurrent loss from leaves started in July when fruit began a rapid volume increase that continued during Production System in Subtropical Climate carbohydrate deposition in the cotyledon. At first detectable shuck split Ben-Min Chang* K transported to the fruit ceased, but leaf K was partially replenished National Taiwan University, Taipei 10617; [email protected] between shuck split and defoliation, presumably from K in perennial Kuo-Tan Li tissue since total tree K was static or decreased slightly. In contrast, National Taiwan University, Taipei 10617; [email protected] rapid P transport to fruit began after fruit expansion while cotyledons Alan Lakso were developing, presumably associated with oil synthesis and after Cornell University, Geneva, NY; [email protected] initial shuck split for storage. Leaf P content continued to decline until Tzong-Shyan Li leaves were killed by freezing temperatures in the fall. National Taiwan University, Taipei 10617; [email protected] Specified Source(s) of Funding: credit card To develop a carbon balance model for grapevines in Taiwan’s sub- (62) Broccoli Cytochrome P450 Genes Associated tropical climate, we adopted the basic structure of ‘Vitisim’, a model designed for wine grapes in New York. Climatic inputs and growth with Indole Glucosinolate Biosynthesis parameters were then adjusted and compared using data collected in a Hyoung Seok Kim commercial vineyard from the beginning of the second cropping sea- University of Illinois, Urbana-Champaign, Urbana, IL; hkim58@illinois. son in 2008. Canopy development and canopy light interception were edu measured on mature ‘Kyoho’ table grapevines (Vitis vinifera L. x V. John A. Juvik* labrusca L.) trained with an overhead horizontal trellis. Selected buds University of Illinois, Urbana-Champaign, Urbana, IL; [email protected] for winter crops were forced on late August after the first harvest. Shoot Brassica oleracea Italica and berry development in the second cropping season were therefore Broccoli ( L. ssp.. ) is a rich source of indolyl glucosinolates (glucobrassicin and neoglucobrassicin), phytochemicals under the gradual shortened day length and decreased temperature, that are hydrolyzed into isothiocyanates with known anti-carcinogenic in contrast to the first cropping or vines in temperate regions. Day -1 bioactivity. Information on glucosinolate metabolism in crucifer plant length during the second cropping season decreased from 44760 s.d -1 species is incomplete in its understanding of how glucosinolates accu at bud break to 38220 s.d at harvest, in comparison to 41500-54000 - -1 -1 -1 mulate, and how they are transported and undergo catabolic degradation s.d in New York, 46140-56568 s.d in Italy, and 43620-49140 s.d in during the plant’s life cycle. The dramatic increase in the amounts of the first cropping season in Taiwan. Average daily radiation was also . - these indolyl glucosinolates in broccoli induced in response to treat lower in the second cropping season in central Taiwan (10.79 MJ m - 2 -1 . -2 -1 ments with methyl jasmonate (MeJA) provides a system to investigate .d ) than that in the first cropping season (16.13 MJ m .d ) and that . -2 -1 the synthesis and flux of glucosinolates and associated changes in gene in the normal growing season in New York (16.03 MJ m .d ). There was no difference among the first cropping season, the second crop- expression patterns. Genes involved with the biosynthesis of gluco- CYP79B2, CYP79F1, CYP83A1 CYP83B1 ping season, and the N.Y. growing season on heat accumulation from sinolates ( and ) were isolated Arabidopsis bud break to full bloom based on 10 °C, but the heat accumulation from broccoli using primer sets based on sequences, which Arabidopsis from bud break to harvest for the second cropping season in Taiwan averaged 88 % sequence homology with corresponding was 1450 degree days, slightly longer than 1393 degree days in N.Y. transcripts. Expression levels of these and two other genes (myrosinase Maximum canopy light interception for grapevines trained with the and epithiospecifier protein), involved in the hydrolysis of glucosino- horizontal trellis system in Taiwan was 41%, similar to that of vines lates, were analyzed in different broccoli plant tissues (leaf, stem and trained with a hedge row trellis in N.Y. In the second cropping season immature florets) at two different developmental stages by quantitative leaf fall began 108 days after bud break, sooner than that of 160 days in RT-PCR. Glucosinolate concentrations were also profiled in the same N.Y. Gas exchange parameters of ‘Kyoho’ grapevines were measured tissues with or without MeJA treatment to determine correlations between on potted vines. Maximum photosynthesis rate of ‘Kyoho’ grapevines metabolite profiling and gene expression data. Expression levels of the -2 -1 four broccoli P450 genes differentially responded to MeJA treatment was 14.5 μmol·m ·s . In early Oct. 2008 a tropical storm (typhoon) with upregulation of BoCYP79B2 BoCYP83A1 partially defoliated the vines and temporary reduced LAI by 67%. and correlating with Our model simulation indicated that this typhoon damage might have increased indolyl glucosinolate concentrations in broccoli tissues. This suggests that these two genes may play a key role in regulating indoyl reduced total seasonal fixed CO2 by 7.1%. By leaf fall, 724 g. CO2 per square meter of the vineyard were fixed in the second cropping season glucosinolate accumulation in broccoli tissues. in Taiwan, less than 1583 g CO in N.Y. 2 (63) Cucumber Fruit Transcriptome Analysis (61) Partitioning of Phosphorous and Potassium in by 454 Sequencing Pecan Trees in Relation to Annual Crop Intensity Kaori Ando* Michael W. Smith* Michigan State University, East Lansing, MI; [email protected] Oklahoma State University, Stillwater, OK; [email protected] Rebecca Grumet Michigan State University, East Lansing, MI; [email protected] Potassium (K) and phosphorus (P) partitioning were characterized in bearing pecan [Carya illinoinensis (Wangenh.) K. Koch] trees at selected Cucumber mRNA samples from fruit tissue at 8 days post pollination times of the year during successive three years. The first year trees had (dpp), were subjected to 454-sequencing. These analyses yielded 187,406 little to no crop, followed by a small crop and a near optimal to excess clean reads, of which 88% could be assembled into 13,879 contigs, crop during the third year. Trees bearing a commercial crop accumulated 52–2824 nt in length. The number of sequences per contig, which is more K and P in July than trees with little or no crop. Potassium and reflective of transcript abundance, ranged from 2–5167. BLAST analysis P content in trees increased from budbreak until July then decreased of the most highly represented transcripts (71 contig groups showing > until budbreak the following year. Allocation patterns of K and P among 0.15 % frequency in the transcript pool) against the nr protein sequence tree components changed during the growing season with the greatest NCBI database, indicated high representation of genes associated with changes occurring in the annual plant parts. Results indicate that leaves protein synthesis, flowers, fruits or seeds of other species, latex related

1126 HORTSCIENCE, VOL. 44(4), JULY 2009 proteins, lipid biosynthesis, cell expansion, defense, phloem transport, Watermelon grafting is an important part of watermelon production and photosynthesis. Approximately 10 % of the highly abundant tran- in areas where land rotation is not possible, to avoid soil borne dis- scripts did not have a match in the NCBI in the nr protein database, eases and/or to avoid chemical fumigation. Graft survival depends on suggesting that these genes could be unique to cucumber fruit. The 126 maintaining at least one rootstock cotyledon during the healing period most highly expressed contigs (0.9 % of total contigs) accounted for following grafting. One purpose of the cotyledon is to supply necessary 36.8% of total reads. The most frequently expressed contig (>3%), was resources for the developing seedling by fixing carbon at twice the rate of previously reported to be highly expressed in cucumber fruits, but is not a normal leaf. If the cotyledon is removed during grafting, the rootstock present in the melon or watermelon fruit ESTs in the NCBI database. hypocotyl begins to die. The rootstock hypocotyl continues to senesces Putative homologs of this gene frequently appear in root tissue of other until death which suggests that insufficient reserves were available for species. The majority of transcripts occurring at a frequency of 0.2% the hypocotyl before the newly grafted vegetative tissue could supply or greater were also expressed in melon or watermelon fruit, and there needed resources. The objective of this study was to determine whether was more overlap of these ESTs with cucumber flower ESTs than leaf carbohydrate accumulation in hypocotyls of rootstock and scion mate- ESTs. Several genes showing differential expression at 4 dpp vs. 20 rial directly correlate with grafting success. Three different rootstocks dpp, based on a test run 454 analysis of samples from 0, 4, 8, 12, 16, were used: Lagenaria siceraria cv. Emphasis, Citrulus lanatus var. 20, 26, and 32 dpp fruit, were selected for qRT-PCR analysis. Results citroides cv. Ojakkyo, and Cucurbita mochata x Cucurbita maxima cv. of 454 and qRT-PCR for selected genes were comparable, indicating Strongtosa. Scion material was the same for all rootstocks (Citrulus POSTERS–Sunday that the 454 transcriptome sequencing can be used for analyzing rela- lanatus var. lanatus cv. Tri X 313). Rootstock and scion material were tive gene expression during fruit development. allowed to develop to the appearance of the 1st, 2nd and 3rd leaf consecu- tively at which time grafting was done at each developmental stage. Specified Source(s) of Funding: USDA-SCRI, MSU Rackham Founda- That same time, plant samples were taken of the rootstock hypocotyls tion, and Pickle Seed Research Fund. and scion material for carbohydrate analysis in a destructive manner. (64) Snap Bean Yield and Photosynthesis During After seven days plants were evaluated for grafting success and plants were again analyzed for total carbohydrates in the same procedure as Twilight Extended Field Conditions before. Carbohydrate extraction and analysis were performed using a Meriam Karlsson* methanol:chloroform:water and phenol-sulfuric acid assay. Grafting University of Alaska, Fairbanks, AK; [email protected] success increased with additional rootstock and scion development. Jeffrey Werner Total carbohydrates were positively correlated with plant survivability. University of Alaska, Fairbanks, AK; [email protected] Carbohydrates in the scion material and rootstock hypocotyl increased significantly with each developmental stage. Therefore, grafting should Snap bean (Phaseolus vulgaris ‘Provider’) was direct seeded or trans- be performed at the appearance of the 2nd or 3rd developmental stage to planted after 10 days to high tunnel or field environments during the maximize grafting efficiency and carbohydrate load. summer season of 2008. At the Fairbanks research location (latitude 64°49’N), the month of June had normal average temperatures while (66) Ovary Size at Anthesis in Bell Pepper Is precipitation was 17.3 mm above normal. The average high tempera- ture in July was 4 °C below normal and precipitation more than twice Reduced by Growing Fruits the normal amount. End of season frost was experienced on Sept. 21. Nicacio Cruz-Huerta Yield more than doubled for transplanting versus direct seeding. A high University of Florida, Gainesville, FL; [email protected] tunnel environment also resulted in higher yield than the field. Yield of Rebecca Darnell* pods was 3.1 ± 0.03 kg·m-2 in the field and 3.9 ± 0.11 kg·m-2 in the high University of Florida, Gainesville, FL; rld@ufl.edu -2 tunnel for planted beans. The seeded plants produced 1.1 ± 0.05 kg·m Jeffrey Williamson -2 in the field and 1.6 ± 0.03 kg·m in the protection of the high tunnel. A University of Florida, Gainesville, FL; jgrw@ufl.edu LI-6400 portable photosynthesis system (LI-COR, Lincoln, NE) with a clear top leaf chamber was used to measure net photosynthetic rate (Pn) In bell pepper (Capsicum annuum L.), developing fruits decrease size of of single leaves. Measurements were made intermittently in the field subsequent fruits, possibly by reducing flower ovary size. The objective of this work was to determine the effect of developing fruits on ovary environment for 24-h during July 6 and 7, at 400 ppm CO2. Sunset on July 7 was at 0023 HR with sunrise at 0329 HR Alaska daylight saving size of bell pepper flowers at anthesis. Plants were grown in growth time and the sun remained above civil twilight limits throughout the chambers and pruned to two main axes. About 75 days after planting, 24 h. The average temperature for the 24 h cycle measured one meter one fruit per axis was allowed to set. Eight days after petal fall (DAPF), above ground was 18.7 ± 5.75 °C with a high of 28 °C at 1500 HR and either 0 or 1 fruit per axis was allowed to develop, and examination of a low of 10.5 °C at 0500 HR. Photosynthetic photon flux (PPF, 400 to flowers began in both fruiting (FT) and non-fruiting (NFT) treatments. 700 nm) averaged 433 μmol·m-2s-1 for the 24-h cycle. Over the 24 h, Flowers at anthesis were harvested continuously until fruits on the FT Pn generally correlated to available PPF. Recorded peak Pn was 10.6 reached the mature green stage. Flower and ovary size (8-48 DAPF), -2 -1 cell size and number (8, 28, and 48 DAPF), and carbohydrate content μmol CO2·m s at 1355 HR. In comparison for sweet corn (Zea mays -2 -1 of ovaries (33 DAPF) were measured. In general, fresh weight (FW) of ‘Yellow Supersweet’), peak Pn was 28.3 μmol CO2·m s at 1335 HR. Pn dropped to zero or less from approximately 2300 to 0600 HR in both whole flowers and ovaries in the NFT was greater compared to those in beans and corn under ambient PPF levels of 2 to 30 μmol·m-2s-1. the FT. In the FT, ovary FW of flowers that reached anthesis during the first 28 DAPF decreased gradually. However, ovary FW increased in (65) Carbohydrate Accumulation in Cucurbit flowers that reached anthesis after 28 DAPF, reaching a maximum FW Rootstock Hypocotyls Correlates with Grafting at 48 DAPF, when the fruit demand for carbohydrates had presumably decreased. In the NFT, ovary FW of flowers at anthesis increased during Success the first 32 DAPF, then remained steady. The increase of ovary FW of Frederic D. Memmott* flowers at anthesis in the NFT was accompanied by an increase in the Clemson University, Charleston, SC; [email protected] cell size of the pericarp tissues but not in pericarp thickness. Although Richard L. Hassell developing fruits limited ovary size during the initial rapid growth of Clemson University, Charleston, SC; [email protected] the fruits in the FT, the concentration of soluble sugars and starch in the

HORTSCIENCE, VOL. 44(4), JULY 2009 1127 ovaries was similar in both treatments. These findings indicate that rapid treatment, no significant differences (P = 0.05) among treatments or fruit growth reduces the ovary size of subsequently developed flowers the untreated control for number of red pods, number of green pods, by decreasing cell size, but not the number. The effect, however, does fresh weight red pods, fresh weight green pods, fresh weight dropped not appear to be mediated by carbohydrate differences. pods, fresh weight of diseased (unmarketable) pods, or dry weight of red pods. However, there were significant differences among treatments for the number of dropped pods and the dry weight of these dropped pods. When ReTain® was applied at early bloom (~1700 HUAP), the Crop Physiology/Physiology: number of dropped pods were significantly lower (1.5/plant) than when Growth Regulators the product was applied at first bloom (2.25 dropped pods/plant). Also, when applied at early bloom, the dry weight of dropped pods/plant was Sunday, 26 July 2009 1:15–2:00 pm significantly lower than the control or when the product was applied at first bloom. Although ReTain® applications at early bloom had an (67) Effect of Abscisic Acid on Thinning and Return impact on number and weight of dropped pods, there were no corre- Bloom of Bartlett Pears sponding significant differences in yield. Ethylene may play a role in fruit and flower abscission in paprika, however the application timing Duane W. Greene* of ReTain® used in this study did not produce results that indicate a University of Massachusetts, Amherst, MA; [email protected] significant benefit to using this product. Abscisic acid (ABA) was applied at a rate of 500 ppm to ‘Bartlett’ Specified Source(s) of Funding: Department, College, State, and/or pears in 2007 at bloom, petal fall or the 10 mm stage of fruit develop- HATCH; Private (Association, Foundation, Industry) ment. When final fruit set was taken, ABA reduced set at all times of application. However, the application made at petal fall nearly defruited (69) Effect of Exogenous Gibberellic Acid the trees and also resulted in extensive leaf abscission. ABA applied Application on King Dominance and Endogenous at petal fall increase fruit size. In 2008 ABA was applied to ‘Bartlett’ pears at rates between 50 and 500 ppm when fruit size averaged 10 Gibberellic Acid Level of ‘Granny Smith’ Apple mm. There was a quadratic and highly significant reduction in final frit Jozsef Racsko* set. Fruit weight, fruit diameter, flesh firmness and soluble solids were Ohio State University, Wooster, OH; [email protected] increase linearly by ABA treatments. A factorial experiment was also Diane Doud Miller done on Bartlett pears where ABA at 250 ppm was applied alone and Ohio State University, Wooster, OH; [email protected] in combination with 150 ppm benzyladenine (BA) when fruit averaged Generally, gibberellic acid (GA) is not considered a primary hormone 10 mm in diameter. ABA caused significant thinning, BA had no influ- in the control of fruitlet abscission driven by king dominance. However, ence on fruit set and there was no interaction between ABA and BA. the increase in the amount of indol-acetic acid (IAA) exported from fruit BA increased fruit weight, fruit diameter and soluble solids at harvest. after the application of GA, suggests that GA could function in the king ABA caused some leaf drop and the application of BA with ABA was dominance as a modulator for synthesis and polar IAA transport. The not useful in reversing this response. aim of this study was to find out how exogenously applied GA3+GA4 Specified Source(s) of Funding: Valent BioSciences affects fruitlet abscission and king dominance related to the endogenous GA level of the seeds. Treatments were done at different times [5, 15, (68) Evaluation of Aminoethoxyvinylglycine 25, and 35 days after full bloom (dAFB)] and at their combinations.

(AVG) for Flower Retention in Paprika Exogenous GA3+GA4 application significantly reduced the rate of (Capsicum annuum L.) fruitlet abscission especially for lateral fruits by multiple treatments. King fruit abscission did not differ between GA treatments applied to Mark E. Uchanski* the whole cluster or only to the king fruit. However, the rate of abscis- New Mexico State University, Las Cruces, NM; [email protected] sion of lateral fruitlets was significantly reduced by the spraying of Chile is an important vegetable crop in the desert southwest, and is the lateral fruits only. Even though 5 and/or 15 dAFB treatments were grown in a geographic area called the “chile belt” (west Texas, New effective in lateral fruitlet retention this effectiveness lasted until the Mexico, and Arizona). Paprika is the general term for red chile variet- end of June only. These fruits were subject of June drop. Spraying at ies that are grown specifically for dehydration and subsequent pigment four times was the most effective way in preventing of fruit abscission. extraction. These pigments are used as safe colorants in a wide range of Seed numbers of king and lateral fruits were not significantly different consumer products including cosmetics and processed meats. However, from each other, and were not influenced by GAs treatments either. the pigments associated with deep coloration also appear to be associ- Increasing differences between king and lateral fruits in fruit quality ated with premature fruit (pod) ripening and abscission. In addition, parameters (fruit weight and diameter) were observed with multiple high daytime temperatures in the chile belt during the bloom period application times compared to single treatments. Differences, however, (June and July) can cause flower abscission, possibly due to release of were not found for L:D ratio, skin color, soluble solids content and the plant growth regulator (PGR), ethylene. Both flower and premature firmness. GA3 content of seeds was affected by treatments; the great- fruit abscission can cause yield losses under field conditions. Aminoe- est amount was measured 10 days after treatments, then GA content thoxyvinylglycine hydrochloride (AVG- trade name ReTain®, Valent slightly decreased possibly due to the breakdown or transformation BioSciences), blocks the biosynthesis of ethylene in plant tissues. In into another form of the exogenously applied GAs. this study, we evaluated the effectiveness of the ethylene inhibitor Specified Source(s) of Funding: NCR SARE ReTain® for flower retention in the paprika cultivar ‘NuMex Garnet.’ ReTain® was applied at 250 parts per million (ppm) active ingredient (70) Rootstock Effects on King Dominance with a non-ionic surfactant (0.05% v/v) to direct seeded chile for all treatments in this study. Application dates were timed to correspond in ‘Pink Lady’ Apple with first, early, and peak bloom and were calculated based on heat Jozsef Racsko* units accumulated after planting (HUAP with 86/55oF thresholds). After Ohio State University, Wooster, OH; [email protected]

1128 HORTSCIENCE, VOL. 44(4), JULY 2009 Diane Doud Miller in the studied vegetative growth parameters of conocarpus trees among Ohio State University, Wooster, OH; [email protected] the pruning and paclobutrazol treatments. The 50% pruning with or without paclobutrazol were the most effective treatments in shortening Rootstocks have a great impact on the productivity and precocity of plant height, stem diameter and number of vegetative branches, while scion cultivars through influencing their physiological processes. Thus, it the control gave the highest values for these parameters. Leaf area in can be assumed that rootstocks affect intraspur flower/fruit competition the 50% pruning with or without 500 ppm paclobutrazol, and in the i.e. king dominance and fruitlet abscission as well. In this study, ‘Pink 25% pruning plus 1000 ppm paclobutrazol treatments was less than Lady’ apple characterized with strong king dominance was evaluated in the control where no significant differences in leaf area were found on three different growth inducing rootstocks; M.9 (dwarf), MM.106 between the other treatments and the control. The results showed that (moderate) and seedling (strong vegetative vigor). Increasing flower the pruning and paclobutrazol treatments gave lower fresh and dry number per cluster was observed with decreasing vegetative vigor weights of the branches and whole shoots than the control. The 50% of the stocks, differences, however, were not significant. Significant pruning plus 500 ppm or 1000 ppm paclobutrazol treatment gave the differences in flowering time between king flower and side flowers lowest values for root quality and fresh or dry root weights, while the were found on all rootstocks, differences among side flowers were not 500 ppm, 1000 ppm paclobutrazol and the control treatments resulted expressed. Average fruit set was the greatest for MM.106 followed by in high values for these parameters. It is concluded from this experi-

M.9 and seedling. Fruit set of king flowers was the highest for seedling POSTERS–Sunday ment that pruning of conocarpus trees especially at the 50% pruning and the set of side fruits was the lowest for this stock. The greatest with or without paclobutrazol, helps to decrease their shoot and root ratio of the occurrence of single fruit in a cluster, i.e. the intra-spur growth while the trees remain in acceptable shape. side-fruitlet abscission was for seedling, and thus the king dominance was the strongest from this point of view. Fruit number per cluster at Specified Source(s) of Funding: Myself harvest was the greatest for M.9 and MM.106, that is, significantly greater than seedling. Seed number per fruit was the greatest for M.9 (195) Evapotranspiration and Growth-based Models followed by MM.106 and seedling. Significant differences in seed to Estimate Irrigation of Container-grown Korean number between king fruit and lateral fruits were found for MM.106 Spiraea (Spiraea fritschiana ‘Wilma’) Under Four and seedling stocks only; king fruit had lower seed number than side ones. Fruit weight and diameter was affected by king dominance; sig- Irrigation Regimes nificantly greatest values were measured for king fruit, especially with Aaron L. Warsaw* higher fruit number per cluster. L:D ratio was usually greater for side Michigan State University, East Lansing, MI; [email protected] fruits; these fruits were flattened compared to the king one. However, R. Thomas Fernandez skin color, firmness and soluble solids of king fruit and side fruits Michigan State University, East Lansing, MI; [email protected] were not significantly differed from each other. Generally, better fruit Bert Cregg qualities were measured for M.9 and MM.106. Gibberellic acid (GA3, Michigan State University, East Lansing, MI; [email protected] GA and GA content of the seeds was significantly greater for M.9 4 7 Jeffrey Andresen and MM.106 compared to seedling, however the difference between Michigan State University, East Lansing, MI; [email protected] king fruit and side fruits in GAs content was the greatest for seedling. Decreasing GAs content was measured with the opening order of the Irrigation scheduling and water use are important issues facing the individual flowers in a cluster. nursery industry as concerns about water use regulation, fresh water supplies, and runoff quality are forcing growers to develop water Specified Source(s) of Funding: NCR SARE conserving irrigation programs. Scheduling irrigation of container- grown woody ornamentals using reference potential evapotranspiration

(ETP) and canopy characteristics or crop coefficients to estimate actual

evapotranspiration (ETA) can conserve water compared to fixed irriga- Horticultural Crops Culture and Management: tion rates. The difference in substrate volumetric moisture content 1 hr

Nursery Crops and 24 h after irrigation was used to calculate ETA of 10.2 L container- Sunday, 26 July 2009 1:15–2:00 pm grown Spiraea fritschiana Schneid. ‘Wilma’ plants under 4 irrigation treatments. Irrigation treatments were: 1) a control irrigation rate of 19 mm-ha applied per irrigation application; 2) irrigation scheduled to (194) Response of Conocarpus Trees Growth to replace 100% daily water use (DWU) per application (100DWU); 3) Pruning and Paclobutrazol Treatments irrigation alternating every other application with 100% replacement Fahed A. Al-Mana* of DWU and 75% DWU (100-75); and 4) an irrigation application King Saud University, Riyadh 11573; [email protected] replacing 100% DWU followed by two applications replacing 75% DWU (100-75-75). Irrigation applications were separated by at least Salem M. Aljaman 24 hours. Relationships of ET to reference potential evapotranspira- Falcons Ambition Group, Riyadh 11666; [email protected] A tion (ETP) and growth index (GI) were investigated using regression

This study was conducted at the Educational Farm of the College of Food analysis. The dependent variable ETA was log transformed for all and Agricultural Sciences, King Saud University, Riyadh, to investigate treatments. Relationships for the control, 100DWU, 100-75, and 100- 2 the growth response of Conocarpus erectcus L. trees to pruning and 75-75 treatments included the independent variables ETP, GI, and GI 2 2 2 2 paclobutrazol treatments. Uniform conocarpus seedlings were trans- (R = 0.704); ETP and GI (R = 0.479); ETP, GI, and GI (R = 0.438); 2 planted in 40 cm plastic filled with sandy soil, and grown under wooden and ETP (R = 0.424), respectively. Estimated crop coefficients of the house. Pruning treatments (50% or 25% of plant height) with or without control, 100DWU, 100-75, and 100-75-75 treatments fluctuated dur- paclobutrazol at the rate of 500 or 1000 ppm, and paclobutrazol sprays ing the growing season and ranged from 1.7 to 3.5; 1.7 to 4.3; 2.0 to at the same rates were used. The plants were sprayed with paclobutrazol 5.4; and 1.6 to 6.7, respectively. Relationships of ETA to ETP and GI twice: immediately after pruning (when plants were six months), and suggest that with further research and validation working models for 3 months later. The experiment layout was Randomized Completely irrigation scheduling of container-grown Spiraea fritschiana ‘Wilma’ Block Design ( R.C.B.D.). The results showed significant differences can be developed.

HORTSCIENCE, VOL. 44(4), JULY 2009 1129 Specified Source(s) of Funding: MSU Project GREEEN, MDA Hor- Zn. Plants were grown outdoors in full sun from May to Oct., 2008 ticulture Fund, Spring Meadow Nursery, Inc., Renewed Earth, Inc., on woven nursery groundcloth with a spacing of 90 cm on center. The Harrell’s, Inc. substrate was an 8:1 blend of pine bark to sand with standard amend- ments. Plants were irrigated three times per day at 400 mL of water per (196) Development of a Double Crop Production irrigation using spray stakes so that water was not limiting. Treatments System Using Retractable Roof Houses included a factorial combination of Accelerator™ containers (10.9 Dania Rivera* L) and standard black plastic squat containers (10.1 L) treated or not The Ohio State University, Columbus, OH; [email protected] treated with MicroKote™. Container design had no influence on plant growth or final foliar nutrient concentrations. In July, water loss from Hannah Mathers plants growing in Accelerator™ containers was 69% greater than for The Ohio State University, Columbus, OH; [email protected] plants in black plastic containers. Evaporation accounted for 65% for Luke Case the water lost from Accelerator™ containers, compared to 35% for The Ohio State University, Columbus, OH; [email protected] standard plastic containers. There was no difference in transpiration Double cropping containerized tree liners in a retractable roof greenhouse between types of containers in July. In September, total water loss (RRG) increases the incentive for their production in Midwest nurser- was 23% greater for Accelerator™ containers compared to standard ies. The objectives of this study are to evaluate possible acceleration containers. Evaporation accounted for 53% of total water loss for the of tree production using double cropping in a RRG at The Ohio State Accelerator™ containers compared to 22% for the standard containers. University, Columbus, Ohio with subsequent upshifting to a pot-in-pot Transpiration accounted for 78% of water lost from standard contain- (PIP) system. Two tree species were selected to be grown in the RRG, ers in September compared to 47% for the Accelerator™ containers. Red Maple (Acer rubrum October Glory®) and Littleleaf Linden (Tilia Mean and maximum root zone temperatures from May to October were cordata Greenspire®). All the trees were grown from tissue culture and 27.8 °C and 45.0 °C for the Accelerator™ and 29.7 °C and 49.4 °C they had a start height of 20-25 cm. All the plants were put into 11.3 for the standard container, respectively. MicroKote™ had no influence L containers with a soilless mix in the RRG. The roof and sidewalls on plant growth or final nutrient concentrations in the foliage. Weeds were programmed to close at 21 °C during the day and 10 °C during growing from holes in the sides of the Accelerator™ containers were the night from October to December and plants were irrigated using not a problem in this study, though the author has seen problems in aerial irrigation 3 times/day. From December to March half of the plants commercial nurseries. Under conditions of non-limiting water, plants were with bottom heat (BH) using low watt propagation mats set at 5 grew just as well in both types of containers. Further work is warranted °C and the other at ambient temperature (AT). During winter, plants under conditions of limiting water during nursery production. were watered as needed and protected from freezing temperatures us- Specified Source(s) of Funding: Industry ing a propane heater. From March to June the irrigation was applied using cyclic-micro-irrigation two times/day, applying 500 ml/pot. (198) Use of Switchgrass as the Primary Potting From June to September, irrigation was applied one time/day, applying Component In Nursery Containers 250 ml of water/pot. Plants were fertilized two ways starting in April: control release (CR) fertilizer (40g of 19-5-8) applied at potting and James Altland* a combination of 20g of the CR applied at potting and supplemented USDA–ARS, Wooster, OH; [email protected] with liquid fertilizer (LF) (21-7-7 at 400 ppm) delivered with an injec- Jonathan Frantz tion system every two weeks. The same total nitrogen was delivered USDA–ARS, Toledo, OH; [email protected] in the CR and the CR + LF treatments. Plants were arranged in a split Pine bark is the primary potting component for nursery containers in plot design (main plot–temperature, subplot–fertilizer) with 4 replica- Ohio and other Upper Midwest states. Most pine bark comes from tions. Measures consisted of height, caliper, leaf area, and shoot and lumber or paper mills in southern states. Due to the recent energy root dry weights, EC, pH and NO . No significance differences were 3 crisis, availability of pine bark has declined while the cost to import found between AT and BH for all the measurements. No significance pine bark from southern states has risen dramatically. The objective of differences were found between the CR and CR+LF treatments for this research was to determine if locally grown switchgrass (Panicum height, leaf area, dry shoot and root weights, EC, pH and NO . The 3 virgatum) could be harvested and used as an alternative to pine bark caliper was significantly bigger (8.48mm) in the CR+LF in comparison in nursery containers. Switchgrass was processed through a ham- with the CR (7.82mm). After one year, heights and calipers of linden mermill with a 2.5 cm screen prior to use. Switchgrass was blended (107cm and 8.61mm, respectively) and maple (95.39 cm and 7.76mm, with either 0%, 30%, or 50% sphagnum peat moss by volume. Roses respectively) liners were produced at OSU, supporting our hypothesis (Rosa ‘ChewMayTime’) from 5.7 cm wide cells were potted into 15 that RRG liners can be produced in Ohio. cm tall and wide plastic containers with one of the three substrates. (197) Influence of Accelerator™ Containers Switchgrass with 0% peat moss had low water holding capacity (36%) compared to that amended with 30% or 50% (45% and 53%, and MicroKote™ on Growth and Water Loss of respectively). Substrate pH of switchgrass with 0% peat moss was 6 or Container-Grown ‘Recurvifolium’ Ligustrum greater throughout the experiment. Amendment with peat moss at 30% John Ruter* or 50% reduced pH to between 4.0 and 4.5 throughout the experiment. University of Georgia, Tifton, GA; [email protected] Despite differences in substrate physical properties and pH, substrate type caused no differences in root or shoot growth over the course of A study was conducted to determine the influence of container design the experiment (8 weeks). (Accelerator™ and black plastic containers) and MicroKote™ on the growth, nutrient uptake, and water loss from container-grown Ligustrum (199) Differential Effects of Controlled Release japonicum Thunb. ‘Recurvifolium’. Concern has been expressed by Fertilizer Rates of Growth and Leaf Nutrient growers that plants produced in Accelerator™ containers dry out too fast and weeds grow from the openings on the sides of the container. Concentrations of Containerized Shade Tree Species MicroKote™ is a new micronutrient supplement that is painted on Michael V. Mickelbart* the inside wall of the container and contains Ca, Mg, Cu, Fe, Mn, and Purdue University, West Lafayette, IN; [email protected]

1130 HORTSCIENCE, VOL. 44(4), JULY 2009 Julia Prado were potted into 3.8 L containers with one of the 24 substrate combi- Purdue University, West Lafayette; [email protected] nations. The response of the two species was similar and only growth Michael J. Gosney data for Chinese pistache is presented. After 20 weeks, data for height, Purdue University, West Lafayette, IN; [email protected] shoot dry weight, and root dry weight were gathered. Plant height and Cliff Sadof shoot weight were affected by eastern red-cedar amendment only. Plants Purdue University, West Lafayette, IN; [email protected] growing in 10% (37.0 cm) and 80% (33.8 cm) eastern red-cedar were shorter than plants growing in 0% (42.9 cm). All other amendment ratios Given the number of species grown as ornamentals, the appropriate produced plants with equal or greater height. A similar trend followed fertilization rates for different species is still largely unknown. High for shoot weight. Only plants growing in 10% (15.9 g) and 80% (15.4 rates of fertilization may result in increased growth, but may also g) eastern red-cedar had a shoot weight less than plants growing in 0% contribute to leaf characteristics that make trees more attractive to (17.8 g). Root weight was greater for plants in substrates amended with insects. We tested the effects of five rates (0, 12, 24, 36, and 48 g N) 0.81 kg N·m-3 when eastern red-cedar was 0%, 5%, 10%, or 20% of the of controlled release fertilizer (19-5-8, 8-9 mo.) on the growth, appear- substrate. However, when eastern red-cedar was 40% or 80% of the ance, and nutrient concentrations of four common ornamental shade substrate, root weight was greater when amended with 1.6 kg N·m-3. tree species (Acer rubrum ‘Red Sunset’, Acer rubrum ‘Sun Valley’, There were no visible signs of nutrient deficiencies, substrate shrinkage, Gleditsia tricanthos ‘Skyline’, Malus hybrida ‘Prairiefire’, and Pyrus or allelopathy. Further investigations are warranted to explore the use POSTERS–Sunday calleryana ‘Redspire’) in 15-gal containers. Relative height (RHI) of eastern red-cedar as a substrate amendment. and caliper (RCI) increased linearly with nitrogen rate in all species. However, RCI was not different between the 36 and 48 g N·plant-1 in (201) Assessment of Struvite Containing Controlled any species. The red maples displayed the largest increase in RCI (2.3 Release Fertilizer as a Source of Phosphorus for times the control), while M. hybrida and P. calleryana RCI increases Containerized Ornamental Crops were much less (1.3 and 1.7 times the control, respectively). Individual leaf area was not larger with fertilizer rate in spring or fall sampling, Jim Owen* except in M. hybrida in the fall. Succulence and specific leaf weight Oregon State University, Aurora, OR; [email protected] (SLW) did not change with fertilizer rate in the spring, but succulence Heather Stoven increased and SLW decreased linearly with fertilizer rate in all species. North Willamette Res & Ext Ctr, Aurora, OR; heather. Leaf nutrient samples were collected from all trees except ‘Red Sunset’ [email protected] maple. Nitrogen increased with fertilizer rate in all trees analyzed, Judy Kowalski however, there was no leaf N difference among any of the fertilized North Willamette Res & Ext Ctr, Aurora, OR; judy. trees in P. calleryana (compared to control). This pattern of leaf N was [email protected] correlated with the appearance of the trees: appearance of red maple Kim Phillips trees increased with fertilization, whereas there was no visual differ- Oregon State University, OR; [email protected] ence among the 3 highest fertilizer rates in ‘Redspire’ pear. Leaf Mn Currently, phosphorus use is being scrutinized by state and national concentrations differed dramatically among the species. The highest regulatory agencies because of its contribution to the degradation of fertilizer rate resulted in a 5.2 greater concentration of Mn over the water quality and eutrophication. Phosphorus in runoff can be har- control plants in ‘Sun Valley’, while ‘Prarifire’ and ‘Redspire’ were vested from wastewater by local and state water treatment facilities 2.2 and 2.9-fold higher, respectively. This data suggests that fertilizer and precipitated to form a phosphorus containing mineral that slowly rates can be reduced significantly without a negative effect on groth releases plant available phosphorus. This prilled mineral, struvite, is or appearance in some species, but not others. a magnesium (16%) ammonium phosphate (MgNH3PO4·6H2O) and (200) Eastern Red-Cedar (Juniperus virginiana) as a is available as a 6-month controlled release 6N-29P-0K commercial TM Substrate Component for Container Production of fertilizer (Crystal Green , Ostara, Vancouver BC), To test if a struvite containing 6-month controlled release fertilizer can release phosphorus Woody Plants in controlled manner maximizing plant growth, liners of Hydrangea Jason Griffin* macrophylla ‘Endless Summer’, Juniper horizontalis ‘Youngstown’, Kansas State University, Haysville, KS; jgriffi[email protected] and Rhododendron x Girard ‘Girard’s Fuchsia’ were potted into 2-gal- lon (4L) container and top-dressed with various fertilizer treatments. In many parts of the United States, eastern red-cedar (J. virginiana) is Plants received a conventional 3N-1P-2K ratio 6-mo CRF (control) considered a weed species that will establish on unmanaged land and and a 6-mo hybrid CRF composed of potassium nitrate, ammonium out-compete native grasses. Throughout the Great Plains and Midwest, nitrate, and struvite. The hybrid CRF was formulated to have varying eastern red-cedar is reducing available land for grazing, altering the rate of phosphorus: 0, 0.32, 0.64, 0.94 g P. Each plant was top-dressed soil hydrology, and affecting vertebrate populations. A thriving industry at a rate of 4.6 g nitrogen (N) and 2.4 g potassium (K). Each taxon was has arisen to rid infested pastures of eastern red-cedar. The three step arranged into a completely randomized design with 10 replications per process entails; 1) cutting all plants off at the soil line, 2) allowing cut treatment. Final dry weight data showed comparable results across taxa. plants to dry for one year, and 3) grinding the aged plants. The resulting The contol treatment produced the greatest total dry weights; followed stockpiles of eastern red-cedar chips may be a potential amendment by the taxa receiving 0.32, 0.64, and 0.94 g P. Total dry-weight decreased in container substrates. This is particularly important in regions of the 40% to 70% for plants receiving no phosphorus. The increased crop country where pine (Pinus) trees are scarce. This work describes the growth may be the result of an increased rate of nitrogen release when use of eastern red-cedar as a container substrate component. Eastern using the conventional, homogeneous, fertilizer. Phosphorus did not red-cedar chips were ground to pass a 2.0 cm screen. The chips were appear to limit plant growth when applied at varying rates in the form incorporated at 0%, 5%, 10%, 20%, 40%, or 80% into a 8 pine bark : of struvite. Only in the absence of phosphorus did total dry weight 1 sand (by vol) substrate by reducing the bark component. A controlled significantly decrease. Bronze or red marginal coloration was observed release fertilizer was incorporated at 0.81 kg N·m-3 or 1.6 kg N·m-3 and on all struvite fertilized plants. This discoloration may be a symptom of urea (46-0-0) was incorporated at 0 or 0.4 kg N·m-3. Seedling Chinese inadequate rates of phosphorus uptake. There was no significant effect pistache (Pistacia chinensis) and Indian-cherry (Frangula caroliniana) of treatment on root:shoot ratio; however it was observed that the ratio

HORTSCIENCE, VOL. 44(4), JULY 2009 1131 decreased with increasing applied phosphorus. Struvite is a potential for early-post applications. Early-post applications of mesotrione + source of phosphorus for containerized crop production; however more atrazine to the moderately sensitive genotype resulted in significantly research needs to be conducted to determine needed application rate, higher kernel lutein and zeaxanthin concentrations. No such results release rate, and longevity to ensure plant growth is not limited and is were found for the tolerant genotypes. Data revealed a strong genotypic without foliar discoloration. effect on responses of kernel carotenoids to mesotrione alone, or when tank mixed with atrazine. Specified Source(s) of Funding: Agricultural Research Foundation, Ostara (239) New Uses for Oversized Spinach Leaves as a Fresh Product Hallie G. Dodson* Horticultural Crops Culture and Management: University of Wisconsin, Madison, WI; [email protected] Vegetable Crops M.E. Fitch-Hilgenberg University of Arkansas, Fayetteville, AR; mfi[email protected] Sunday, 26 July 2009 1:15–2:00 pm Teddy Morelock University of Arkansas, Fayetteville, AR; [email protected] (238) Mesotrione Applications Impact Kernel Consumers have become accustom to spinach leaves becoming smaller Carotenoid Concentrations Among Different Sweet in almost all spinach products that are eaten as the fresh product. Some Corn Genotypic Sensitivities spinach genotypes can produce very large individual leaves when Dean A. Kopsell* allowed to grow to a more mature stage and some individual leaves can reach lengths of 18 inches or more. These large leaves offer many The University of Tennessee, Knoxville, TN; [email protected] options for use with various specialty food products whether as wraps Greg R. Armel with the large flat leaves or as individual bowls from the large savoy and The University of Tennessee, Knoxville, TN; [email protected] semi savoy leaves. This could also create a demand for new specialty Thomas C. Mueller products that could be provided by smaller growers. These would be The University of Tennessee, Knoxville, TN; [email protected] very high value products because of the need to hand harvest and to J. Scott McElroy handle the spinach leaves individually. Auburn University, Auburn, AL; [email protected] (240) Microclimatic Factors Associated with Mesotrione (Callisto®) is currently labeled for selective pre- and post-emergence weed control in sweet corn (Zea mays var. rugosa). Enhanced Plant Growth Under Rowcover Mesotrione competitively inhibits the enzyme 4-hydroxyphenylpyru- Ramon A. Arancibia* vate dioxygenase (HPPD), an essential component for the conversion Mississippi State Univ.-MAFES, Pontotoc, MS; [email protected] of tyrosine to plastoquinone. Plastoquinone is a cofactor for phytoene Studies in plasticulture have associated growth with increased tem- desaturase, a critical enzyme for carotenoid biosynthesis. Sweet corn peratures, but plant-water relationships have been overlooked. Studies is one of only a few vegetable sources high in zeaxanthin carotenoids. with spun-bonded rowcover were conducted in Mississippi and the U.S. Carotenoids serve antioxidant functions in photosynthetic processes, Virgin Islands to associate microclimatic parameters with plant growth. as well as in actions of disease reduction in mammalian systems. In Mississippi, rowcover is used in early spring to raise temperature and Sweet corn is tolerant to mesotrione applications; however, differing promote growth in sweetpotato. In our study at the Pontotoc Research sensitivity exist within genotypes. What remains unclear is the impact Station, rowcover and black plastic mulch increased the mean air of mesotrione on carotenoid concentrations in developing sweet corn temperature by 6.5 °C, but the maximum air temperature was 45.5 °C, kernels. Our research objectives were to: 1) characterize crop visual 20 °C higher than without rowcover. In sunny days the temperature injury; and 2) measure kernel carotenoid concentrations in response reached 50 °C and over for most of the day suggesting extreme stress. In to post-emergence applications of mesotrione to cultivars of different contrast, relative humidity was the same, daily solar radiation decreased sensitivities [‘Merit’ (sensitive), ‘Temptation’ (tolerant), ‘Incredible’ in 25% and wind was undetectable under the rowcover. These micro- (moderately sensitive)]. Cultivars were seeded in Knoxville, TN on 1 climatic changes reduced the evapotranspiration under the rowcover May 2008, in a randomized complete-block design with four replications to 44% and doubled plant growth. While rowcover is used only as an at two separate sites. Post-emergence treatments included: 1) untreated insect barrier in the U.S. Virgin Islands since daily temperature ranges control; 2) mesotrione(105 g ai/ha) as early post; 3) mesotrione(105 g between 23 °C and 33 °C, the response in plant growth was similar. ai/ha) as late post; 4) mesotrione(105 g ai/ha) + atrazine (560 g ai/ha) Rowcover increased mean temperature by 1.5 °C only and the maximum as early post; 5) mesotrione (105 g ai/ha) + atrazine (560 g ai/ha) as temperature averaged 38.4 °C, 5.1 °C higher than that without rowcover. late post; 6) atrazine (560 g ai/ha) as early post; and 7) atrazine (560 g Similar to Mississippi, solar radiation decreased in 28% and wind was ai/ha) as late post. Corn plants were 5–10 and 15–20 cm in height for also undetectable under the rowcover reducing evapotranspiration to early-post and late-post applications, respectively. At harvest, eight 58% of the uncovered control. In addition, plant growth doubled under uniform ears were collected from the center of the sprayed area, and rowcover. Therefore, rowcover reduces water stress also resulting in stored 24–48 h at 4 °C. Kernels were cut from a 5-cm section of each ear more favorable conditions for plant growth. for carotenoid analysis. Kernels were freeze-dried and ground in liquid nitrogen prior to carotenoid extraction. HPLC separation was used for (241) An Evaluation of Humates on Disease kernel carotenoid quantification. Data revealed that no post-emergence Resistance of Field Tomatoes to Early Blight treatment with mesotrione alone negatively impacted the concentration of kernel carotenoids, as compared to the untreated control. Visual injury Ronald R. Muse among genotypic sensitivities followed previous research findings; Delaware Valley College, Doylestown, PA; [email protected] however, greater visual injury following post-emergence applications Barbara D. Muse* correlated with higher kernel carotenoid concentrations, especially Delaware Valley College, Doylestown, PA; [email protected]

1132 HORTSCIENCE, VOL. 44(4), JULY 2009 Previous studies have shown that humates enhance the plant’s natural (243) Yield and Sensory Attributes of Four Sweet defense against disease and toxins. A field study evaluated the effect of Corn Varieties in South Central Alabama humate (LC-12 Organic Approach) on ‘Mt. Fresh’ tomato (Lycopersicon esculentum) resistance to early blight. A preliminary greenhouse screen- Desmond Mortley* ing indicated that ‘Mt. Fresh’ was responsive to humate treatments. Tuskegee University, Tuskegee, AL; [email protected] Three levels of humates were used (94, 471, 940 ppm) with controls Conrad Bonsi receiving water. The trial was arranged in a randomized block design Tuskegee University, Tuskegee, AL; [email protected] with four replications of each treatment. Eighty days after planting, Eunice Bonsi leaf tissue was randomly selected from each of the replications for Tuskegee University, Tuskegee, AL; [email protected] nutrient analyses and chlorophyll content. Designated sectons of the Kennedy Aganah field were inoculated with mycelial and spore suspensions of Alter- Tuskegee University, Tuskegee, AL; [email protected] naria solani. Starting eight days later, tomato fruits were harvested Salifu Wahab and data on total yields, percentage of diseased fruit, fruit weight, Tuskegee University, Tuskegee, AL; [email protected] and fruit circumference were compared and analyzed statistically. It was found that nutritional analyses showed no consistent differences Four sweet corn varieties were grown in a randomized complete-block between humate treatment groups and controls. There was no correla- design with four replications during the summers of 2007 and 2008, to POSTERS–Sunday tion between mean leaf chlorophyll and nitrogen in any treatments. The assess adaptation to growth in South Central Alabama. Seeds of Obses- trial also revealed that the control treatment (no humate) performed sion (bi-color SH2), Passion (yellow SH2), Devotion (white SH2), A&C as well or better than humate-treated plants as far as total harvest, 844BC (bi-color SH2) in 2007 only, and Sweet Talk (yellow SH2) in total weight, mean circumference, marketable fruit, and percentage of 2008 only were sown in April of both years in 6-row plots 6 m x 1.8 diseased fruit. Therefore, the tomato field trials revealed overall that m. Fertilizer was applied based on soil test and plants were irrigated the control treatment (no humate) performed as well or better than the using either a drip or overhead system. Plants were harvested at about treatments with humate. 79 days after planting both years and yield and sensory evaluations (2008 only) were done. The number of marketable first and second Specified Source(s) of Funding: PDA Grant ME#443248 ears in 2007 was in the order, Obsession>Passion>Devotion> A#C (242) The Effect of Growing Conditions on 844BC and Sweet Talk> Obsession>Devotion> Passion. The number of days to half silk was shorter and similar for Passion and Obsession Health-promoting Phytochemicals in and longer and similar for Devotion and A&C 844BC in 2007 and only Two Lettuce Cultivars marginally different among varieties in 2008. Sensory analyses showed Myung-Min Oh that the respondents chose Devotion as being very sweet followed by Kansas State University, Manhattan, KS; [email protected] Obsession, Passion and Sweet Talk. Devotion, Passion and Obsession were similar in flavor compared to A&C 844DC. Over all preference Edward E. Carey was in the following order Passion>Sweet Talk>Devotion>Obsession, Kansas State University, Manhattan, KS; [email protected] and approximately 90 % of the respondents expressed their willingness C.B. Rajashekar* to purchase the preferred varieties. Kansas State University, Manhattan, KS; [email protected] Specified Source(s) of Funding: Monsanto and USDA/CSREES Genotype along with growing and management conditions can affect the content and the composition of phytochemicals in plants. A field (244) Evaluation of Three Growth Regulators study was conducted to examine the effect of contrasting growing in Garlic Variety Taiwan (Allium sativum L.) in conditions such as open field and high tunnel on the phytochemical content of two lettuce (Lactuca sativa L.) varieties; a green loose-leaf Sonora, Mexico type, Baronet, and a red loose-leaf type, Red Sails. Three-week old Santiago Ayala* seedlings grown in the greenhouse were transplanted to the open field Universidad de Sonora, Hermosillo; [email protected] or high tunnels. The total phenolic content and antioxidant capacity Jose Juvera-Gonzalez of lettuce leaves increased in response to transplanting to both open Universidad de Sonora, Sonora 83250; [email protected] field and high tunnels. However, the increase was much greater when Gabriela Juvera-Gonzalez seedlings were transplanted to the open field and was more than four- Universidad de Sonora, Sonora 83250; [email protected] fold over the pre-transplant stage. The two major phenolic compounds Fernando Juvera-Gonzalez in lettuce were chicoric acid and chlorogenic acid and their concentra- tions were higher in both varieties when grown in open field than in Universidad de Sonora, Sonora 83250; [email protected] high tunnels. In addition, Red Sails accumulated caffeic acid four-times Jose Juvera-Bracamontes as much in open field as it did in high tunnels. Overall, Red Sails ac- Universidad de Sonora, Sonora 83250; [email protected] cumulated higher amount of phenolic compounds, especially in open Everardo Zamora field, than did Baronet. However, there were no clear differences in Universidad de Sonora, Sonora CP 83000; [email protected] quercetin-3-O-glucoside and ascorbic acid levels either between the Jose Guerrero-Ruiz varieties or the growing conditions. Although lettuce plants grown in Universidad de Sonora, Sonora 83250; [email protected] open field were richer in phytochemicals, they did not do as well in biomass accumulation as those grown in high tunnels. A significant Garlic is one of the most important vegetable growing in Mexico. reduction in shoot and root biomass accumulation occurred when plants Increasing yield and quality is the main goal of the producer. During (both varieties) were grown in open field as compared to high tunnels. this study three growth regulators were evaluated. The used variety was These results show that growing conditions, in addition to genotype, Taiwan, with a population of 300,000 plants per hectare. A randomized can significantly affect the content of many phenolic compounds in complete-block design was used and the treatments were six applications lettuce and that growing lettuce under open field conditions can have per hectare applied in 20 days intervals. Treatments were: 1) Sagastym 500 cm3·ha-1; 2) Cytoburz 500 cm3·ha-1; 3) Biozyme 500 cm3·ha-1; and a positive impact on its health-promoting qualities

HORTSCIENCE, VOL. 44(4), JULY 2009 1133 4) Control. The use of Sagastym was the best with 13.43 tons/ha yield Everardo Zamora and a bulb diameter of 50.09 mm, Cytoburz was in second place with Universidad de Sonora, Sonora CP 83000; [email protected] 13.05 tons/ha and 48.22-mm bulb diameter, Biozyme yield 12.88 Jose Guerrero-Ruiz tons/ha and 47.80 mm bulb diameter. Control got the lowest yield with Universidad de Sonora, Sonora 83250; [email protected] 10.94 tons/ha. These results indicated that the use of growth regulators Giant garlic var. Ampelo is considered as an alternative crop in Sonora, increase garlic yields and improve quality in Sonora, Mexico. Mexico. With the main objective to get better quality and promote ma- Specified Source(s) of Funding: Department, College, State and /or turity this study was performed in Costa de Hermosillo. Clove planting HATCH was in October 2007, with population a density of 50,000 plants per hectare. A randomized complete-block design was used with three stem (245) Evaluation of 3 Lines of the Garlic Variety cuts: 20 cm, 40 cm just at the moment of the stem presence, and a control. Taiwan (Allium sativum L.) Using 3 Fertilizer Rates The best treatment was with cutting at the 40 cm. Yielding an average in Sonora., Mexico of 20.21 tons/ha. and a bulb diameter of 79.6 mm. The second best treatment was at the moment of stem presence with 18.86 tons/ha. and Santiago Ayala* a bulb diameter of 78.7 mm. Cutting at 20 cm. yield 18.54 tons/ha. and Universidad de Sonora, Hermosillo; [email protected] bulb diameter of 77.6. There no was significative differences among Jose Juvera-Gonzalez tratments. Control got lowest yield with 17.29 tons/ha. and a bulb Universidad de Sonora, Hermosillo; [email protected] diameter of 73.7 mm showing a significative differences with other Gabriela Juvera-Gonzalez treatments. results indicate the stem cutting at 20, 40 cm, and at stem Universidad de Sonora, Sonora 83250; [email protected] presence can improve quality and yield in Ampelo giant garlic growing Fernando Juvera-Gonzalez in Sonora, Mexico. Universidad de Sonora, Sonora 83250; [email protected] Specified Source(s) of Funding: Department, College, State and/or Jose Juvera-Bracamontes HATCH Universidad de Sonora, Sonora 83250; [email protected] Everardo Zamora (247) Effects of Chemical Fungicides, Trichoderma Universidad de Sonora, Sonora CP 83000; [email protected] viride and Garlic Extract on Control of Fusarium Jose Guerrero-Ruiz Wilt and Fruit Yield of Round Melon Universidad de Sonora, Sonora 83250; [email protected] Manphool Fageria* In Sonora, Mexico, garlic is one of the most important vegetable University of New Brunswick, Fredericton, NB; [email protected] crop, and evaluation of new varieties in combination with fertilizer is B.D. Yadav considered an important information for growers. During 2007, three Rajasthan Agricultural University, ARS, Durgapura, Jaipur; lines of the garlic variety Taiwan: Line “E”, Line “G” y Line “S” with [email protected] three fertilizer rates: Rate O: Control, Rate 1: 50-0-50+50 Ca, Rate 2: R.B.S. Gurjar 100-0-100+100 Ca y Rate 3: 200-0-200+200 Ca. The best line was Rajasthan Agricultural University, ARS, Durgapura, Jaipur; “G” with rate 1 and 2, average production of 29.98–29.83 tons/ha, [email protected] respectively. This line using rate 1, got the best bulb diameter with P.S. Shekhawat 6.3 cm. The highest yield in line “E” was using the rate 3, with 27.44 Rajasthan Agricultural University, ARS, Durgapura, Jaipur; tons/ha. Bulb diameter with rates 1, 2, and 3 with 6.24, 6.23 and 6.10 [email protected] cm. Line “S” yield the lowest production and there was not significa- Yogesh Sharma tive differences, with 26.14, 25.81 and 25.75 tons/ha in combination Rajasthan Agricultural University, ARS, Durgapura, Jaipur; with rates 3, 2 and 1 respectively. Bulb diameters in this line were [email protected] 6.37, 6.35 and 6.33 using rates 2, 3, and 1, respectively. Control got the Saroj Rolania lowest bulb diameter with 5.59 cm. Garlic yields in this study shown Rajasthan Agricultural University, ARS, Durgapura, Jaipur; that with a population of 400,000 thousands plants per hectare and [email protected] with a proper fertilization, it is possible to get good yield and quality of garlic in Sonora, Mexico. Fusarium wilt, caused by Fusarium oxysporum f. sp. niveum, is a devas- tating disease of round melon (Praecitrullus fistulosus) that may cause Specified Source(s) of Funding: Department, College, State and/or significant yield losses if not managed by seed treatment and well-timed HATCH fungicide applications. To determine the effect of different treatments (246) Effect of Stem Cutting on the Garlic Ampelo on round melon wilt severity and round melon fruit yield, field trials were completed at grower’s field in the Jaipur district of Rajasthan (Allium ampeloprasum L.) Growing in Sonora, provenance of India from 2004 to 2007. Experiments were conducted Mexico in randomized block design with four replications. Treatments included Santiago Ayala* (i) seed treatment with carbendazim at 2 g/kg seed followed by soil Universidad de Sonora, Hermosillo; [email protected] drenching with carbendazim at 0.1% at 35 days after sowing; (ii) seed Jose Juvera -Gonzalez treatment with Trichoderma viride at 8g/kg seed followed by 2.5 kg Universidad de Sonora, Hermosillo; [email protected] powder of Trichoderma viride mixed with 100 kg of vermi-compost/ha as spot application; (iii) seed treatments with garlic (Allium sativum) Gabriela Juvera-Gonzalez extract (100%); (iv) combination of i & iii; (v) seed treatment with car- Universidad de Sonora, Sonora 83250; [email protected] bendazim at 2 g/kg seed followed by soil drenching with carbendazim Fernando Juvera-Gonzalez at 0.1% plus blitox 50 (copper oxychloride) at 0.3% at 35 days after Universidad de Sonora, Sonora 83250; [email protected] seed sowing; and (vi) untreated control. In the treatment iv, the carben- Jose Juvera-Bracamontes dazim dose for the seed treatment was half i.e. 1g/kg of seed). Three Universidad de Sonora, Sonora 83250; [email protected] years pooled data revealed that the seed treatment with carbendazim

1134 HORTSCIENCE, VOL. 44(4), JULY 2009 at 2 g/kg seed followed by soil drenching with carbendazim at 0.1% in the Treasure Valley of Idaho and Oregon infecting onion seed crops plus blitox 50 at 0.3% at 35 days after seed sowing recorded minimum in 1989 and is now known to occur in many onion producing areas percent disease intensity (PDI, 3.75) and maximum fruit yield (17.50 around the world. Onion plants infected with IYSV can progressively tons/ha). This treatment was most effective. However, all treatments loose leaf area, resulting in reduced yield and reduced bulb size. The significantly outperformed the untreated control. Untreated control virus is transmitted by onion thrips (Thrips tabaci). The incidence of recorded highest PDI (50.63) and lowest fruit yield (10.95 tones/ha). IYSV can be increased by inadequate control of onion thrips. Thrips The results will be discussed in respect to integrated management of control has become more difficult through increased thrips resistance Fusarium wilt and sustainable production of round melon. to insecticides. A certain degree of varietal tolerance to thrips and IYSV has been shown. It is not known if management factors such Specified Source(s) of Funding: Self as irrigation and fertilization that reduce plant stress might reduce (248) Influence of Soil Type and Foliar Potassium IYSV expression. Research at the Malheur Experiment Station in 2007 and 2008 evaluated the combined effects of variety, irrigation Fertilization on Fruit Quality and Phytochemical system, irrigation criterion, and N rate on IYSV expression and onion Contents of Muskmelon yield and grade. Each irrigation treatment had split plots with two N John L. Jifon* fertilizer rates (112 and 224 kg N/ha). Within each N split plot, four POSTERS–Sunday Texas AgriLife Research at Weslaco, Weslaco, TX; [email protected] varieties were tested as split-split plots. This report focuses on the Gene Lester four water stress levels tested with drip irrigation. The water stress USDA–ARS SARC, Weslaco, TX; [email protected] levels were achieved by automatic and independent drip irrigation of each plot to maintain soil water tension at 10, 15, 20, or 30 kPa and Consumer Preference Quality attributes (e.g. sweetness, aroma, texture) examine the interactions of irrigation criteria with variety and N rate. are strongly influenced by potassium (K)-mediated processes such as Fertilization at 112 kg N/ha resulted in a higher onion yield and grade protein synthesis, stomatal opening, photosynthesis, and assimilate in 2007 than 224 kg N/ha. There were no differences in onion yield or transport. However, during fruit growth and maturation, soil K supply grade between N rates in 2008, but failed to influence IYSV expression alone is seldom adequate to satisfy K requirements. The effects of soil either year. Iris yellow spot virus symptoms were low in 2007 and no type (sandy versus clay soil) and supplemental foliar K applications significant differences between treatments were observed. In 2008, aver- on quality and phytochemical content of muskmelon (cv Cruiser) fruit aged over varieties and N rates, drier irrigation criteria (higher SWT) were investigated. Starting at fruit set and continuing to fruit maturity, resulted in significantly more severe IYSV symptoms. Averaged over weekly foliar K applications were established using four K salts (KCl; varieties and N rates, drip irrigation at 30 kPa resulted in significantly KNO3; potassium thiosulfate - KTS; and Potassium Metalosate, KM). lower marketable, colossal, and colossal plus supercolossal bulb yield Even though pre-plant soil K concentrations were very high (espe- than the wetter irrigation criteria in both 2007 and 2008, but the differ- cially on the clay soil), supplemental foliar K treatments resulted in ences were more pronounced in the presence of IYSV in 2008. There generally higher tissue K concentrations. Fruit from plots receiving were no significant interactions between variety, irrigation criteria, supplemental foliar K generally had higher soluble solids, sugars, and and N rate either year. phytochemicals (ascorbic acid and β-carotene) than control fruit. The relative responses to foliar K were generally greater on the sandy soil Specified Source(s) of Funding: Western SARE, Idaho Eastern-Oregon than the clay soil. There were no consistent trends among K sources Onion Committee, Oregon State University except for KNO3 which tended to result in poor fruit quality compared to control fruit especially on the sandy soil. The results demonstrate (250) Evaluation of Brassica Greens Cultivars for that mid- to late-season foliar K applications can improve melon fruit Fresh and Processing Production quality and suggest that the relative benefit of this quality improvement Lynn Brandenberger* strategy depends on soil type. The data also reveal differences among Oklahoma State University, Stillwater, OK; lynn.brandenberger@okstate. potential foliar K salts and call for a reassessment of K management edu strategies aimed at improving fruit quality. James Shrefler Lane, OK; jim.shrefl[email protected] (249) Cultural Practices to Reduce the Expression of Iris Yellow Spot Virus in Onion Brassica greens are an important commercial vegetable crop for produc- ers within Oklahoma. These crops are grown for both processing and Clinton C. Shock* for fresh market. Trials were arranged in a randomized block design Oregon State University, Ontario, OR; [email protected] with four replications, each plot consisting of 4 rows on 12 inch row Erik B.G. Feibert centers 20 feet long. Seeding rates were approximately 435,600 seeds Oregon State University, Ontario, OR; [email protected] per acre. Plots were direct seeded in Fall 2007 and Spring 2008 using Lamont D. Saunders a research cone planter. Weed control included 0.5 lb ai/acre of Treflan Oregon State University, Ontario, OR; [email protected] (trifluralin) applied pre-plant incorporated and one hand weeding for Lynn B. Jensen both trials. No other pest control efforts were necessary. The studies Oregon State University, Ontario, OR; [email protected] received 130 to 150 lbs N/acre, respectively for spring and fall. Nine Hanu R. Pappu cultivars were included in both trials. White rust was observed in the Washington State University, Pullman, WA; [email protected] fall trial, but no disease infections were observed in the spring study. The spring trial was rated for bolting (flowering) at harvest and the S. Krishna Mohan fall trial was rated for disease (white rust). Data recorded at harvest University of Idaho, Parma, ID; [email protected] included overall plot yields. Yields varied significantly as did bolting Ram K. Sampangi and disease severity. In general, the authors felt that the most important University of Idaho, Parma, ID; [email protected] aspect of the trials was the opportunity to observe these cultivars for Iris yellow spot virus (IYSV) is known to cause onion (Allium cepa) bolting resistance in the spring. There were significant differences seed stalk and leaf tissue necrosis. Iris yellow spot virus has recently observed between different cultivars with the Kales being the most been recognized as a serious disease of onion. It was first found locally bolt-resistant. Highest yielding cultivars in spring the trial included

HORTSCIENCE, VOL. 44(4), JULY 2009 1135 Darkibor kale, Miike Giant Mustard, and Savannah mustard spinach. the undergraduate plant agricultural sciences. The participating institu- Highest yielding cultivars in the fall trial included Summer Fest and tions created the Alliance for Cooperative Course Exchange in the Plant Green Boy mustard spinach (Brassica rapa). Sciences (ACCEPtS) which will serve as a mechanism to create and share courses. To initiate this project, an initial group of eight courses Specified Source(s) of Funding: Landgrant university research project are being developed that will be shared by the participating institutions in their plant agricultural science curricula. This approach provides for a significant amount of flexibility for the participating institutions to utilize the shared courses as best serves the needs of their departments Teaching Methods and students. Additionally, the participating institutions have agreed Sunday, 26 July 1:15–2:00 pm to a tuition exchange program under which 20% of the tuition from courses shared through the ACCEPtS program will be retained by the (24) An Exercise to Improve Laboratory Write-ups ACCEPtS program for operations and future course upgrades and development of new courses. This will allow the ACCEPtS program in Plant Propagation to grow and respond to emerging needs in the future. The ACCEPtS Richard Criley* program is also designed to grow by allowing other institutions to join University of Hawaii, Honolulu, HI; [email protected] ACCEPtS. In addition to improving the curricula available to students, this program will improve the efficiency with which the participating A suggestion from an end-of-the-semester course evaluation led to institutions utilize their teaching resources and their ability to offer the an exercise that has improved the quality of student reports in plant type of curricula needed to prepare students for careers in the plant propagation labs. An experiment, usually involving an auxin series, is agricultural sciences. set up some weeks in advance of the semester. Depending upon the plant material chosen, five to seven auxin concentrations, including an (26) Embracing Social Networks as a Tool for appropriate control, are applied as basal dips or soaks. in the second Strengthening Communications with Alumni lab of the semester, students evaluate the results and develop root qual- ity indices using a supplied form. Handouts include a list of the steps Dan Stearns* (not necessarily in order) undertaken in setting up the experiment, and Pennsylvania State University, University Park, PA; [email protected] students are expected to organize their materials and methods section Michael Reinert based upon this information. Instructions are provided for the lab Iowa State University, Ames, IA; [email protected] report format, and anonymous sample write-ups from previous years Michael R. Mohney are supplied as examples. Students are expected to search the litera- Pennsylvania State University, University Park, PA; [email protected] ture for relevant research and include these in their literature review and discussion. Including tables or graphs, most papers are about 3-4 Social networks such as Facebook and MySpace have become the pages long. The instructor evaluates the write-ups using a rubric and preferred communication system for many students and for an increas- returns the papers to the students, who then (are supposed to) use them ing number of faculty. At the urging of recent alumni, a Facebook as a guide to write-ups due during the remainder of the course. The group was established to strengthen communications between faculty exercise has had the desired effect of improving lab write-ups in the in the department of horticulture at Penn State and graduates of the department’s landscape contracting curriculum. The group, titled Penn plant propagation course State Landscape Contracting Alumni, debuted in July 2007 with no (25) The Alliance for Cooperative Course Exchange marketing or general announcement to graduates. After 2 months 21 in the Plant Sciences alumni had discovered the group and joined. After 12 months member- ship had increased to 71. After twenty months membership reached Michael Evans* 138, which represented 20.2 percent of the total number of graduates University of Arkansas, Fayetteville, AR; [email protected] from the program. The site is used for group communications as well Donna Graham as individual contacts. Announcements, events and career opportunities University of Arkansas, Fayetteville, AR; [email protected] are posted by faculty. A side benefit of the Facebook group is increased Janet C. Cole communication among alumni classmates. Oklahoma State University, Stillwater, OK; [email protected] (27) Faculty Indicate Need for Instructional Edwin Miller Oklahoma State University, Stillwater, OK; [email protected] Multi-media Resources for Use in Teaching Richard Harkess Nursery Production Mississippi State University, Mississippi State, MS; rharkess@pss. Amy N. Wright* msstate.edu Auburn University, Auburn, AL; [email protected] Walter Taylor Mengmeng Gu Mississippi State University, Mississippi State, MS; RHarkess@pss. Mississippi State University, Mississippi State, MS; [email protected]. msstate.edu edu Jeff Kuehny James Robbins Louisiana State University, Baton Rouge, LA; [email protected]. University of Arkansas Coop. Extn., Little Rock, AR; [email protected] edu Elizabeth Garrison An online survey was conducted in Fall 2008 regarding the instruc- tion of college level courses in Nursery Production. Instructors at 103 Clinton, LA; [email protected] land-grant universities were contacted, and 54 completed the survey Reductions in teaching resources and the loss of teaching positions (52% response rate). Thirty schools indicated that they currently have made it difficult for departments in the plant agricultural sci- offer a course in Nursery Management/ Production with an average ences to provide courses and maintain high quality curricula. This enrollment of 25 students. Multimedia tools (video, web, etc.) were phenomenon has resulted in a less diverse and thorough curriculum in used at almost all schools, however, availability of multimedia tools

1136 HORTSCIENCE, VOL. 44(4), JULY 2009 for Nursery Production topics and the difficulty of integrating current (29) Introducing Modern Molecular Biology resources into existing courses limited their use in classroom. Almost and Biotechnology to Students and Public in all respondents agreed that a set of instructional DVDs containing video footage of key aspects of nursery management/production Kentucky Areas would be helpful to provide or supplement instruction of some or Li Lu* all topics. Additionally, it was indicated that DVDs would be most Kentucky State University, Frankfort, KY; [email protected] helpful if content was arranged by topic rather than by individual Kirk Pomper nursery. Although half of respondents indicated that instructional Kentucky State University, Frankfort, KY; [email protected] DVDs couldn’t completely substitute for current field trips, most Karan Kaul all agreed that DVDs could effectively substitute for field trips that Kentucky State University, Frankfort, KY; [email protected] they currently are not able to take and for aspects they are not able to Narayanan Rajendran observe in person. One respondent indicated, and the authors agree, Kentucky State University, Frankfort, KY; narayanan.rajendran@kysu. that field trips are better for providing overviews of nursery operations edu and allowing students to actually see what a nursery looks like rather than showing detailed images of all the individual aspects of nursery James Tidwell management/production. Short video footage segments can easily be Kentucky State University, Frankfort, KY; [email protected] POSTERS–Sunday incorporated into classroom lectures and can provide close-up images Modern Molecular Biology and Biotechnology impact multiple areas of and instruction on specific components like fertilizer application, of biology and chemistry, such as genetics, biochemistry, cell biology, pruning, potting machines, etc. that may not be visible or accessible medicine, and agriculture. Training in biotechnology and molecular if simply touring parts of a nursery. Cost, transportation logistics, biology techniques is critical for students who wish to pursue careers time, and availability of nearby qualified nurseries were cited as the in the life sciences and agriculture. Two USDA 1890 Institution Ca- main issues associated with including field trips as part of the course. pacity Building Grants “Development of Biotechnology Courses to Accessibility was the main obstacle to observing somewhat special- Enhance Aquaculture and Life Science Programs and Recruit Students ized topics such as bare-root harvesting/grading/storage, international to Kentucky State University” and “Creation of Summer Educational issues, and innovation/mechanization. Respondents were asked to Opportunities in Biotechnology to Recruit Students and Enhance Stem identify nurseries they would visit if time, money, and resources Areas at Kentucky State University” were funded in 2005 and 2008 were not limiting. Many identified several major nursery operations respectively to implement a biotechnology training pipeline from middle which are some of the most important in terms of technology, scope school through post-secondary education, and provide experimental of operations, and plant material but are often too far away to visit. experiences in modern biology to students and the public in Kentucky. Additionally, most respondents, when asked which states they would For post-secondary students, two undergraduate courses “Understand- like to visit, listed states covering a very broad geographic range, one ing Biotechnology” and “Advanced Molecular Biotechnology” have which could not feasibly be covered by a single class. been offered and about 50 students have participated in the courses. The students gained experience using common tools of molecular (28) USDA–CSREES–ISE Competitive Program biology (e.g., DNA isolation, Southern and Western Blots, DNA se- quencing, and PCR), genetic engineering, cloning, gene therapy, the Award (2006) Funding for Internationalization of human genome project, forensic DNA, bioremediation, biodiversity, Biology Curriculum in Sustainability: Development and bioterrorism in the class, and gained “hands on” experience in the Programs in Progress at M.S. Swaminathan laboratory portions. The students also learned the applications of vari- Foundation, Chennai, India ous molecular and bioinformatics databases and software, including Genbank, EMBL, BLAST, etc. The grants also provided the students Usha Palaniswamy* with research internship opportunities in multiple research laboratories. Albany, NY; [email protected] The students applied the techniques they learned in the classes to a A justification for the development of a major in environmental stud- research environment, and presented their research outcomes in national ies/sciences and sustainability will be presented. A new course BIO /local scientific meetings. The courses and research experiences laid 419 Sustainability through Empowerment and Ecotechnology that is the ground work for graduate school opportunities and biology-related being developed includes international content form the sustainable careers after graduation. More courses and summer-workshops will be development programs in progress at the M.S. Swaminathan founda- offered to students and the public to promote understanding of modern tion (MSSRF), Chennai, India. The strategic themes (sustainability, biology and biotechnology. stewardship and science) as well as the integrative themes (ecosystem Specified Source(s) of Funding: 1890 Institution Capacity Building capital, policy and politics, and globalization) and their elements are Grant identified in selected development programs at the MSSRF. This course describes with specific examples the application of natural (30) Week Long Practicum Course to Teach resource management practices, ecotechnology and empowerment Landscape Contracting Skills strategies including community-based, information communication technology-mediated functional literacy and bio-villages as means Alex X. Niemiera to achieve sustainability. Emphasize is on low input and high value VPI & SU, Blacksburg, VA; [email protected] output and improving efficiency in management systems, the develop- J. Roger Harris* ment of sustainable ecoenterprises as well as blending natural resource VPI & SU, Blacksburg, VA; [email protected] management and livelihood security. Extensive training programs College and university curricula often offer courses via the traditional are frequently held with regular field level interactions and ongoing classroom format. Due to the nature of a landscape contracting cur- evaluations in progress. ricula, courses are most effective when they combine fundamental Specified Source(s) of Funding: USDA-CSREES-ISE Competitive information of a classroom format with practical experience garnered Grants Program in an “on-site” or a lab setting. Landscape contracting topics such as

HORTSCIENCE, VOL. 44(4), JULY 2009 1137 planting techniques, irrigation, and hardscape materials and installation Student experiential learning opportunities and outcomes were major are examples where a “real world” exposure to the subject material is components of the 2008 Mid-American Poinsettia Trials conducted at invaluable. Thus, to better prepare students for careers in landscape Kansas State University, the University of Illinois and Virginia State contracting, we developed a yearly landscape contracting practicum University. At each location during Fall 2008, students in traditionally- course. Beginning in Fall 1997 and every year thereafter, we offer a taught plant science and horticulture courses produced poinsettias that four-to-five day practicum course that is held the week prior to the fall were part of the cultivar trials. Various aspects of poinsettia production semester. The goal of the practicum courses is to expose students to and marketing were covered throughout the semester using lecture the fundamental concepts as well as the hands-on aspects of a range of and lab formats. Student learning outcomes were quantified using an landscape contracting topics. Student feedback has been very positive assessment with self-reported scores (Likert-type scale of 1 to 6 where about the subject matter and skills obtained during the courses. The 1 = strongly disagree and 6 = strongly agree) in response to a series of overall student evaluation of each course has been at least a 3.7 (out written statements. The same assessment instrument was given at the of 4.0) for the 12 courses. A distinct advantage to the week-long class beginning and end of the semester. A total of 37 students across loca- format, in contrast with a weekly three-hour lab, is the continuity of tions completed both the pre- and post-assessments. Scores showed the subject matter and start to finish project format. greatest increases with regard to familiarity with poinsettia cultivars and their traits, and showed moderate increases related to crop quality Specified Source(s) of Funding: College of Agriculture and Life Sci- traits and crop production practices. Scores increased least with regard ences to marketing considerations such as consumer preferences. Results (31) Virtual Field Trips in a Tropical Production suggest that experiential learning opportunities during production of a range of commercial poinsettia cultivars yielded positive learning Systems Course outcomes despite the differences in teaching methods implemented Kent D. Kobayashi* among the three universities. University of Hawaii at Manoa, Honolulu, HI; [email protected] Specified Source(s) of Funding: University teaching funds and private Kauahi Perez industry in-kind donations University of Hawaii at Manoa, Honolulu, HI; [email protected] Field trips play an important role in a horticultural course. Visits to (33) Kids University—Yard and Garden Sleuths; farms and nurseries add much to a course by giving students firsthand A Week Long University of Minnesota Youth experience. However, a problem with field trips is the students visiting Program That Introduces 8-to 9-Year-Old Students the same farms/nurseries in several different courses. In addition, there is the cost and availability of transportation by van and private cars on to Horticulture through Campus Horticultural the island of Oahu or airfares and rental cars on the neighbor islands. Resources The objective of this study was to determine the feasibility of using David Zlesak* virtual field trips to supplement actual field trips in an undergraduate University of Minnesota Extension, Andover, MN; [email protected] tropical production systems course. Students were surveyed to find out Karyn E. Vidmar who has had work experience on a farm/nursery. This included students University of Minnesota Extension, Farmington, MN; vidm0009@umn. whose family had a farm/nursery or who were owners of a farm/nurs- edu ery. Students were to take photographs of the farm/nursery and gather Nancy L. Mulholland information about its operation. The goal was to give a presentation University of Minnesota, Chaska, MN; [email protected] to the rest of the class as if they had actually visited the farm/nursery. Students gave excellent PowerPoint presentations about the farms and Kathryn Zuzek nurseries they had work experience with or had visited. These included University of Minnesota, Victoria, MN; [email protected] several students who went on a field trip to a hydroponic vegetable Kids University is sponsored by the University of Minnesota Recre- farm on Oahu for a vegetable production course. A student visited a ational Sports Department and coordinates a diverse assortment of hydroponic vegetable farm on the island of Maui during spring break summer programs on the St. Paul, University of Minnesota campus for for his presentation. Questions from the class indicated much student youth that vary in duration, topic, and student age. Beginning in 2004 interest in these horticultural enterprises. Of particular value was the and repeated in 2005, 2007, and 2009, members of the Department presentation by a student who owned a mondo grass farm, giving an of Horticultural Sciences partnered with Kids University to develop owner’s perspective. Another insightful presentation was by a student a week long course focused on introducing eight and nine year old who worked on a family farm on the U.S. mainland which emphasized students to horticulture. The course fees are split between the two crop diversity. The virtual field trips presented by the students offered sponsoring groups. The course is named Yard and Garden Sleuths and the class much needed exposure to farms and nurseries that the class offers a hands-on, detective-like learning style to introduce students to did not have a chance to visit. These included places on the U.S. main- horticulture. The course is also designed to introduce students and their land, the neighbor islands of Maui and Hawaii, and farms/nurseries families to the campus and additional university resources. Students not ordinarily visited in other departmental courses. Virtual field trips spend half a day studying horticulture and the other half day engaged offer a viable alternative to actual field trips. in recreational sports coordinated by the Recreational Sports Depart- ment. This course provides a unique and dynamic learning experience (32) Student Learning Opportunities as a for youth and provides campus faculty and students (graduate and Component of Poinsettia Cultivar Trials undergraduate) with the opportunity to work with younger students Christopher J. Catanzaro* than is typical on a college campus. Yard and Garden Sleuth course Virginia State University, Petersburg, VA; [email protected] coordinators bring together interested Department of Horticultural Kimberly A. Williams Sciences members each year, connect them with individual lessons Kansas State University, Manhattan, KS; [email protected] and activities for them to lead in their area of expertise and interest, and mentor them as they prepare age-appropriate instructional mate- Daniel F. Warnock rial. The general curriculum outline builds chronologically throughout University of Illinois, Urbana, IL; [email protected]

1138 HORTSCIENCE, VOL. 44(4), JULY 2009 the week- Monday: introduction to gardens, seeds, soils, and worms; (6) Evaluating a Columnar Population of Pink Lady Tuesday: plant parts and plant identification; Wednesday: plants as a and Fuji Seedlings commodity; Thursday: how plants capture light energy; and Friday: pollinators and their interaction with flowers and harvest. Each day Julia M. Harshman* is comprised of several short activities that support specific learning University of Maryland, College Park, MD; [email protected] objectives, and student interest is maintained through integrating spe- Christopher Walsh cial speakers, discussions, experiments, field trips, crafts, and snacks University of Maryland, College Park, MD; [email protected] that compliment different learning styles. The scientific method is This project was initiated in 1991 with an open pollination of McIntosh emphasized through a couple of targeted experiments throughout the Wijcik by Gala to produce an initial population of compact seedling week as students ask questions, set up the experiments, take data, and trees. The goal was to incorporate the precocity of Gala into a short- discuss results. The greenhouse classroom serves as the home base statured, spur-type tree. Precocious seedlings from the original cross for the class and the nearby display and trial garden, student organic that were tolerant to late-spring freezes were selected at Keedysville, farm, woods, and College of Biological Sciences Greenhouses serve as MD. Field tolerance to fireblight was also evaluated following summer frequent field trip destinations. Students are given plants, cut flowers, hailstorms. First generation trees were then hybridized with commercial and/or seeds to take home each day. On the last day of class, students cultivars such as Pink Lady, Fuji, Braeburn, Commander York, and Red POSTERS–Sunday are given an age-appropriate gardening book to provide them with a Yorking that are adapted to hot, humid climates. Seedlings from the resource for continued learning. crosses were germinated and initially evaluated in the greenhouse and th Specified Source(s) of Funding: Department, College, State, and/or set in the field. In January 2008 (at the end of the 5 leaf) trees were HATCH, University of Minnesota, and the Minnesota Agricultural sorted by phenotype. Approximately 90% of the wild-type trees were Experiment Station then removed, but all of the columnar trees were retained. The Pink Lady and Fuji populations were evaluated for bloom in April, and tree height, tree spread and fireblight in June. After a series of hailstorms in August, the number of fireblight strikes per tree was counted. Harvest Undergraduate Poster Session and and fruit analysis was conducted weekly from September 5th until October 10th. The data recorded for a representative sample of the Competition - Session 2 fruit included weight, height, width, soluble solids, firmness, ground Sunday, 26 July 2009 6:00–7:00 pm color, red color and starch. From the tree size data measurements, the compact populations of Pink Lady and Fuji trees had different tree architecture, but only a slight difference in precocity when compared Note: You must stay with your poster for the full session with their wild-type populations. The wild-types for both Fuji and Pink time period. Lady had a height to spread ratio of about 1.4. Compact Pink Lady trees had an average height to spread ratio of 3.38 while the compact Fuji trees had a ratio of 3.92. Fireblight strikes per tree were similar (4) Chilling Requirement to Overcome Bud for both populations. Fruit for both compact populations were heavier, Dormancy in Chokecherry but the length-to-diameter (L/D) ratios were identical. Soluble solids were comparable, with a slight but measureable difference in fruit firm- Jeremy R. Crook* ness. Fruit from wild-type trees in both cultivars was slightly smaller Utah State University, Logan, UT; [email protected] and firmer. Using the data and taste-test notes made while performing Brent L. Black the fruit analysis, elite selections from these Pink Lady and the Fuji Utah State University, Logan, UT; [email protected] populations were identified. We expect to have clones available for Chokecherry (Prunus virginiana) is a native North American plant that commercial trials by 2010. has the potential of becoming a regionally important alternative fruit Specified Source(s) of Funding: Maryland Agricultural Experiment crop. Fifteen open-pollinated seedling populations collected from the Station, Maryland State Horticultural Society and the Francis R. Intermountain West were subjected to chilling temperatures (4 °C) for Gouin Fund 0, 2, 4, 6, 8 and 10 weeks, and then held under long day conditions (16 h) at 20 ± 2 °C for four weeks. Bud break and shoot growth were (7) Seed Propagation of Sphaeralcea (Globemallow) then measured on replicate plants to determine chilling requirement for Ailina Smith* breaking bud dormancy. There was no significant budbreak at less than Utah State University, Logan, UT; [email protected] 4 weeks of chilling, whereas plants chilled for 10 weeks showed 100% budbreak. The amount of chilling required to produce >80% budbreak Heidi Kratsch differed among seedling populations, and ranged from 6 to 10 weeks. Utah State University, Logan, UT; [email protected] The effect of chilling time on terminal shoot elongation also differed Plants of Sphaeralcea are flowering perennials with bright orange to among seedling populations. Some populations showed maximum red flowers that add color to landscapes. They are drought-tolerant and elongation after 6 weeks of chilling, whereas shoot elongation in other considered pioneer species because of their ability to establish quickly populations continued to increase through 10 weeks of chilling. There in harsh conditions. Three species are native to the Intermountain West did not appear to be any correlation between chilling requirement for and considered desirable for low-water landscapes: S. grossulariifolia, budbreak, and the effects of chilling on terminal shoot growth. These S. parvifolia, and S. munroana. While plants of Sphaeralcea are avail- results indicate genetic variation in chilling response. Among these able in the industry, they are not widely distributed because of difficulty Intermountain West ecotypes, 10 weeks of chilling maximized both with seed propagation and dormancy breaking. A reasonably successful budbreak and terminal shoot growth. strategy for breaking physical seed dormancy in Sphaeralcea is seed nicking. However, this method is not cost-effective on a large scale Specified Source(s) of Funding: Utah Botanical Center, Utah State because the seeds are small (<1 mm in diameter) and seed nicking is University labor-intensive. We hypothesized that seeds of Sphaeralcea might

HORTSCIENCE, VOL. 44(4), JULY 2009 1139 exhibit double dormancy. In February 2009, seeds in lots of 50 each are best suited to Colorado’s unique environment. Three treatments of were exposed to physical (seed nicking, rock tumbling for 24 hr, and floating row covers over salad were evaluated in terms of temperature hot-water scarification) and physiological (6 weeks cold-moist stratifi- ranges experienced, plant development, and nitrate accumulation. Ten cation) dormancy breaking strategies, alone and in combination to test suitable crops were planted in a certified organic, unheated high tunnel at this hypothesis (n = 5). After dormancy treatments were complete, seeds Colorado State University’s Horticulture Field Research Center. Lactuca were germinated on moist filter paper in plastic Petri dishes held on a sativa (‘Winter Density,’ ‘Galisse,’ ‘Cherokee,’ ‘Focea,’ ‘Magenta’), bench top at 21 °C. Germination was recorded as radicle emergence Valerianella locusta ‘Vit,’ Diplotaxis tenuifolia ‘Sylvette,’ Brassica from the seed. We found no interaction between species and treatment rapa ‘Mei Qing,’ Brassica rapa ‘Early Mizuna,’ and Brassica juncea in percent germination among the three species (P = 0.87). Germina- ‘Yukina,’ were direct seeded on Oct. 30, 2008. The treatments consisted tion of seed after nicking alone was 52%. Germination of seed after of 1) “1X” a single layer of floating row cover (FRC) (Agribon19 6 weeks cold-moist stratification was only 5%. However, the combi- 0.5oz. spun bond polyester) suspended with wire hoops, 2) “2X” two nation of nicking and 6 weeks cold-moist stratification significantly layers of FRC suspended with wire hoops, and 3) “0X” uncovered. The enhanced seed germination over either of these dormancy breaking treatments were replicated three times over nine completely random- strategies alone (84%). Seed germination percent after rock tumbling ized beds. Three lettuce varieties, ‘Galisse,’ ‘Cherokee,’ and ‘Focea,’ alone was 26%, significantly greater than hot-water scarification. Cold- were analyzed for nitrate accumulation at harvest on Feb. 11th, 2009. moist stratification did not improve germination when combined with Temperature increases over external temperatures of 2.90 °C, 6.82 °C, physical dormancy breaking strategies other than nicking. Our data and 7.61 °C were observed for 0X, 1X, and 2X treatments, respectively, suggest that Sphaeralcea may exhibit double dormancy. Future work while minimum temperatures were elevated 9.94 °C, 19.59 °C, and should focus on evaluating different rock-tumbler media and time of 21.79 °C, respectively. Lettuce varieties showed a 436% increase in tumbling to find a viable alternative to nicking for breaking physical mean plant mass between the 0X and 1X treatments, but only a 23% seed dormancy in these species. increase between the 1X and 2X treatments. Asian greens showed disparity, with ‘Mei Qing’ and ‘Yukina’ showing an increased mass Specified Source(s) of Funding: Utah State University Undergraduate between 1X and 2X treatments of 90.9% and 89.8%, but with ‘Sylvette’ Research and Creative Opportunities program and ‘Early Mizuna’ showing decreased mass of 207.0% and 64.8%. (8) Relation Between Metal Accumulation Nitrate accumulation increased with the amount of covering, but dif- fered by variety, with mean concentrations for ‘Cherokee,’ ‘Focea,’ and Surface Characteristics of Leaves and Stems in and ‘Galisse’ of 190.4, 150.4, and 157.0 mg/kg NO for 0X, 415.0, Two Cultivars of Sweetpotato [ (L.) 3 Ipomoea batatas 683.4, and 439.3 mg/kg NO3 for 1X, and 727.3, 1176.3, and 577.1

Lam.] ‘Commensal’ and ‘Salyboro’ Under mg/kg NO3 for 2X treatment, respectively. No sample demonstrated Salt Stress nitrate levels above the European Commission regulated safety level of 4500 mg/kg NO3. Results indicate that organic winter production Andre James* of salad greens in unheated high tunnels with the use of floating row Chicago State University, Chicago, IL; [email protected] cover is a viable option for Colorado growers, but differential responses Stefanie G. Owens to the thickness of cover necessitates further study to determine best Chicago State University, Chicago, IL; [email protected] management practices for individual crops. Devi Prasad Potluri Specified Source(s) of Funding: CSU Specialty Crops Program, Chicago State University, Chicago, IL; [email protected] Dept. Axillary bud cultures of two cultivars of sweetpotato Ipomoea batatas (L.) Lam. ‘Commensal’ and ‘Salyboro’ were subjected to salt stress under in vitro conditions for 8weeks. Relative salt concentrations ranged from 0 to 150 mM. Samples were collected after 2, 4, and 6 days after Crop Physiology/Physiology: exposure to salt. Another sampling was done at the end of the growing Postharvest 1 period. The present work reports the results on the early effects up to 6 days. Observations were made on stems and leaves using scanning Monday, 27 July 2009 12:00–12:45 pm electron microscopy. Metal analysis was carried out by ICP-Ms. SEM Analysis revealed that in both cultivars stomata distribution and the (92) Analytical Evaluation of Capsicum Germplasm guard cells shape was affected by salt above 50 mM. Trichome distri- bution and shape was also affectd. Accumulation of metals, especially Resources for Genetic Improvement of Aroma and micronutrients like Fe, Mn, Cu, and Zn as well as levels of K have some Flavor in Pepper Fruit correlation with the morphological changes. These and other results Elena Albrecht are further discussed in relation to salt tolerance mechanisms of these KeyGene N. V., Wageningen; [email protected] two cultivars of sweetpotato. John Stommel Specified Source(s) of Funding: LSAMP program, CSU USDA–ARS, Beltsville, MD; [email protected] Eunhee Park (9) Evaluation of Organic Winter Greens Production USDA–ARS, Food Quality Lab, Beltsville, MD; [email protected]. in Unheated High Tunnels gov Matthew Espe* Robert Saftner* Fort Collins, Colorado; [email protected] USDA–ARS, Food Quality Lab, Beltsville, MD; [email protected]. gov The winter production of cold tolerant organic crops using unheated high tunnels in Colorado shows promise due to high light intensity Capsicum germplasm includes five domesticated species and 25 wild and abundant cloud-free days; however, to date, no studies have been species. C. annuum is widely grown worldwide and includes the eco- performed to identify appropriate crops and management techniques nomically important sweet bell pepper. Related germplasm resources offer rich diversity for genetic improvement of C. annuum. Introgression

1140 HORTSCIENCE, VOL. 44(4), JULY 2009 of novel fruit flavor attributes from domesticated and wild species affords 4 after treatment. The increase of all antioxidants indicates the response new opportunities to improve pepper fruit flavor. We have identified of the tissue to the reactive oxygen species by scavenging free radicals. Capsicum accessions with unique aroma and flavor attributes. A gas The activities of POD, ascorbate peroxidase, monodehydroascorbate chromatography (GC)-mass spectroscopy-olfactory detection system reductase were lower in chilled fruit than in the control. In conclusion, was utilized to characterize fruit aroma volatiles, and GC-flame ioniza- chilling inhibited the activities of multiple ascorbate-glutathione cycle tion detection was used for quantification of TMS sugars and organic enzymes, while heating increased the activities. This may explain why acids. Over 150 volatiles have been identified in selected accessions, chilling causes permanent injury to tomatoes but heating improves the half of which have not been characterized previously in fruit of C. resistance of tomatoes to stress. annuum. Some accessions with unique flavor attributes were distinct from other accessions, particularly C. annuum cultivars, in having (95) Changes in Visual Fruit Quality and relatively high concentrations of various esters with fruity, floral or Antioxidant Content at Harvest and uncharacterized aromas, sesqueterpenes with woody, spicy, herbal and Following Cold Storage of Pepper Fruits uncharacterized aromas and relatively polar volatiles some of which had malodorous odors. Many individual volatiles, mostly aldehydes, Harvested from Plants Fed with Nutrient ketones and alcohols, having ethereal or green-grassy aromas and two Solutions Containing Hydrogen Peroxide pyrazines having ginseng or bell pepper aromas were present in all ac- Tissa Kannangara* cessions evaluated. Concentrations of most volatiles decreased during Agriculture and Agri-Food Canada, Agassiz, BC; [email protected] fruit ripening whereas 1-penten-3-ol, 3-pentanone, 1-hexanol and (E)-2- Wei Lin hexen-1-ol increased. Preliminary evaluations indicate variations in the Agriculture and Agri-Food Canada, Agassiz BC V0M 1A0; [email protected] concentrations of ascorbic, citric, malic, oxalic, fumaric, pyroglutamic, Xiao Wu and/or shikimic acids, and sucrose, glucose and fructose. Genes that Agriculture and Agri-Food Canada, Agassiz, BC; [email protected] influence flavor quality in Capsicum are being identified by analysis of intra- and inter-specific populations. Phenotypic characterization of Glenn Block over 250 Capsicum accessions and select inbred backcross populations Agriculture and Agri-Food Canada, Agassiz, BC; [email protected] should provide breeding material for development of C. annuum stocks In a previous study we reported the effect of different hydrogen perox- with enhanced fruit flavor. ide (H2O2) concentrations (100 mM to 500 mM) on root growth, shoot height and leaf antioxidant activity in pepper seedlings (HortScience Specified Source(s) of Funding: USDA–ARS 43 (4): Abstr. 276). The study showed that in 100mM treatment, shoot (94) Chilling and Heating Induced Antioxidant height was unaffected and the leaf catalase (CAT), peroxidase (POD) POSTERS–Monday Responses in Tomatoes and superoxide dismutase (SOD) activities were higher or similar to control indicating that it may be possible to enhance the antioxidant Yoshihiro Imahori content and hence the nutrient quality of pepper with H2O2 treatment Osaka Pref University School of Agric., Osaka 599-8531; imahori@plant. without damaging the crop. In the present investigation we fed 15 mM osakafu-u.ac.jp H2O2 to two varieties (Red-4Ever-Enza Zaden and Yellow-Bsalga-RZ) Jinhe Bai of mature fruit bearing pepper plants grown hydroponically in bags USDA–ARS, Citrus & Subtropical Products Lab, Winter Haven, FL; filled with sawdust. One week following H2O2 treatment fruits were [email protected] harvested and transferred to cold storage kept at 10 °C. Fruits were Elizabeth Baldwin* examined for visual fruit quality and the antioxidant content in pericarp USDA–ARS, Citrus & Subtropical Products Lab, Winter Haven, FL; liz. tissue at harvest and during cold storage. Visual fruit quality was rated [email protected] from 0 to 5 (0 = no decay, 1 = signs of decay, fungal spores on fruit The ascorbate-glutathione cycle maintains the level of ascorbic acid in stalk, 2 = fungal spores on fruit surface, 3 = first lesion on pericarp the stroma to scavenge hydrogen peroxide, thus protecting the plant from with widespread spore damage (unmarketable), 4 = multiple lesions, oxidative damages. The objective of this research was to determine the 5 = rot and watery). The antioxidant enzyme activity was determined antioxidantive responses to chilling and heating stresses in tomato fruits. using 15-mm diameter pericap tissue harvested and frozen immediately Tomatoes cv. ‘Sanibel’ were harvested at the mature-green stage from in liquid nitrogen. The isoenzymes profiles of POD and SOD were in late June, 2008. Fruit were stored at 20 °C until ripe. Fruit were then also separated by non-denaturing polyacrylamide gel-electrophoresis. treated with either chilling, hot water, or left untreated as the control. Average visual fruit quality was better in fruits from H2O2-treated Fruit samples were taken directly after treatment or after 4 days storage plants up to 21 days of storage at 10 °C compared to control. The two at 20 °C. For each sample, the pericarp was collected from 2-4 fruit, cultivars differed in antioxidant enzyme activity with respect to H2O2 rapidly frozen in liquid nitrogen and stored at -80 °C until analysis. For treatments. For example, catalase (CAT) activity in the fruit pericarp analysis of enzymatic activities, samples were extracted using Tris-HCl tissue from H2O2-treated plants in yellow variety was significantly buffer, and for analysis of substrates and products, 6% TCA was used higher than that of red variety. CAT activities were reduced significantly for extraction. Directly after treatments, heating remarkably increased in both varieties at one week of storage at 10 °C. The POD activity in the activity of lipoxygenase, and chilling increased malondialdehyde red fruit pericarp was slightly higher than that of yellow fruit. Similar content. LOX catalyzes the oxidation of lipids, and MDA is a toxic to catalase, SOD was higher in yellow fruit pericarp tissue than in red compound produced from lipids by oxidative damages. The increase fruit pericarp tissue. The SOD activities in both red and yellow fruit of LOX activity and MDA content indicates oxidative stress caused by pericarps were reduced by H2O2 treatment. the reactive oxygen species. The heat treatment also reduced ascorbic Specified Source(s) of Funding: Federal competitive and dehydroascorbic acid levels, although it induced the activities of peroxidase, catalase, dehydroascorbate reductase, and glutathione (96) Role of Light Emitting Diode (LED) in Negating reductase. After 4 days storage at 20 ºC, antioxidant reductive capacity Needle Drop in Balsam Fir (Abies balsamea L.) was significantly higher in the heat treated fruit than in the control. R. Scott Veitch Chilling directly increased MDA level and decreased ascorbate level, Nova Scotia Agricultural College, Truro, NS; [email protected] and led to a remarkable increase in hydrogen peroxide and MDA on day

HORTSCIENCE, VOL. 44(4), JULY 2009 1141 Rajasekaran Lada* xylem pressure potential (XPP) for each experiment and were submitted Nova Scotia Agricultural College, Truro, NS; [email protected] to an analysis of variance (ANOVA) to detect significant differences. Contrary to our expectations, short-term exposure to ethylene delayed Balsam fir (Abies balsamea L.) is the principle Christmas tree species needle abscission. A concentration of 1000 ppm ethylene significantly grown in Atlantic Canada. It is preferred by consumers for its unique (P < 0.05) increased NRD by 80%, but had no effect on WU or XPP. fragrance as well as its soft needle characteristics. In Atlantic Canada, Long-term exposure to ethylene, however, accelerated needle abscis- the industry is valued at approximately $72 million annually. How- sion. Branches continuously exposed to 1000 ppm ethylene began ever, early harvesting practices, in combination with the occurrence of losing needles on day 5 and completed needle shed was observed on warm fall temperatures in late October, are suspected to have severely day 14, compared to day 35 for the control. There was a 60% decrease deteriorated the needle retention qualities of Balsam fir. Light has a in NRD and 160% decrease in XPP as a result of long-term exposure to significant role in altering the growth and development of plants. This ethylene. Also, daily water use increased after day 5 in those branches includes negating senescence as leaves kept in the dark, senesce faster exposed to ethylene. Overall, the results suggest that ethylene may be compared to the ones that are exposed to light. There is no information the signaling molecule to induce needle abscission in Balsam fir. It relating to the role of various LED spectrums on needle senescence is also suggested that short-term exposure to ethylene might help to and abscission in balsam fir. If any of the LED spectrums could pro- precondition Balsam fir and delay needle abscission. vide a control, then this would allow the use of LED technology to illuminate each of the trees post harvest, through shipment or at home (98) Estimation of the Flesh Texture of Watermelon to control needle loss. The objective of the experiment was to expose balsam fir branches to various spectrums of LED lights at various time Fruits Using Elastic Surface Waves exposures. Two year old branches were collected from Tree Breeding Takashi Ikeda* Centre, Department of Natural Resources, Debert, NS (45º 25’ N, 63º Meiji University, Kawasaki 214-8571; [email protected] 28’ W). Branches were placed in custom built chambers that contain Pak-Kon Choi LEDs emitting red, blue and white spectrum. Control treatments were Meiji University, Kawasaki 214-8571; [email protected] exposed to normal growth chamber lights and a dark treatment was Ikko Arai included. Branches were left in the chambers at 1, 4, 8, 12, 24, and 48 Meiji University, Kawasaki 214-8571; [email protected] hours and after exposure were returned to growth chamber conditions. Masako Osawa Branches were monitored for water use and needle loss daily. Branches Hagihara Farm Co., LTD, Shiki, Nara 636-0222; [email protected] expose to red and white lights at the 12 hour exposure had significantly higher needle retention days (NRD) than other treatments. NRD for We developed a technique for measuring the texture of watermelon red and white treatments were between 65 to 75 days compared to the (Citrullus lanatus) flesh using elastic surface waves. The surface 50 to 55 days for the other treatments. There was little difference in waves were created by the vibration of an oscillator attached to the NRD at the 1, 4 or 8 hour exposures for any spectrum. Overall, the red fruit’s flesh, which transmitted the vibration along the surface of the and white spectrums tend to have more of an effect on NRD at the 12, flesh until it could be detected by an oscilloscope attached to a PZT 24 and 48 hour exposures. bimorpfh actuator. Wave velocity increases with increasingly crisp texture. The velocity of the elastic surface waves along the flesh of the (97) Ethylene Modulates Needle Abscission in Japanese watermelon “Matsuribayashi 777” variety was faster than that Root-detached Balsam Fir of the Japanese “Wase-nissho” variety. In a sensory evaluation, panel members reported that “Matsuribayashi 777” had firmer texture than Mason T. MacDonald “Wase-nissho”, confirming the results obtained using elastic surface Nova Scotia Agricultural College, Truro, NS; [email protected] waves. Our results suggest that it is possible to estimate the texture of Rajasekaran Lada* watermelon flesh using elastic surface waves. Nova Scotia Agricultural College, Truro, NS; [email protected] Alex I. Martynenko (99) Quality and Shelf Life of Grape and Cherry Nova Scotia Agricultural College, Truro, NS; [email protected] Tomato Varieties for Farm-to-School Programs Martine Dorais Penelope Perkins-Veazie* Université Laval, Quebec City, QC; [email protected] North Carolina State University, Kannapolis, NC; penelope_ Steeve Pepin [email protected] Université Laval, Quebec City, QC; [email protected] Billy Roberts Yves Desjardins Lane, OK; [email protected] Université Laval, Quebec City, QC; [email protected] Shelia Magby Post-harvest needle loss is a major problem for the Atlantic Canada’s USDA–ARS, Lane, OK; [email protected] Balsam fir Christmas tree and greenery industry. While the exact physi- Wyatt O’Hern ological trigger is not known, evidence from other herbaceous plants Lane, OK; [email protected] indicate that ethylene, a plant hormone, has been strongly suggested to Cherry and grape tomatoes can be served at U.S. public schools and induce abscission. It is not known, however, whether ethylene triggers colleges with a minimum of preparation. Further, they can be grown, post-harvest needle loss in Balsam fir. It was hypothesized that ethylene harvested, and sold locally and are suitable for protected culture systems. induces abscission in Balsam fir and the intensity of needle loss relates A total of 80 tomato varieties, including yellow, orange, brown, and red to endogenous levels of ethylene. Two experiments were conducted to types, were grown in 2007 and 2008 at Lane, OK, and evaluated for test the effects of ethylene on needle abscission, referred to as short-term fresh use suitability and storage life. The best fruit sizes for children and long-term. In the short-term experiment branches were exposed and adults had individual weights of 10 to 20 g for grape types, and to ethylene at concentrations ranging from 0 ppm to 2000 ppm for 24 15 to 30 g for cherry types. The soluble solids content ranged from h. In the long-term experiment branches were exposed to 1000 ppm 5% to 8%. In red tomatoes, lycopene values ranged from 35 to 120 ethylene daily and compared to an untreated control. The response mg/kg, with total lycopene content generally higher in smaller fruited variables were needle retention duration (NRD), water use (WU), and types. Three varieties were found to be free of decay after 7 days at

1142 HORTSCIENCE, VOL. 44(4), JULY 2009 20 °C, while ‘Gold Nugget’ had symptoms of chilling injury after 7 Nova Scotia Agricultural College, Truro, NS; [email protected] days storage at 5 °C. About 15 varieties were found to be suitable in For yield and harvest optimization, forecasting of bulking in carrots size and quality for the farm to school program, and 5 of these could is critical. Despite being controlled by a plethora of eco-physiological be held for short term storage. factors, agro-climatological factors have a unique ability to induce Specified Source(s) of Funding: USDA–ARS and modulate bulking. Modeling the intricacies of this complex re- lationship demands an approach that offers scalability, flexibility and (100) Measurement of CO2 Evolution in a preciseness. Recently, artificial neural network (ANN) is increasingly Multiplexed Flask System used in yield modeling in lieu of multiple linear regressions (MLR) owing to its non-linearity, adaptive learning and diversified algorithm Jason R. Hupp* capabilities. Accordingly, this study evaluated the efficiencies of MLR LI-COR Biosciences, Lincoln, NE; [email protected] and ANN in modeling the bulking and agro-climatological relation- Richard L. Garcia ship. Field trials were conducted in 5 geographical locations in Nova LI-COR Biosciences, Lincoln, NE; [email protected] Scotia, Canada. Carrot cultivar, Topcut was planted at different seed- Rod Madsen ing dates under 3 seeding rates (40, 55, and 68 seeds/ft). Carrots were LI-COR Biosciences, Lincoln, NE; [email protected] harvested at weekly intervals. At each harvest, root girth, height and Dayle K. McDermitt mass measurements were taken. Of all meteorological and selected LI-COR Biosciences, Lincoln, NE; [email protected] agronomic factors, factor analysis deduced growing degree days (base 5 degrees), rainfall (mm) stand count/m, seeding and harvest dates as Carbon dioxide flux serves as a measure of metabolic activity in many principal input parameters. Bulking models were constructed using organisms, and is directly linked to respiratory processes and photosyn- both ANN and MLR techniques. Data from four fields were chosen for thetic assimilation. The measurement of CO flux requires instrumenta- 2 model construction and results from the fifth field were used to test the tion capable of making precise determination of CO concentration in 2 models. The ANN had one input layer, one hidden layer with 6 nodes air. For small samples, such as individual fruit, insects or plant tissues, and one output layer. The model converged after 10,000 epochs and CO flux is determined from chamber-based measurements utilizing an 2 had a r2 of 0.89 with internal validation. The MLRs had p values of open differential or closed transient approach. Measurement systems 0.001 and had a r2 of 0.79. Upon testing with independent field data, using an open differential approach are well suited for tracking temporal both ANN and MLR models predicted bulking rates with root mean variation in CO flux, as the sample has little influence over chamber 2 square error values of 7.35 and 6.90 t/ha. ANN had slightly higher r2 conditions. However, these systems have difficulty measuring small (0.75) than that of MLR (0.72). ANN model showed slightly improved fluxes from small samples. Systems using a closed approach are able POSTERS–Monday precision and higher flexibility over MLR model. to resolve much smaller fluxes from small samples, but are typically limited in measurement length due to transient chamber conditions and (81) Potential Impacts of Engineered Nanoparticles instrument stability. The LI-8100 Automated Soil CO Flux System 2 on Crop Productivity and Quality with the LI-8150 Multiplexer is designed to measure soil CO2 flux from up to sixteen chambers. We describe the underlying theory of, Sijie Lin and modifications to, the LI-8100 Analyzer Control Unit and LI-8150 Clemson University, Clemson, SC; [email protected]

that allow them to measure CO2 fluxes from discrete samples in a mul- Pu-Chun Ke tiplexed flask arrangement. These modifications take advantage of the Clemson University, Clemson, SC; [email protected] key benefits of both open and closed systems. Measurements are made Hong Luo using closed transient approach, allowing small fluxes to be resolved Clemson University, Clemson, SC; [email protected] from minimal sample material. Between each measurement, chambers Nihal Rajapakse* are continuously flushed with ambient air maintaining chamber CO2 Clemson University, Clemson, SC; [email protected] concentration at or near ambient. This allows for autonomous mea- surement of fluxes from multiple samples over extended time periods. Nanotechnology is growing rapidly and increasing number of consumer Data will be presented demonstrating respiration measurements from goods contains engineered nanoparticles (ENPs). Various new prod- detached fruit using this system. ucts with nanoparticles are being introduced and new applications of nanotechnology are being explored. The use of nanotechnology in food Specified Source(s) of Funding: Private (Association, Foundation, and agriculture sector is also growing rapidly. Major food companies Industry) are exploring the use of nanotechnology to develop advanced food packaging and ‘smart’ food products. Similarly, farm applications of nanotechnology are being explored by agriculture related industry to improve the precision of farming operations. With these rapid devel- Crop Physiology/Physiology: opments, release of ENPs into the environment and contamination of Produce Quality irrigation waters may be inevitable. While consumer products contain- Monday, 27 July 2009 12:00–12:45 pm ing ENPs are increasing, very few reports exist to assess the impact of ENPs on ecological systems including plants, wild life, and humans. In preliminary experiments, we observed that pepper and rice seeds (80) A Comparison of Artificial Neural Network absorbed fullerenes (C70 nanocarbon particles) through the seed coat and Multiple Linear Regression Models in during imbibition and as the seedlings grew fullerenes moved through Understanding the Influence of Agro-climatological the vascular system. In rice, fullerenes delayed flowering, reduced seed setting and were transmitted to the next generation plants. We also Factors on Carrot Bulking observed that the roots could take up fullerenes in irrigation water. As Arumugam Thiagarajan* water evaporated through the stomata, fullerenes accumulated at the Nova Scotia Agricultural College, Truro, NS; [email protected] stomatal opening, which could influence gas movement through the Rajasekaran Lada stomata and eventually affect metabolic processes and the productiv-

HORTSCIENCE, VOL. 44(4), JULY 2009 1143 ity. Our work also showed that quantum dots at high concentrations a gas chromatography. In the case of unpolished seeds, the average reduced the photosynthetic ability of algae. Possible implication of contents of aT, bT, gT, dT and total T were 0.18, 0.10, 1.47, 0.19, and nanoparticles on agro ecosystems will be discussed. 1.95 mg/100g, respectively, and those for aT3, gT3, dT3, and total T3 were 0.20, 1.42, 0.17, and 1.79 mg/100g, respectively. Among 8 tested Specified Source(s) of Funding: NSF varieties, unpolished seeds of var. Yulmo-1 exhibited highest total vit E (82) Squalene and Phytosterol Contents in Seeds of content (4.73 mg/100g). In the case of polished seeds, the average con- tents of aT, gT, dT, and total T were 0.13, 1.63, 0.19, and 1.95 mg/100g, Some Korean Adlay (Coix lacryma jobi L.) Varieties respectively, and aT3, gT3, dT3, and total T3 were 0.26, 1.85, 0.21, and Shiva Ram Bhandari 2.33 mg/100g, respectively. Highest vit E content could be observed Soonchunhyang University, Asan; [email protected] in var. Johyeon (5.13 mg/100g), which showed highest gT, dT, and Suk-Keun Park aT3 contents compared to other varieties. Unlike the unpolished case, Konkuk University, Seoul; [email protected] no bT could be observed in polished adlay seeds in all tested varieties Sunita Basnet under our experimental conditions. In most varieties no significant Soonchunhyang University, Asan; [email protected] difference in total vit E content could be observed between polished Young-Cheol Cho and unpolished seeds, while var. Johyeon showed significantly lower Gyeonggi Agricultural Research and Extension services (GARES), Hwa- total vit E content in unpolished seeds (3.17 mg/100g) compared to song; [email protected] polished seeds (5.13 mg/100g). Young-Sang Lee* Specified Source(s) of Funding: BioResources Innovation Center Soonchunhyang University, Asan; [email protected] To characterize phytonutrient compounds in adlay (Coix lacryma Genetics/Germplasm/Plant Breeding: jobi L.) plants, 8 adlay varieties commonly cultivated in Korea were Marker Assisted Selection in Vegetable Crops collected and their unpolished and polished seeds were used for quantification of squalene and phytosterols: campesterol, stigmasterol Monday, 27 July 2009 12:00–12:45 pm and sitosterol. In the case of unpolished seeds, squalene, campesterol, stigmasterol and sitosterol contents ranged from 2.01 to 7.44, 5.49 to (319) Pyramiding QTL Conditioning Partial 10.23, 7.6 to 18.04, and 20.72 to 40.26 mg/100g, respectively, with an average of 4.12, 8.04, 13.11, and 31.34 mg/100g, respectively. The Phenotypic Resistance to Sclerotinia sclerotiorum highest squalene, stigmasterol and sitosterol contents could be observed Into a Bush Blue Lake Green Bean (Phaseolus in var. Youlmu-1, while highest campesterol could be observed in var. vulgaris) Background Pungsung. Similarly, in polished seeds, average squalene, campesterol, M. Barrett* stigmasterol and sitosterol contents were 4.45, 7.81, 12.04, and 35.66 Oregon State University, Corvallis, OR; [email protected] mg/100g, respectively and their amounts ranged from 3.04 to 7.81, J. Davis 6.34 to 10.8, 8.61 to 17.8, and 28.27 to 59.3 mg/100g, respectively. Oregon State University, Corvallis, OR; [email protected] The highest squalene, campesterol, and sitosterol content were found in var. Aewon and highest stigmasterol was observed in var. Sanggang. S. Zimmerman No significant differences could be observed between polished and Oregon State University, Corvallis, OR; [email protected] unpolished seeds in all tested varieties and compounds, except for var. J.R. Myers Johyeon, which showed higher sitosterol (35.99 mg/100g) in polished Oregon State University, Corvallis, OR; [email protected] seeds than unpolished case (26.37 mg/100g). White mold caused by Sclerotinia sclerotiorum (Lib.) de Bary is a Specified Source(s) of Funding: BioResources Innovation Center necrotrophic pathogen capable of causing severe infection in common bean. White mold is of particular concern to the Oregon vegetable (83) Variation in Tocopherol and Tocotrienol processing industry, where processors allow less than 3% incidence Contents in Some Koean Adlay (Coix lacryma jobi in harvested shipments. Breeding for white mold resistance in beans L.) Varieties has been difficult due to quantitative inheritance and low heritability. We pyramided two QTL for physiological resistance to white mold; Suk-Keun Park a B7 QTL from G122 and a B8 QTL from NY6020. The B7 QTL is Konkuk University, Seoul; [email protected] linked to phaseolin for which a SCAR marker (PHAS) has been used Shiva Ram Bhandari successfully to transfer the QTL in dry bean. The transfer in snap bean Soonchunhyang University, Asan; [email protected] is more challenging because this QTL is also linked to the p which Sunita Basnet conditions white seed. While most snap beans have T-phaseolin, the Soonchunhyang University, Asan; [email protected] OSU bush blue lake (BBL) materials have S-phaseolin, facilitating the Young-Cheol Cho use of T-phaseolin as a selectable marker. Simultaneously, the linkage Gyeonggi Agricultural Research and Extension Services (GARES), between colored seed and the resistance QTL must be broken. The Hwasong; [email protected] B8 QTL is linked to the SS18.1650 SCAR and AW19.1200 RAPD Young-Sang Lee* markers. Oregon State University BBL bean germplasm originally Soonchunhyang University, Asan; [email protected] developed with single QTL of interest were crossed in order to pyramid the two resistance QTL. The assumptions made in combining these two Vitamin E is a well known antioxidant compound commonly found in sources of resistance are that the QTL are non allelic and are additive. seeds of cereals crops. To quantify vitamin E contents in adlay (Coix OSU 6229, 6230, and 6241 are all advanced breeding lines that have lacryma jobi L.) seeds, 8 different varieties generally cultivated in the SS18.1650 allele from NY6020 and show statistically significant Korea were selected and the contents of vitamin E isomers: alpha (a)-, higher levels of resistance in the field and straw test compared to sus- beta (b)-, gamma (g)-, and delta (d)- tocopherols (T) and tocotrienols ceptible cultivars. White seeded, T phaseolin types were selected out (T3) in both polished and unpolished seeds were measured by using of a 91G* × G122 BC2F3 population. The selected lines showed levels

1144 HORTSCIENCE, VOL. 44(4), JULY 2009 of resistance significantly better than the susceptible check cultivars Hye Y. Hwang in the straw test. The two sources were crossed and the progeny were Texas A&M University, Weslaco, TX; [email protected] subjected to three or more generations of phenotypic recurrent selec- Eun M. Lee tion. Sixty-eight F4:6 families and 74 F5:7 families were planted in Chungnam Agricultural Research & Extension Service, Yesan; three blocks using an RCBD design. All families had been previously [email protected] genotyped using the PHAS and SS18.1650 SCAR markers. Plants Kevin M. Crosby were inoculated using active mycelium of S. sclerotiorum and scored Texas A&M University, Weslaco, TX; [email protected] using a modified straw test ranking to test for genetic additivity among marker classes. Results to date show that while lines with markers for Ascorbic acid, also known as vitamin C, is an important fruit quality both QTL possess similar resistance levels to the resistant parents, trait in melon (Cucumis melo L.). Our objectives were to identify RAPD none are significantly more resistant. This suggests that assumptions and andromonoecious (a) markers associated with QTL for ascorbic of additivity of these two QTL may not be correct. acid in an existing molecular linkage map constructed by means of an F2 greenhouse population from the Deltex (high ascorbic acid) x (320) Mapping of QTL Controlling Ananas Melon TGR1551 (low ascorbic acid) cross, and confirm the associations of Fruit Net Formation RAPD and flower markers with QTL for the trait in an F2 field popula- tion from the same cross. Four markers on linkage groups 5 and 6 of Soon O. Park* the linkage map previously were reported to be associated with two Texas A&M University, Weslaco, TX; [email protected] Dulce-derived QTL for ascorbic acid. Thus, our additional goal was Hye Y. Hwang to determine the relationship of the Deltex- and Dulce-derived QTL Texas A&M University, Weslaco, TX; [email protected] to discern common and different QTL for ascorbic acid. A continu- In K. Ham ous distribution for ascorbic acid was observed in the greenhouse Chungnam Agricultural Research & Extension Service, Yesan; and field populations, indicating that the trait was quantitatively [email protected] inherited. Ascorbic acid was positively correlated with sucrose and Kevin M. Crosby total soluble solids, whereas it was negatively correlated with glucose. Texas A&M University, Weslaco, TX; [email protected] A total of 29 RAPD and andromonoecious markers were found to Melon (Cucumis melo L.) net formation traits are composed of net be significantly associated with QTL affecting ascorbic acid in the height, net width, and overall net coverage. Our objective was to greenhouse population based on simple linear regression. Fourteen identify RAPD and phenotypic markers linked to QTL controlling net markers were amplified from Deltex, while 15 markers were obtained POSTERS–Monday height, net width, and overall net coverage in an F2 population from from TGR1551. Six markers associated with QTL on five linkage the cross of Deltex (net presence) × TGR1551 (net absence) grown in groups of the map were significant in a stepwise multiple regression a greenhouse. These markers linked to QTL for net formation traits analysis, and accounted for 30% of the total ascorbic acid variation.

could then be placed in a genetic linkage map constructed using the F2 Sixteen RAPD markers were confirmed in the field population to be population of the cross. Continuous distributions for fruit net formation consistently associated with QTL for ascorbic acid. We found only one were observed in the population indicating quantitative inheritance for common Deltex- and Dulce-derived QTL for ascorbic acid on linkage the traits. Net height was positively correlated with net width and overall group 5. These markers, along with an additional four Deltex- and net coverage. We also found a positive correlation of net width with three TGR1551-derived markers on linkage group 5, could be useful overall net coverage. A total of 42 RAPD markers, 25 obtained from for marker-assisted selection to increase levels of ascorbic acid in Deltex and 17 obtained from TGR1551, were identified to be signifi- new melon cultivars. cantly associated with QTL controlling net height in the population in Specified Source(s) of Funding: This research was funded in part by the greenhouse based on simple linear regression and interval mapping. USDA Grants: 2001-34402-10543, 2003-34402-13647, and 2004- These markers explained 4% to 19% of the net height variation. Six 34402-14768, “Designing Foods for Health” markers associated with QTL on four linkage groups of the map were significant in a stepwise multiple regression analysis, and accounted for (322) Molecular Mapping of RAPD Markers and 42% of the total net height variation. Thirteen Deltex-derived markers Andromonoecious Associated with QTL for Days to on five linkage groups were significantly associated with QTL affect- ing net width in this population. Markers associated with five QTL Harvest in Ananas Melon explaining 24% of the total variation for net width were significant Soon Park* in the stepwise multiple regression analysis. Fourteen Deltex- and 13 Texas A&M University, Weslaco, TX; [email protected] TGR1551-derived markers were associated with QTL for overall net Hye Y. Hwang coverage in the population. Six markers on four linkage groups associ- Texas A&M University, Weslaco, TX; [email protected] ated with QTL for overall net coverage were significant in the stepwise Kevin M. Crosby multiple regression analysis where the full model explained 31% of Texas A&M University, Weslaco, TX; [email protected] the total variation. Particularly, Deltex-derived markers OC14.1400 and OA09.300 on linkage group 7 were associated with all three net Our objective was to identify RAPD and floral markers associated with traits. These markers are expected to be useful in melon breeding for QTL for days to harvest in a genetic linkage map recently constructed controlling fruit net formation. with an F2 population from the melon cross of Deltex (early maturity) × TGR1551 (late maturity) grown in a greenhouse. Marker-QTL as- Specified Source(s) of Funding: This research was funded in part by sociations would then be confirmed for this trait in an F population USDA Grants: 2001-34402-10543, 2003-34402-13647, and 2004- 2 from the same cross in a field. Previously, we mapped QTL for fruit 34402-14768, “Designing Foods for Health” size and shape, seed size and quantity, sugars, and disease resistance (321) Mapping of QTL Affecting Ascorbic Acid in on the linkage map. Thus, our additional goal was to determine the relationship between these newly identified QTL and the previously Ananas Melon mapped QTL for the traits. A continuous distribution for days to harvest Soon Park* was found in the populations indicating quantitative inheritance for Texas A&M University, Weslaco, TX; [email protected]

HORTSCIENCE, VOL. 44(4), JULY 2009 1145 the trait. We noted positive correlations of days to harvest with other fruit size and quality traits including fruit weight, flesh weight, seed Horticultural Crops Culture and Management: cavity weight, total soluble solids, and glucose. Nine RAPD mark- Floriculture Crops 2 ers, located on linkage groups 1, 4, 6, and 10 of the Deltex map, were detected to be significantly associated with QTL for days to harvest in Monday, 27 July 2009 12:00–12:45 pm the F2 population in the greenhouse based on simple linear regression. Six unlinked markers on the Deltex map explaining 30% of the total (187) Chemical Properties Over Time of Root variation for the trait were significant in a stepwise multiple regression analysis. Eleven RAPD and andromonoecious markers on linkage Substrates Containing Increasing Amounts of groups 3, 4, 5, 6, and 10 of the TGR1551 map were significantly as- Growstones, Perlite, and PBH sociated with QTL for days to harvest in the greenhouse population. Michael Evans* Six TGR1551-derived markers, including andromonoecious, were University of Arkansas, Fayetteville, AR; [email protected] significant in the stepwise multiple regression analysis, and explained 44% of the total variation for days to harvest. Of the 20 markers for Growstones are a light-weight aggregate produced from waste glass and days to harvest on six linkage groups of the map, 12 were consistently designed to function as an alternative to aggregates such as perlite and expressed in our populations under greenhouse and field environments. parboiled rice hulls (PBH) in providing for drainage and air-filled pore The andromonoecious locus on linkage group 4 was also associated space in root substrates (substrates). Growstones-containing substrates with five fruit size and shape traits as well as five fruit sweetness traits. had a higher pH than equivalent perlite- and PBH-containing substrates. Two regions on linkage groups 6 and 10 for day to harvest were also The pH increased as the amount (10% to 30%) of Growstones increased associated with all comprehensive sugar traits and four fruit size and as well as over time (0 to 8 weeks) in a greenhouse environment. All shape traits, respectively. These RAPD and floral markers mapped Growstones-containing substrates had a pH within acceptable limits and confirmed here can be useful in breeding to develop different ranging from a low of 5.7 for 10% Growstones after 0 weeks to a high maturity class melon cultivars. of 6.9 for 30% Growstones after 8 weeks. Across time, Growstones-con- taining substrates had electrical conductivies ranging from 0.23 to 0.47 Specified Source(s) of Funding: This research was funded in part by mS/cm which were within recommended ranges for unused substrates. USDA Grants: 2001-34402-10543, 2003-34402-13647, and 2004- The ammonium and nitrate concentrations of Growstones-containing 34402-14768, “Designing Foods for Health” substrates ranged from undetectable to 1.75 ppm and 16.3 to 43.5ppm, respectively. There were no consistent differences in ammonium and nitrate concentrations between Growstones-containing substrates and (323) Automated Design of PCR Primers and equivalent perlite- or PBH-containing substrates. Growstones-contain- ing substrates had higher sodium concentrations than equivalent per- Polymorphism Discovery for Marker-Assisted lite- and PBH-containing substrates. Sodium concentrations increased Selection in Tomato with increasing amounts of Growstones and across time. However, Jeremy Edwards* sodium concentrations (25 to 229 ppm) were within recommended University of Florida, Wimauma, FL; edwardsjd@ufl.edu ranges. After 0 weeks, Growstones-containing substrates had higher Mehul Bhakta silica concentrations than equivalent perlite- and PBH-containing substrates, but after 4 and 8 weeks, Growstones-containing substrates University of Florida, Wimauma, FL; bhaktamehul@ufl.edu had higher silica concentrations than only equivalent perlite-contain- The objective of this project is to generate a set of well distributed ing substrates. Phosphorus, potassium, calcium, magnesium, sulfur, molecular markers for whole genome selection in tomato breeding and micronutrient concentrations were within acceptable ranges for lines. This was accomplished using the current assembly of the tomato all Growstones-containing substrates and times. genome sequence to design markers with known genomic positions. Several checks for uniqueness were done to obtain PCR primers that (188) Physical Properties of a Processed Dairy produce a single band with a high success rate. The assembled sequence Manure Product Used as a Greenhouse Root was masked to exclude known repeats and blasted against itself to mask Substrate Component non-unique sequences. The filtered sequences were divided into seg- ments of approximately 100 kilobases and, where unmasked sequence Elmer Roldan Salazar* was available, PCR primer pairs were designed for each segment. University of Arkansas, Fayetteville, AR; [email protected] Python scripts were used as a final check to ensure that the primers Michael Evans match unique sequence and iteratively search for additional primer University of Arkansas, Fayetteville, AR; [email protected] pairs when the uniqueness check fails. Primers were excluded that had The branded product Nature’s Natural (NN) is a double composted blast hits to the assembled genome sequence greater than 75 percent of diary manure-based product designed to serve similar functions in their length or hits matching the last five bases on the 3’ end. A total greenhouse root substrates as sphagnum peat (peat). When physical of 480 primer pairs were synthesized and tested for amplification of properties of NN were determined and compared with peat, the total a single band on the reference genotype. The primer pairs with single pore space of the peat was 86% (by vol.) while the total pore space of band amplification were used on a panel of fresh market tomato lines. NN was 87%. Air-filled pore space for peat and NN was 12.9% and The PCR products were pooled and SNPs were detected by ecotilling 12.3%, respectively. Water-holding capacity was 73% and 75% for peat with Cel I enzyme. Amplicons from primer pairs where SNPs were and NN, respectively. Bulk density was 0.09 and 0.10 g·cm-3 cm for detected were sequenced and cleaved amplified polymorphic sequence peat and NN, respectively. Root substrates containing NN generally (CAPS) markers were designed and validated. had similar physical properties as the respective peat-based control Specified Source(s) of Funding: USDA root substrate. Physical properties of all NN-containing root substrates were within commonly recommended ranges. The NN lost water at a lower rate than peat and root substrates containing NN lost water at a lower rate than the peat control root substrate. The NN required more

1146 HORTSCIENCE, VOL. 44(4), JULY 2009 days to dry to the 50% (by vol.) moisture level and the complete drying for NI and CL, respectively. Temperature was optimum for cyclamen level than peat. Root substrates containing NN required more days to growth (24/16oC, day/night). NI and CL treatment hastened flowering dry to the 50% moisture level and the complete drying level than the in both Cyclamen persicum SR and SP. Cyclamen persicum SR and peat control root substrates. SP reached flowering maximum 19 and 12 days, respectively, earlier than plant grown at SD condition. There was no significant difference (189) Growth of Vinca and Geranium in in flowering time of both SR and SP among light sources at each NI Growstones-, Perlite-, and PBH-Containing and CL. There was no significant difference in the number of visible Root Substrates buds and flowers among light treatments and light sources. However, plant length and width tended to increase at both NI and CL with far- Michael Evans* red LED than those at other LEDs in both SR and SP. The number of University of Arkansas, Fayetteville, AR; [email protected] visible buds significantly decreased at CL with blue LED in SP. In ad- Clint Metcalf dition, the number of flowers at NI with blue LED was less than those University of Arkansas, Fayetteville, AR; [email protected] at NI with red LED. Although, there were some differences between Growstones are a light-weight aggregate produced from waste glass SR and SP, plant grown under NI and CL with far-red and blue LED bottles and containers. They are designed to serve as an alternative to produced poor quality commodities of Cyclamen persicum than those such aggregates as perlite and parboiled rice hulls (PBH) in providing under NI and CL with red LED. Electricity consumption of LED was for drainage and air-filled pore space in root substrates (substrates). about 60% of fluorescent lamp. Fluorescent lamp was widely used at There were no differences in shoot height, shoot dry weight or root dry NI and CL treatment in general. These result indicated that red LED weight of ‘Cooler Grape’ vinca (Catharanthus roseus) plants grown in could replace the fluorescent lamp for promoting cyclamen flowering sphagnum peat-based substrates containing 10% to 30% Growstones, at NI and CL due to electricity cost. For details in cost saving, more perlite or PBH. Vinca grown in all root substrates were of marketable economical analysis is necessary including both investment and operat- quality. Shoot height of ‘Orbit Cardinal Red’ geranium (Pelargonium ing cost of LED lamps in a commercial greenhouse. xhortorum) grown in the 30% Growstones substrate were shorter than Specified Source(s) of Funding: Ministry of Education, Science, and vinca grown in the 30% perlite substrate. No other differences occurred Technology, South Korea in geranium height between Growstones-containing substrates and equivalent perlite- or PBH-containing substrates. Geranium shoot dry (191) Abscisic Acid: A Potential Treatment for weight grown in the 30% Growstones substrate were lower than for Reducing Leaf Wilting in Potted Bedding Plants vinca grown in the 30% perlite substrate. No other differences occurred in geranium shoot dry weight between Growstones-containing substrates H. Brent Pemberton* POSTERS–Monday and equivalent perlite- or PBH-containing substrates. Root dry weight Texas AgriLife Res & Ext Ctr, Texas A&M System, Overton, TX; b- [email protected] of geranium grown in the 10% Growstones substrate was higher than for geranium grown in the 10% PBH substrate, but root dry weight Andrew J. Macnish of geranium grown in the 15% Growstones substrate was lower than University of California, Davis, CA; [email protected] for geranium grown in the 15% PBH substrate . No other differences Michael S. Reid occurred in geranium root dry weight between Growstones-containing University of California, Davis, CA; [email protected] substrates and equivalent perlite- or PBH-containing substrates. Plants Cai-Zhong Jiang of vinca and geranium grown in substrates containing 10% to 30% University of California, Davis, CA; [email protected] Growstones were of marketable quality. William R. Roberson Texas AgriLife Res & Ext Ctr, Texas A&M System, Overton, TX; w- (190) Night Interruption and Cyclic Lighting Using [email protected] LEDs Promote Flowering and Save the Production Water deficit stress during postproduction transport and marketing Cost of Cyclamen in Winter reduces the saleability of many bedding plants. This problem arises Jong Hwa Shin from excessive water loss during extended periods of shipping at el- Seoul National University, Seoul 151-921; [email protected] evated temperatures and limited watering of plants during subsequent Hyun Hwan Jung retail display. In the present study, we evaluated the efficacy of abscisic Seoul National University, Seoul 151-921; [email protected] acid (ABA) treatment to reduce the visible effects of water stress in Hyun Jin Kim potted flowering New Guinea Impatiens and zonal Geraniums. In the Seoul National University, Seoul 151-921; [email protected] first experiment, plants at commercial maturity were sprayed to runoff with 0, 5, 10, 20, 50 and 100 mg·L-1 ABA and subjected to simulated Bo Kyung Kang shipment in boxes for 2 days at 20 °C. In a second experiment, plants Seoul National University, Seoul 151-921; [email protected] were sprayed with 100 mg·L-1 ABA prior to simulated shipment or Ki Sun Kim* an actual 3-day commercial shipment between Overton, Texas and Seoul National University, Seoul 151-921; [email protected] Davis, California. All plants were watered once after shipment and Night interruption (NI) and cyclic lighting (CL) are used as an alterna- then were held at 20 °C for 4 weeks for evaluation of treatment re- tive method to heating for promoting cyclamen flowering. This study sponses. Treatment with ABA greatly delayed the onset to visible leaf was conducted to investigate the effect light quality during NI and CL wilting for impatiens but not for geranium. ABA treatments were not on flowering. Two species of cyclamen [Cyclamen persicum ‘Scarlet phytotoxic to plants and did not affect flower longevity. Our findings Red’(SR) and ‘Scarlet Purple’(SP)] were grown under four different provide support for expanded testing of ABA and other osmoticums as light sources (fluorescent, red LED, far-red LED, blue LED) with com- a potential postproduction treatment to delay leaf wilting in bedding bination of NI (4 h) and CL (6’/24’ on/off for 4 h) around midnight in a plant species. The authors would like to acknowledge funding from growth chamber. Short-day (SD) was 9 h. Photosynthetic photon flux the Federal IR4 Program. was 300 µmol·m-2·s-1 with three-wave fluorescent lamp during day time Specified Source(s) of Funding: IR4 and 3-15 µmol·m-2·s-1 with fluorescent lamp and LEDs of each wave

HORTSCIENCE, VOL. 44(4), JULY 2009 1147 (192) Fertilizer Requirement of Phalaenopsis During plant quality ratings during the landscape performance evaluation was Reproductive Stages similar to that found in growth of the greenhouse grown plants during the first 4 weeks. However, these differences disappeared during the Hsin-Yi Lei remainder of the study. National Taiwan University, Taipei 10617; [email protected] Yao-Chien Alex Chang* National Taiwan University, Taipei 10617; [email protected] Horticultural Crops Culture and Management: Viticulture and Small Fruits In order to understand the effects of different concentrations of nitrogen, phosphorus, and potassium on flower quality and vegetative growth of Monday, 27 July 2009 12:00–12:45 pm Phalaenopsis amabilis, we treated mature plants with different nutrient solutions for two flowering cycles. During the first flowering cycle, (229) Does Drying Temperature Affect Grape Leaf flowering and flower quality were not affected by fertilization treatments; however, total leaf areas and number of new leaves were increased as Nitrogen and Carbon Concentration? the concentrations of nitrogen (0, 7.1, 14.3, 21.6 mM) and potassium Joan R. Davenport (0, 2.1, 4.2, 6.4 mM) increased. Phosphorus concentration at 2.1 mM WSU Prosser, Prosser, WA; [email protected] decreased shoot weight and increased leaf abscission. Increasing potas- Catherine Jones* sium from 0 mM to 6.4 mM increased fresh and dry weight of plants. Washington State University, Pullman, WA; [email protected] Applying 0 mM nitrogen resulted in highest percentage of plants with Mercy A. Olmstead leaf abscission. When nitrogen and potassium concentrations increased, Washington State University, Prosser, WA; [email protected] leaf abscission decreased. During the second flowering cycle, days to spiking, days from spiking to bud visible, and days from spiking to Plant nutrition response studies often report different temperatures and first flowering were not affected by different concentrations of nitrogen, durations for drying plant leaves in preparation for nutritional analysis. phosphorus, or potassium. The concentration of phosphorus had no It is possible that drying temperature could have an effect on the final effect on flower diameter and size. There was a positive relationship nutrient concentration after analysis. During two growing seasons we between the concentration of potassium and stalk diameter or number collected a large bulk sample of wine grape leaves from a commercial of flowers, although there were no differences between the treatments of vineyard at verasion. Leaves were separated into petiole and blade 4.2 and 6.4 mM potassium. Increasing nitrogen concentration increased fractions in the field and the samples were well mixed. Sub samples of total fresh weight, total dry weight, total leaf areas and number of equal volume were dried concurrently at 40, 50, 60 or 70 °C in small newly formed leaves. Less effects were found on the quality of flower drying ovens for 72 hours. Samples were then ground in a Wiley mill. and growth of Phal. amabilis by applying different concentrations of All samples were analyzed for total C and N using dry combustion, phosphorus, compared with those of nitrogen and potassium. In this plus petiole samples were extracted (1:100 wt:vol with DI water) and study, nutrient solution with 14.3 mM nitrogen, 1.4 mM phosphorus analyzed for NO3-N. Drying temperature influenced total C in petioles and 6.4 mM potassium resulted in best flower quality and vegetative in the first year and blades in the second. Total N concentration in growth in Phal. amabilis. blades decreased with increasing drying temperature in the first year and petiole NO3-N increased with increasing temperature in the second Specified Source(s) of Funding: Council of Agriculture, Taiwan [94AS- year. These results demonstrate that drying temperature does influence 5.2.1-ST-a1(1); 95AS-6.2.1-ST-a1(3); 96AS-1.2.1-ST-a1(4)] grape leaf tissue N and C concentrations, suggesting that a standard temperature needs to be established for sample handling. (193) Assessing Biodegradable Containers for Greenhouse and Landscape Performance (230) High Tunnel Strawberry Cropping Systems Jeff Kuehny* Research in West Virginia Louisiana State University, Baton Rouge, LA; [email protected]. Lewis Jett* edu West Virginia University, Morgantown, WV; [email protected] Michael Evans Strawberry (Fragaria ×ananassa) is a popular small fruit crop for high University of Arkansas, Fayetteville, AR; [email protected] tunnel production in many regions of the United States. High tunnels Matthew D. Taylor are unheated passive-solar greenhouse structures which are used to Longwood Gardens, Kennett Square, PA; [email protected] protect the growing crop from environmental stresses and significantly Biodegradable containers are a sustainable product that might be easily extend the growing season. No information is available which examines adapted to floriculture production, provide resource conservation, and high tunnel production of strawberry in the central Appalachian region. excellent marketing opportunities. However, there is little information Several cultivars of June-bearing and day-neutral strawberry cultivars on the feasibility of using these containers in floriculture production were established within high tunnels in north-central and southeast systems or landscape performance. The objective of this research was West Virginia to evaluate winter hardiness, pest spectra, yield and to evaluate the greenhouse and landscape performance of ‘Dreams postharvest quality from 2007–09. Pests were managed using both Midnight’ petunia (Petunia ×hybrida), pansy (Viola xwitrockiana) or beneficial insects and soft pesticides. Early plugging of runners from ‘Citron Yellow’ wall flower (Erysimum allionii) grown in 10 cm round June-bearing cultivars was compared with standard, commercial plugs plastic containers or biodegradable containers composed of peat, wood and some plants were extended for a second year of production. The fiber, or core. The leaf area of pansy was greatest when grown in wood high tunnel structure maintained a significantly greater average daily fiber containers when compared to the plastic or coir containers. How- temperature through the growing season which allowed growth of the ever, the leaf area and dry weight of petunia was greatest when grown plants and flower bud initiation through late fall. Pests were kept below in peat containers compared to the wood fiber containers by 50% and thresholds by using IPM practices within the high tunnel. ‘Chandler’ 40%, respectively. Thus, there appears that there may be a difference in produced more branch crowns and the highest yield per plant and the effect container type has on plant growth based on plant type. There exhibited excellent winter hardiness. Marketable yields ranged from was no effect of container type on growth of wall flower. The results of 363 g to 500 g per plant.

1148 HORTSCIENCE, VOL. 44(4), JULY 2009 (231) Comparative Growth and Development of 0.65 for ‘Bob Gordon’ to 0.54 for ‘Netzer’. When comparing fruit Vines and Fruit of Red Globe Table Grapes on produced on primary or secondary stems, no differences in TSS were detected, however fruit from primary stems had significantly lower pH Harmony and on Its Own Roots (4.76) and higher TA (0.62) compared with fruit from secondary stems L. Antonio Lizana* (pH 4.91 and TA 0.58). Among experimental factors, fruit with more CEPOC University of Chile, Santiago 8829808; [email protected] desirable enological characteristics (lower pH, higher TA, and higher Hugo Sepulveda TSS) was generally produced at Mountain Grove, by ‘Bob Gordon’, CEPOC University of Chile, Santiago 8829808; h.sepulveda.s@hotmail. and on primary stems. Plants at Mountain Grove were more vigorous com and yielded higher than plants at Mt. Vernon, and ‘Bob Gordon’ out- Marcelo Orellana performed the other cultivars in terms of vigor and yield. Fruit from CEPOC University of Chile, Santiago 8829808; [email protected] primary stems is generally borne on single, very large cymes, whereas secondary stems produce more numerous, smaller cymes. As we bet- The use of rootstock for grape vines is recently in Chile, since it is one ter understand how genetic, environmental, and horticultural factors of the few countries filoxera-free, and also due to the prohibition of interact to determine elderberry fruit quality, important production introduction to the country of vitis wood from 1894 until 1978. In the decisions can be made. last 25 years, different root stocks have being introduced and studied in different areas of the table grapes production zones. A trial was Specified Source(s) of Funding: University of Missouri conducted during the 2007–08 season on the comparative growth and development of vines and fruits on Red Globe table grapes on Harmony (233) Effects of Training System on Sunlight roots (21 years old) and on its own roots (19 years old plants) estab- Penetration, Canopy Structure and Fruit lished on the Chilean parron system (trellis) 4 × 3 m. In general, there Characteristics of ‘Frontenac’ (Vitis spp.) were no perceptible differences in most of visual parameters checked Christina Huck* (berry polar and equatorial diameter, berry weigh and volume, number University of Nebraska, Lincoln, NE; [email protected] of seeds, trunk diameter). Nevertheless, vines on Harmony presented longer shoots (average 125 cm length) which gave a slight apparent Elizabeth A. Walter-Shea bigger canopy to the vine, the titratable acidity was always higher dur- University of Nebraska, Lincoln, NE; [email protected] ing the whole period of growth and fruit harvest was a week earlier. Paul Read Foliar (blade) analysis at veraison showed higher levels of K, Ca, Zn, University of Nebraska Dept Hort, Lincoln, NE; [email protected] and Mn and lower B in vines on Harmony than on its own roots. No Trellises or training systems influence many aspects of grapevine growth POSTERS–Monday signs of incompatibility were noticed on vines of this age. and production. This study investigated the effects of 5 trellis styles on Specified Source(s) of Funding: CEPOC (Postharvest Study Center) the fruit-zone light environment, fruit chemical composition and yield of Univ. of Chile ‘Frontenac’ grapes grown on a highly fertile site near Crete, Nebraska. Photosynthetically active radiation (PAR) was measured with a line (232) Characteristics of Elderberry Fruit in quantum sensor (LI-COR Biosciences, Inc., Lincoln, NE) both above Response to Genotype, Environment, and the canopy and within the fruiting zone at 3 stages of fruit development (berry set, veraison, and harvest) from which percent transmittance was Pruning Management calculated. Point quadrat canopy analysis was performed at veraison; Andrew L. Thomas* data were used to compute leaf layer number (LLN). Fruit was collected University of Missouri, Mount Vernon, MO; [email protected] at harvest for chemical analysis (pH, per cent soluble solids, titratable Patrick L. Byers acidity). At all sampling dates, vines grown on Geneva Double Curtain University of Missouri, Springfield, MO; [email protected] (GDC) and High Cordon (HC) trellises had significantly higher mid-day transmittances than vines grown on Smart Dyson (SD) and Vertical American elderberry (Sambucus canadensis L.) is an emerging horti- Shoot Positioned (VSP) training systems. LLN was lower for GDC cultural crop in North America. The native shrub produces fruit that is and HC than for SD and VSP. GDC vines had higher fruit yield (2.4 used to make jams, jellies, beverages, dietary supplements, food color- kg per plant) than VSP, SD, HC, and Scott Henry (1.3, 1.3, 1.1, and 0.9 ing, and wines. Elderberry produces fruit on both new (primary) and kg per plant, respectively). Yields for all trellis styles were lower than old (secondary) stems. Little is known about the characteristics of fruit expected due to wind damage early in the season. GDC fruit had higher produced on these two different types of plant growth, or how genetic pH and soluble solids than fruit from other trellises; titratable acidity and environmental factors affect fruit quality. Replicated elderberry was lower in GDC and HC fruit than in SD and VSP fruit. GDC and orchards were planted at two locations in Missouri (Mt. Vernon and HC canopies had the highest (most favorable) transmittance values, but Mountain Grove) in 2000 for a long-term pruning study. Randomized GDC vines yielded significantly more and better quality fruit. These plots were assigned one of three cultivars (‘Adams II’, ‘Bob Gordon’, results suggest that GDC is the best training system for ‘Frontenac’ on or ‘Netzer’), and one of two pruning regimens (annual removal of all high vigor sites in southeastern Nebraska. shoots, and selective horticultural pruning) so that fruit were produced almost exclusively on either primary or secondary stems. In 2006, ripe (234) Effect of Compost Sources on the Soil Fertility fruit were harvested from each plot and frozen. For analysis, 250 mL and the Behavior of Raising Grape in Caborca, of fruit were thawed, macerated, strained through cheese cloth, and the resulting juice centrifuged at 3,500 rpm for 10 min. Supernatant juice Sonora was analyzed for pH, total soluble solids [TSS (°Brix)], and titratable Fabián Robles Contreras acidity [TA (g 100 mL-1). Fruit harvested from Mountain Grove had INIFAP, Caborca Sonora 83600; [email protected] significantly higher TSS (11.82), lower pH (4.71), and higher TA (0.64), Manuel Valenzuela Ruiz compared with fruit from Mt. Vernon (TSS 11.16, pH 4.98, and TA 0.56). INIFAP, Caborca Sonora 83600; [email protected] Among fruit from the three cultivars, no differences were detected for Raul Grijalva-Contreras* TSS, however pH and TA varied significantly, with pH ranging from INIFAP, Caborca Sonora 83600; [email protected] 4.97 for ‘Adams II’ to 4.73 for ‘Bob Gordon’, and TA ranging from

HORTSCIENCE, VOL. 44(4), JULY 2009 1149 Rubén Macias Duarte (236) Development of Pitanga (Eugenia uniflora L.) INIFAP, Caborca Sonora 83600; [email protected] as a Commercial Crop for Hawaii Fidel Nuñez Ramirez Virginia E. Smith ICA- UABC, Caborca, Sonora; [email protected] University of Hawaii at Manoa, Honolulu, HI; [email protected] The surface destined to produce raising grape in the agricultural area of Ty G. McDonald Caborca, Sonora, represents 44% of the 8000 ha planted with this crop, University of Hawaii at Manoa, Honolulu, HI; [email protected] in addition this is a high demand product, due to the excellent quality Malcolm M. Manners that it have in this region. The high cost of fertilizers combined with Florida Southern College, Lakeland, FL; mmanners@flsouthern.edu innocuity norms that are being implemented, has forced to the search of John L. Griffis* ecological and economically alternatives for the nutrition of the crops, American Society for Horticultural Science, Honolulu, HI; for that reason several sources of compost, two not processed (bovine [email protected] manure, and residue of Olive fruit) and three commercial products Eugenia uniflora (Visur, Remin, and Alta) and the Control treatment without compost, L., (pitanga, Surinam cherry, pitangueira) is native were evaluated to check its effect on the soil fertility, the bub break, the to Brazil and other countries in northern South America. In its native -1 range, this fast-growing shrub or small tree usually produces two crops yield and the quality of the raising grape. 12.5 t·ha of compost were per year of relatively small (2.5 to 3.5 cm), juicy fruits. The fruits ripen applied in January of 2007, and the evaluation was realized during cycle quickly, taking only about six weeks to reach maturity from anthesis. 2008. The results indicate that the soil fertility was improves, being Differing from bush to bush, the mature fruits range in color from increased the organic matter content as well as the Nitrogen, Phospho- orange to red to dark purple. The juicy sweet-acid pulp encloses one rus and Potassium content. Also all the compost sources induced an or occasionally more seeds. The fruits, especially the dark purple ones, increase in the total bud break, where apparently this increase was due are an excellent source of antioxidants such as cyanidin-3-glucoside, to the stimulus in the secondary yolk and on the old wood yolk. As far delphinidin-3-glucoside, the xanthophyll lutein and the carotenoid ly as the yield, all the compost affected positively the Fresh Grape (FG) - -1 copene. The ripe fruits can be eaten fresh or they can be processed into and Raising Grape (RG), whereas the Control yield was 6.9 t·ha and -1 frozen pulp, juices, jams, jellies and other food items. Plants prosper 1.5 t·ha of FG and RG respectively, the compost yield was from 9.9 -1 -1 -1 -1 in soils with abundant organic matter and a pH of 5.5–6.5 although t·ha to 21.1 t·ha FG and 2.5 t·ha to 4.7 t·ha of RG, where Alta and -1 -1 they can grow acceptably in many different situations. The seedlings bovine manure were the high yield with 21.1 t·ha and 20.8 t·ha of -1 -1 establish quickly and produce more heavily and earlier when grown FG and 4.6 t·ha and 4.7 t·ha of RG respectively. in full sun. They are easy to grow without fertilization although they Specified Source(s) of Funding: INIFAP respond very positively to fertilizer and water applications. Plants come into bearing from seed in three to four years, although superior grafted (235) Effect of the Date of Cuts of Irrigation in plants can produce fruits when the grafts are one to two years old. A Postharvest Time on the Productivity and large trial planting of pitanga is in its third year in the ground at the Quality of Superior Seedless for Table Grape University of Hawaii Kona Experiment Station. Fertilizer trials allow in the Region of Caborca, Sonora us to provide organic and non-organic fertilizer recommendations for small-scale producers. We also collect information on fruit yield and Manuel Valenzuela Ruiz fruit size of individual plants. Flowering on any bush is asynchronous, INIFAP, Caborca Sonora 83600; [email protected] with open flowers and ripe fruits often present at the same time; this Fabián Robles Contreras does present some harvest challenges. In the Kona planting, flower- INIFAP, Caborca Sonora 83600; [email protected] ing between individual bushes is also not well synchronized and this Raul Grijalva-Contreras* leads to the possibility of significant year-round production of the crop INIFAP, Caborca Sonora 83600; [email protected] within one field. Additional laboratory analysis on acid, °Brix, and other Rubén Macias Duarte chemical and nutritional contents of mature fruits allow for further INIFAP, Caborca Sonora 83600; [email protected] selection and development of superior clones for Hawaii. Postharvest refrigeration evaluations are also being conducted. Successful grafting Fidel Nuñez Ramirez trials using the improved dark purple cultivar ‘Zill Dark’ yielded good ICA- UABC, Caborca, Sonora; [email protected] results with veneer grafts and a row of ‘Zill Dark’ has been added to In the state of Sonora, grapevine is one of the main crops, due to the the experimental planting for comparison and as a source of budwood. economic special tax that originates and the manpower that generates. Grafted superior local selections from this field will be provided to Between the main problems that presents the producing regions of cooperating growers. the state (Hermosillo and Caborca), specially for the production of Specified Source(s) of Funding: Hawaii Tropical Specialty Fruit Re- table grape, is the shortage of water availability and in spite of this search and Development Grant the tendency is to irrigate and to fertilize more. The objective of the present study was: To determine the effect of the date of watering court (237) Biofumigation of a Strawberry Matted-Row in postharvest on the productive behavior and phonological stages of Site with Brassica Green Manure Cover Crop Superior Seedless cultivar. The evaluated treatments were: cut off the irrigation on: September 15, 30, October 15 and the control on October Martin Kaps* 30. The results indicate not statistical differences between treatment, Missouri State University, Mountain Grove, MO; but we observed a tendency to have earliest and bigger bubreak when [email protected] irrigation cut off is early too, compared with the control (five days John Avery early), also we observed a tendency to present more clusters. However Missouri State University, Mountain Grove, MO; the next year, they were harvested more boxes in the first harvest time [email protected] when the irrigation cut off was early. Patrick Byers Greene County Extension Office, Springfield, MO; [email protected] Specified Source(s) of Funding: INIFAP Brassica napus cultivars ‘Plainsman’, ‘Sumner’ and ‘Wichita’ were

1150 HORTSCIENCE, VOL. 44(4), JULY 2009 seeded in September 2006 on ground that previously grew matted-row students attending a class associated with the Short Course. Results strawberries. These cover crops were used as an alternative to chemi- of 2007 through 2009 evaluations will be presented to determine the cal fumigants prior to replanting the site to strawberries. Control plots impact on the program. (previously and not-previously planted to strawberries) were seeded Specified Source(s) of Funding: OSU Nursery Short Course to Secale cereal, grain rye in October 2006. Soil was a Viraton cherty silt loam with a fragipan in the subsoil, typical for the Ozark region of (18) Microbial Food Safety Training for the Produce Missouri. Both cover crops were incorporated in late March 2007 and strawberries planted in May. The experiment was a split-plot design Industry in New Jersey with four replications. Strawberry cultivars were Allstar, Annapolis, Wesley Kline* Brunswick, Eros and Mesabi. Nematode populations showed no differ- Rutgers Cooperative Extension, Millville, NJ; [email protected] ences in harmful species among treatments. Strawberry crown counts Larry Hardwick showed no differences among treatments for four of the five cultivars. New Jersey Department of Agriculture, Trenton, NJ; larry.hardwick@ag. Only Eros had highest crown counts in the control (not-previously state.nj.us planted to strawberries). Visual canopy rating showed the more vigor- The Food and Drug Administration (FDA) reports that between 1998- ous strawberry plants in this control for all cultivars except Mesabi. 2006 five commodity groups make up 76% of produce related food Total yield showed Sumner and Wichita not different from the control borne illness outbreaks (lettuce/leafy greens—30%, tomato—17%, (previously planted to strawberries). Plainsman had lowest total yield. cantaloupe—13%, herbs—11%, and green onions—5%). In September Average berry weight showed little difference among the treatments. 2006, an E. coli 0157:H7 outbreak in spinach grown in California affected Only the control (not-previously planted to strawberries) had highest the whole produce industry when the FDA stopped sales of spinach average berry weight. The lack of treatment affect for Brassica cover in the United States. New Jersey growers lost over $500,000. Rutgers crops used as biofumigants indicated that damaging nematodes were Cooperative Extension and the New Jersey Department of Agriculture not a limiting factor in this strawberry replant site. developed a food safety program to educate growers and buyers on food safety and what is required to meet the increasing demand from the wholesale industry for a third party audited food program. Thirty- seven workshops and presentations with over 1400 participants were Horticulture Extension held from January 2007 to December 2008. These workshops covered Monday, 27 July 2009 12:00–12:45 pm worker health and hygiene, animal/wildlife and livestock management,

manure and municipal biosolids use, field sanitation, field harvesting POSTERS–Monday (17) Evaluation of Program Changes with the Ohio and transportation, packing house management, storage facilities, pest control and produce traceback. A food safety manual was developed State University Nursery Short Course along with an accompanying CD to address all topics and provide Hannah M. Mathers* documentation logs. Following the workshops growers scheduled on- Ohio State Univ., Hort. & Crop Sci., Columbus, OH; [email protected] site evaluations of their operations prior to having a formal third-party Densie M. Johnson audit. The main problems observed were incomplete records, lack of Ohio State Univ, Hort. & Crop Sci., Columbus, OH; johnson.2924@osu. pest control and proper latrine maintenance. Growers gained better edu understanding of how important food safety is to their operations with the workshops and on-site visits. Fifty-two New Jersey operations The Ohio State University Nursery Short Course (OSU NSC) has been passed the United States Department of Agriculture Third Party Audit providing the green industry with cutting edge educational information, Verification after this program. research updates and innovations for nursery, landscape, garden center, tree care and turf professionals for 80 years. The three sponsors of the Specified Source(s) of Funding: New Jersey Department of Agricul- OSU NSC—The Ohio State University Department of Horticulture and ture Crop Science; OSU Extension Nursery, Landscape and Turf Team; and Ohio Nursery and Landscape Association—work closely together in (19) Intermountain Regional Evaluation and the planning and implementation of this program. On January 25–28, Introduction of Native Plants 2009, 120+ sessions were presented by internationally, nationally and Karen Panter* locally recognized experts and industry leaders to over 2,000 attendees. University of Wyoming, Laramie, WY; [email protected] The OSU NSC, held in conjunction with the Central Environmental Heidi Kratsch Nursery Trade Show (CENTS), was modified in 2007 to establish non- Utah State University, Logan, UT; [email protected] competing hours with CENTS with only morning educational sessions organized into tracks of four 50-minute presentations per track that This project began as a multi-state research project, WDC 011, in 2007 focused on selected topics. In 2009, additional educational sessions and became an official WERA activity in 2008. It incorporates two broad were provided on Tuesday with one afternoon track of four 50-minute objectives. The first is to establish a regional system for development, sessions called “Foundations and Fundamentals.” Also in 2009, all day evaluation, and introduction of new native plant materials and cultivars, educational sessions were provided on Wednesday with the addition of especially plants that facilitate water conservation. The second is to two 50-minute sessions in five tracks in the afternoon. Evaluations of coordinate regional efforts to provide education to both the public and the trade show and Short Course during 2007, 2008 and 2009 indicate industry professionals on native plant propagation/production, water some of program changes have benefited the program and others have conservation benefits and use in ornamental landscapes, and maintenance been detrimental. Attendance for the Short Course has declined by of native-plant-dominated ornamental landscapes for efficiency of water 30% in this three year period and the trade show 31%. Trade shows use. WERA 1013 members will be identifying candidate native plant across the United States have seen dramatic declines in attendance. species, common to some or all states, for further evaluation. Evalu- Also, the economy has factored into people’s decisions to cut back on ation will include suitability for production and growth in the region these types of events. In addition to annual on-site attendee evaluations as well as potential for marketing. It is anticipated that species will which use a Likert scale evaluation tool, data has been gathered from be evaluated for at least three growing seasons at participating sites.

HORTSCIENCE, VOL. 44(4), JULY 2009 1151 Characteristics to be checked will include heat and drought tolerance, feedback from the initial training class of female inmates. cold hardiness, ease of production, invasiveness potential, and limits of environmental adaptation. The group will meet at least annually to share (22) Focus Groups Gain Insights from Spanish- results and plan educational and outreach programs. A website is also speaking Horticultural Workers in Iowa being developed to ease information sharing and increase awareness Cynthia Haynes* about native plant use. Outcomes expected in future years are increased Iowa State University, Ames, IA; [email protected] knowledge of native plants for water-conserving landscapes, increased Emilie Justen knowledge and production of natives by propagators and growers, Ames, IA; [email protected] regional education and outreach programs about native plant concepts, and increased use of water-conserving native plants by landscape pro- Ann Marie VanDerZanden fessionals and the public. New members are welcome! Contact Heidi Iowa State University, Ames, IA; [email protected] Kratsch ([email protected]) or Karen Panter (kpanter@uwyo. Labor-intensive tasks, seasonal positions, low wages, and a decreas- edu) if you’re interested. Membership in WERA 1013 is encouraged ing supply of domestic labor have contributed to horticultural firms in from both public institutions and industry representatives within the Iowa hiring foreign-born workers (Bitsch, 2004; Boucher et al., 2007; Intermountain West. However, no geographic limitations are in place Waliczek et al., 2002). The majority of these workers are Spanish- and all interested parties are encouraged to become official members. speaking Latinos who came to the United States from Mexico and other Currently, members list addresses in Montana, Wyoming, Colorado, parts of Latin America (United States Department of Labor, 2005). The Utah, Idaho, Texas, Alaska, Oregon, and Iowa. objective of this study was to assess the educational, communication, and technical needs and skills of Latino workers in the horticultural (20) Expanding Sustainable and Organic Training industry in Iowa. Three focus groups were conducted with a total Opportunities in Arkansas of 22 Latino workers recruited in cooperation with English-speak- M. Elena Garcia* ing managers. Participants worked primarily in nursery production, University of Arkansas, Fayetteville, AR; [email protected] landscape installation, and golf course maintenance. Spanish-speak- H. Friedrich ing participants cited language barriers, gaps in communicating with University of Arkansas, Fayetteville, AR; [email protected] supervisors, and limited horticultural knowledge as key job challenges. Most participants received on-the-job training from Spanish-speaking Curt R. Rom crew leaders. Spanish-speaking participants were interested in taking University of Arkansas, Fayetteville, AR; [email protected] classes in Spanish about horticultural practices, plant identification, Certified organic production throughout the southern region lags behind and chemical application, and in taking English classes. other regions of the U.S. There are few training opportunities for Exten- sion agents as well as few Extension resources available to producers (23) Reaching Out to the Amish and Mennonite interested in organic production. Arkansas, Alabama, North and South Vegetable Growers in Missouri on Integrated Pest Carolina collaborated to offer trainings to improve knowledge and Management confidence regarding organic production and improve organic resources Sanjun Gu* to agriculture professionals including Extension, farmers market man- Lincoln University, Jefferson City, MO; [email protected] agers, and school teachers. In Arkansas, 28 agriculture professionals participated in a 2-day organic workshop which included sessions on James Quinn soils, nutrition, pest management, certification along, case studies and Cole County Extn. Center, Jefferson City, MO; [email protected] farm tours. Second level training will be offered to these professionals Currently, all five produce auctions in Missouri are operated by Amish to expand their organic production knowledge and experiences. Oppor- and Mennonite. These auctions provided a reliable market for Amish tunities to learn organic apple and bramble production practices have and Mennonite vegetable producers, as well as some other producers. been offered to producers through workshops and farm tours. Most Amish and Mennonite producers did not finish high school and Specified Source(s) of Funding: University of Arkansas have difficulties in understanding the integrated pest management (IPM) theories and practices. To help these people, five basic vegetable (21) Landscape Horticulture Extension IPM workshops and four advanced vegetable IPM workshops were Programming for Prison Inmates in Florida conducted in 2008 and 2009, with the funding supported by EPA region 7. More than 290 people attended the 5 workshops in 2008 and about Geoffrey C. Denny* 175 people (38 were returned attendees) showed up in 2009. Over University of Florida IFAS, Wimauma, FL; gcdenny@ufl.edu 2/3 of participants were Amish and Mennonite for both years. A vital Prison inmates are frequently an under-served extension audience. measurement consisting of same six IPM questions was used to test Inmate populations are often easier to quantify behavior change in the gain of workshop attendees. The IPM Transition Index (scales of because of the intensive monitoring by the state department of cor- 0 to 5) was employed to represent the progress by attendees. In 2008, rections. In Florida, vocational training has been shown to decrease same questions were given to all attendees pre- and post-workshops, recidivism by 14.6%. Roughly 1,600 inmates receive vocational training and 215 workshop assessments were completed. The average score each year. This offers $3.2 million in cost savings to the state, or about for the six assessment questions by all 205 responders indicated a $2,000 per inmate trained. A training program is being developed by pre-workshop IPM Transition Index score of 2.76 (which was higher UF/IFAS Extension that will lead to the certification of state inmates than the expectation). Assessments returned following the workshop as Florida Certified Landscape Technicians. This certification is one of scored 3.54, resulting in a gain of 0.78 from joining the presentations five offered by the Florida Nursery Growers and Landscape Association. at the workshops. In 2009, only those 38 returned participants were Inmates will be trained on 12 topics including: Plant ID, Plan Layout, surveyed with the same questions. The IPM Transition Index was 3.51, Tree Planting, Tree Staking & Guying, Palm Banding & Propping, which surprised us as a higher score was anticipated. However, it was Grading & Drainage, Instrument Use, Irrigation Operation & Repair, noted that the returned participants actually maintained the IPM level Pruning, Job Evaluation, Equipment Operation, and Retaining Wall of last year, indicating that the workshops were successful in promoting Construction. Training modules and curricula are being developed with the application of IPM by Amish and Mennonite vegetable growers.

1152 HORTSCIENCE, VOL. 44(4), JULY 2009 The assessment also showed the regional difference in the perception identified numerous SSR-containing sequences, developed a large set of IPM from Amish and Mennonite vegetable growers in Missouri. of EST-SSR markers, and tested these markers in a number of breed- Growers from Barnnet seemed to be more advanced in applying IPM ing and genetic applications. Of the 1,187 sequences identified out in vegetable production. of 16,994 gerbera ESTs, 31.0% contain dinucleotide repeats, 27.9% trinucleotide, 4.8% tetranucleotide, 14.0% pentanucleotide, and 19.3% Specified Source(s) of Funding: EPA Region 7’ hexanucleotide. AG (24.0%) and AAT (8.8%) motifs were the most abundant repeat types. A total of 124 SSR primer pairs were designed based on the available gerbera ESTs. When tested on the gerbera Genetics/Germplasm/Plant Breeding: cultivar ‘Jaguar Tangerine’, 108 (87.1%) of them amplified DNA frag- ments of the expected sizes. These primers were further tested on 47 Floriculture Crops gerbera cultivars and breeding lines, and 84 (77.8%) of them showed Monday, 27 July 2009 1:15–200 pm polymorphisms. Sixty-six SSR markers were further tested for cultivar identification, genetic relatedness analysis, and it was found that as few as three SSR markers could differentiate all cultivars used in the (93) Evaluating Sterility of a Late-Flowering study, 13 cultivars possess specific alleles, and cultivars tested could Ornamental Tung Oil Tree (Aleurites fordii) be grouped into several major clusters. Timothy Rinehart* USDA–ARS, Poplarville, MS; [email protected] (294) Amplification, Cloning and Characterization Ned Edwards of Resistance Gene Candidate Sequences in Gerbera USDA–ARS, Poplarville, MS; [email protected] and Caladium We recently identified an Aleurites fordii seedling with ornamental Li Gong* potential that shows late flowering, approximately 4 weeks delayed, University of Florida/IFAS, Wimauma, FL; ligong@ufl.edu and does not produce normal drupes, which are toxic and a nuisance to Zhanao Deng lawn mowers since they are large (5–8 cm) and heavy. The ornamental University of Florida /IFAS, Wimauma, FL; zdeng@ufl.edu and landscape industries could benefit from a small (4–6 meter), decidu- Improving disease resistance has become an important objective in ous landscape tree that has no known insect or disease problems, has gerbera and caladium breeding in recent years. In many cases, plant uniform growth habit, tolerates diverse soil conditions and drought, resistance traits are controlled by multiple genes and their expres- is readily propagated, and has a tropical flair with large, heart-shaped sions are affected by changes in the environment. These factors make POSTERS–Monday leaves and Catalpa-like blooms. Clusters of approximately 60 flowers it difficult to select breeding lines with high levels of true resistance. open before the leaves in early spring and have 5–7 ivory petals with The use of molecular markers has been proposed to help overcome pink to red throats. Flowers are monoecious and both male and female these difficulties. One type of the molecular markers often used to tag flowers are visible on the late-flowering selection. Staminate male flow- disease resistance (R) genes is developed from resistance gene can- ers produce visible pollen but staining and microscopy measurements didate (RGC) sequences, DNA sequences amplified with degenerate show a high percentage of large, heavily-stained pollen grains mixed primers designed from cloned R genes. The objectives of this study with unstained normal-sized pollen. Genome size comparisons using were to amplify, clone and characterize RGC sequences from powdery a flow cytometer do not suggest ploidy differences between the late- mildew-resistant gerbera and fusarium tuber rot- and pythium root rot- flowering selection and plants in our tung oil germplasm collection. resistant caladium, with the goal to develop molecular markers linked Tung oil trees are not self-sterile and flowering times for normal trees to powdery mildew resistance in gerbera and fusarium tuber rot and and the late-flowering selection overlap slightly. However, male steril- pythium root rot resistance in caladium. Twenty pairs of degenerate ity combined with late-flowering could account for the lack of drupes. PCR primers corresponding to the P-loop and GLPL motifs within the Two-way controlled crosses were made between seven bud-grafted NBS domain of plant R genes were screened, and eight pairs produced clones of the late-flowering selection and seven random plants from PCR products in gerbera and caladium. The PCR products amplified the tung oil tree germplasm collection to confirm sterility. Cold-hardi- by two pairs of primers from gerbera and by one pair of primer from ness evaluations of bud-grafted clones are underway since previous caladium were cloned and sequenced. Sixty-five gerbera sequences and literature indicates hardiness only in USDA cold-hardiness zones 8 to 18 caladium sequences were homologous to R genes. In gerbera, 58 10, which would limit the potential of this tree. RGC sequences contained continuous open reading frames (ORF); they (293) Developing EST-SSR Markers for Gerbera showed 57% to 99% of protein sequence identity and were classified into three groups. In caladium, the translated protein sequences of 15 Breeding and Genetic Analysis ORF-containing RGC sequences showed 37% to 98% sequence identity Li Gong* and were classified into three groups as well. Phylogenetic analysis University of Florida/IFAS, Wimauma, FL; ligong@ufl.edu indicates gerbera and caladium RGCs belong to the TIR NBS-LRR and Zhanao Deng the Non-TIR NBS-LRR R gene subfamily, respectively. University of Florida /IFAS, Wimauma, FL; zdeng@ufl.edu (295) Transferring SSR Markers Across Genus for SSR (simple sequence repeat) markers have become a very valuable Caladium Breeding and Genetic Analysis tool for plant breeding and genetic research and are widely used in cultivar identification, pedigree tracing, homozogosity evaluation, Li Gong* genetic relatedness analysis, genetic diversity assessment, germplasm University of Florida/IFAS, Wimauma, FL; ligong@ufl.edu differentiation and preservation, gene mapping and tagging, marker- Zhanao Deng assisted selection, etc. So far, no SSR markers have been reported for University of Florida /IFAS, Wimauma, FL; zdeng@ufl.edu gerbera, a very important cut and pot flower in the United States of Molecular markers have become a valuable tool for plant breeding and America and in the World. In this study, we mined the publicly avail- genetic research. Due to a number of their characteristics, including able gerbera expressed sequence tags (ESTs) in the Genbank database, being rich in plant genomes, hyper-variable among species/cultivars,

HORTSCIENCE, VOL. 44(4), JULY 2009 1153 co-dominant between alleles, and transportable from laboratory to (297) Chemically Induced Polyploidization in laboratory, SSR (simple sequence repeat) markers have become the Chlorophytum amaniense through Indirect Shoot choice of molecular markers to be used in many breeding and genetic applications. So far, no SSR markers have been reported (or developed) Organogenesis for caladium (Caladium ×hortulanum), a versatile pot/bedding plant Feixiong Liao and a representative of a large group of ornamental aroids including University of Florida, Apopka, FL; [email protected] aglaonema, anthurium, calla lily, dieffenbachia, spathiphyllun, etc. Juanxu Liu To identify SSR markers that can be used in caladium breeding and University of Florida, Apopka, FL; juanxu@ufl.edu genetic analysis, we have attempted to transfer SSR markers from taro Min Deng (Colocasia esculenta), another member of the Araceae and in the same University of Florida, Apopka, FL; mindeng@ufl.edu subfamily with caladium. Thirty-nine SSR-containing taro sequences Jianjun Chen* were identified in the NCBI database, and primers were designed for University of Florida, Apopka, FL; jjchen@ufl.edu 22 suitable sequences. These SSR primers and 43 pairs of previously published taro SSR marker primers were tested on several common Richard J. Henny caladium cultivars. Results showed that one pair of the newly designed University of Florida, Apopka, FL; hennyrjz@ufl.edu and four pairs of the published primers could be used in caladium, i.e. Chlorophytum amaniense, a member of the family Liliaceae, has only 7.7% of taro SSR markers are transferrable to caladium. This transfer- one cultivar known as Fire Flash. Coral-colored petioles and midribs ability across genus seems to be much lower than that in grass family contrasting with dark green leaves make it a sought after specimen. ‘Fire but higher than that in the Cucurbitaceae. Flash’ is a diploid species with 2n = 14; and a large number of seeds are produced from panicle inflorescences. After seeds set, however, the (296) Volatile Analysis of Impatiens, Impatiens dried panicle significantly reduces its overall ornamental value. Ad- walleriana, and Their Impacts on Western Flower ditionally, ’Fire Flash’ leaves are fragile and are broken easily. Since Thrips, Frankliniella occidentalis (Pergande), plant polyploidization usually reduces seed setting and increases plant Behavior sturdiness, this study was conducted to chemically induce polyploidy in ‘Fire Flash’. Seeds were sterilized in a 20% Clorox solution and Katie A. Yu* cultured in sterile water for one week on a shaker until sprouting oc- University of Illinois, Urbana-Champaign, Urbana, IL; curred. Sprouted seeds were treated with colchicine at 0.05%, 0.1%, [email protected] and 0.2%, oryzalin at 0.001%, 0.005%, and 0.01%, and trifluralin at Daniel Warnock 0.05%, 0.1%, and 0.15% for 24 h, 48 h, and 72 h, respectively, with University of Illinois, Urbana-Champaign, Urbana, IL; [email protected] shaking. The seeds were then rinsed 5 times with sterile water and Greenhouse floriculture is an important segment of the American ag- cultured on MS medium containing 4.0 mg/L TDZ and 0.2 mg/L riculture industry with bedding plants being an important commercial NAA. Seed survival rates were 98% for those treated with water but crop. As such, the horticulture industry has acknowledged the need to decreased to 38.6%, 16.5%, and 4.5% for those treated with colchicine, maintain the aesthetics and health of these crops through the reduction oryzalin, and triflualin at the maximum concentrations and durations, of insect feedings and the transmission of damaging plant viruses. With respectively. Calluses were formed from those survived seeds that failed the identification of selectable plant traits that can confer resistance to germinate. Differentiation of calluses resulted in the formation of against insect feeding, a major diminution is made in plant damage shoots. Characterization of morphologically different regenerated plants and a corresponding reduction in insecticide applications throughout using DNA flow cytometry showed that polyploidization occurred production. Impatiens (Impatiens walleriana) cultivars have been bred among those plants. Flowering characteristics and leaf robustness will and selected over many generations for flower color, flower size, plant be evaluated to determine if polyploidized ‘Fire Flash’ set fewer seeds shape and habit and previous research has identified certain strains that and if leaf sturdiness is improved once the plants mature. are endowed with resistance to western flower thrips (WFT, Frankliniella (298) Potential for Crop Improvement in occidentalis) infestation. To determine whether there exists an underlying biochemical factor to impatiens resistance to WFT beyond visual cues, Ornamental Salvia Via Interspecific Hybridization experiments were undertaken to explore the hypothesis that emitted Joseph Tychonievich* plant volatile compounds contribute to the observed resistance. In this Michigan State University, East Lansing, MI; [email protected] research, the behavioral responses of adult WFT to volatiles from potted Ryan M. Warner impatiens were investigated using a Y-olfactometer. Individual WFT Michigan State University, East Lansing, MI; [email protected] ability to differentiate between purified air and volatile compounds of whole impatiens plants was determined. Using purified air and chry- Salvia L. is a genus of over 900 species, including many horticulturally santhemums (Chrysanthemum xmorifolium, ‘Chesapeake’) as controls, important crops grown as annuals and perennials. Several interspecific the simple experimental design allowed for comparing four impatiens hybrids (e.g. S. ×superba Stapf and S. ×jamensis J. Compton) are lines varying in resistance and susceptibility. The dynamic headspace commercially important; however most of these hybrids are the result volatile components of the plants and controls were then analyzed by of hybridization in the wild or accidental hybridization in cultivation. capillary gas chromatography/ mass spectrometry (GC/MS). The results Introgressing wild germplasm in Salvia breeding programs has the discussed herein demonstrate that different breeds of impatiens have potential to introduce novel traits, but there is little information on variations in the production of volatile compounds. This variation has interspecific fertility in the genus. To evaluate crossability within the a dynamic impact on thrips behavior and response with some cultivars genus, nine salvia species were selected to represent a wide diversity of being more attractive than the purified air sample. We suggest that a native range, phylogenetic relationship, and chromosome number. All complex interplay between the visual and biochemical cues confers species were crossed with each other in every possible combination. WFT resistance to impatiens. Overall, crossability in the genus was low, but exhibited unexpected fertility between phylogenetically and geographically distant species. Specified Source(s) of Funding: UIUC Research Board Similarly, crosses between species with very different chromosome numbers showed unexpected fertility. One successful hybrid, S.

1154 HORTSCIENCE, VOL. 44(4), JULY 2009 nemorosa L. × S. transsylvanica Schur ex. Griseb., is of particular Erszebet Buta interest as S. nemorosa is a widely used floriculture crop, despite University of Agricultural Sciences & Veterinary Medicine Cluj-Napoca having small flowers. Salvia transsylvanica has much larger flowers (USAMVCluj), Cluj-Napoca; [email protected] than S. nemorosa, and may be a useful genetic source to increase S. The roses are extensively grown in Romania as commercial crop, as nemerosa floral size. A large segregating F population has been raised 2 cut flowers and also are used as landscape design. At the Research Fruit from this cross for genetic mapping of loci controlling flower size and Station Cluj (SCDP CLUJ) there are rich collections of germplasm of other traits. The F population individuals exhibited variation in flower 2 Rosa sp, collected from many countries. The University of Agricultural size extending beyond the parental values. Similarly, large variation Sciences and Veterinary Medicine Cluj-Napoca has improved in the in flowering time and leaf morphology was observed. These results recently years the ornamental collection with 9 rose cultivars obtained indicate a great potential to utilize wild Salvia species to improve and from SCDP Cluj, which can be used for student practice, research ac- to introduce novel traits into commercial genetics. tivities and will be recommended for commercial culture. Introducing Specified Source(s) of Funding: Private; USDA Floriculture and Nursery the most competitive foreign cultivars in the Rosa culture is the main Research Initiative; HATCH way of increasing the rose production (Wagner St., 2002). The new rose cultivars belong to Hybrid tea: ‘Acapella’, ‘Black Velvet’, ‘Caprice (299) Inheritance of Crop Timing and Quality Attri- de Meilland’, ‘Fruhrot’, ‘Imperatrice Farah’, ‘Mondiale’, ‘Monica’, butes in Petunia Interspecific Hybrid Populations ‘Valencia’ and ‘White Success’. These cultivars where studied in the period 2006–08 for behaviours in our Transylvanian and recorded for Ryan M. Warner* the following characteristics: blooming time and intensity, colour and Michigan State University, East Lansing, MI; [email protected] shape flowers, diameter of flower, number of petals, fragrance, plant The rate of node appearance (i.e. leaf unfolding rate) is one factor height, bloom repeatedly, resistance to diseases and cold. The decorative determining crop timing. Many greenhouse crop growers in northern value of new varieties was established in the field by judging method climates have reduced greenhouse temperature in an attempt to reduce of characteristics for each class, the maximum obtainable score being heating costs. Leaf unfolding rate is a temperature dependent process; 100 (Palacsay, 1966, Wagner, 2002). In this respects the minimum therefore lowering greenhouse temperature decreases the rate of devel- percentage for a valuable varieties is 70 points, which is the lower opment, increasing production time. Developing cultivars with higher limit for a good and very good behavior. The observations were made rates of development at lower temperatures is one long-term strategy for 10 plants from each variety. The cultivars studied have a rich range for improving energy efficiency of greenhouse crop production. Initial of colours (white, red dark, salmon, apricot, bengal pink, striped or experiments indicated that wild relative species of the modern cultivated spotted, etc.) are vigorous with great number of petals/flower, repeat POSTERS–Monday petunia (Petunia ×hybrida Vilm.) have higher leaf unfolding rates flowering, excellent disease in garden, a bushy well-branched habit. than modern cultivars and may therefore be useful genetic sources to Fragrances in roses of all types have always been important to us and develop cultivars with decreased production time, particularly at cool remarks: Acapella, Black Velvet, Caprice de Meilland, and Valencia.

(< 20 °C) temperatures. Three interspecific F2 populations, P. axillaris The most representative Rose cultivars can be used for landscape (Lam.) Britton et al. × P. hybrida ‘Mitchell’, P. axillaris × P. exserta design in borders, gardens, or are grown as cut flowers for bouquets Stehmann and P. integrifolia (Hook.) Schinz & Thell. × P. axillaris or arrangements. Organizing some green spaces to be more and more were phenotyped for crop timing and quality parameters, including leaf attractive requires a well knowledge of the morpho-biological and number below first flower, time to flower, leaf unfolding rate, branch cultural characteristics of the rose cultivars and the choice of the most number, flower bud number, and flower size. All three populations ex- suitable combinations. hibited transgressive segregation for leaf unfolding rate. Leaf unfolding rate was not correlated with time to flower in any of the populations, (301) Evaluation of Vinca Cultivars for the suggesting these traits could be selecting for independently to develop Landscape or as Potted Plants in Guam genotypes with high leaf unfolding rate and reduced time to flower. James McConnell* Leaf number below the first flower was positively correlated with leaf University of Guam, Mangilao; [email protected] unfolding rate in all populations except P. integrifolia × P. axillaris. Time to flower was strongly positively correlated with flower bud number in Forty-nine vinca (Catharanthus roseus) cultivars were evaluated for the P. axillaris × P. hybrida ‘Mitchell’ population (P < 0.001), weakly days to flower, flower diameter, flower color, plant dimensions, general correlated in the P. integrifolia × P. axillaris population (P = 0.042), tolerance to disease and appearance during the drier months in Guam. but not significantly correlated in P. axillaris × P. exserta individuals. While vinca can be a perennial in Guam’s growing conditions, the Together, these results indicate that wild germplasm could be useful majority of cultivars succumb to target leaf spot (Corynespora cas- for developing petunia cultivars with accelerated time to flower, but silcola) once rainfall increases. Mediterranean cultivars were found to reductions in crop quality parameters may need to be overcome. be highly susceptible to target leaf spot. Plants were grown in soil in raised beds and in pots on raised beds. In general, the cultivars survived Specified Source(s) of Funding: Private; HATCH; USDA Floriculture longer in pots than in ground beds. and Nursery Research Initiative Specified Source(s) of Funding: USDA Hatch (300) Introduction of New Roses Cultivars Into Ornamental Collection and Their Behavior in Genetics/Germplasm/Plant Breeding: Transylvania Conditions Vegetable Crops and Cross-Commodity 1 Maria Cantor* Monday, 27 July 1:15–2:00 pm University of Agricultural Sciences & Veterinary Medicine Cluj-Napoca (USAMV Cluj), Cluj-Napoca; [email protected] (324) Rate of Natural Outcrossing in Watermelon as Corina Catana University of Agricultural Sciences & Veterinary Medicine Cluj-Napoca Affected by In-row Spacing (USAMVCluj), Cluj-Napoca; [email protected] Rakesh Kumar* North Carolina State University, Raleigh, NC; [email protected]

HORTSCIENCE, VOL. 44(4), JULY 2009 1155 Todd Wehner fungicide Sporatec and the insecticide Ecotec, an organic system based NC State University, Raleigh, NC; [email protected] on the fungicide Serenade and the insecticide Neem, and a control. In this study, ‘Mountain Magic’, ‘Stupice’, and ‘Red Brandywine’ were Watermelon (Citrullus lanatus) is a cross-pollinated crop. Estimation rated the best in consumer taste tests and also had the highest organic of natural outcrossing rate is important to plant breeders to determine acid content. This indicates that organic acid analysis may be a fair the minimum isolation distance required for seed increase and to de- criterion for screening genotypes for flavor. Interestingly, fruit from sign a suitable breeding strategy for crop improvement. There is little the two organic systems had the highest concentration of organic inbreeding depression in watermelon, indicating a lack of dominance acids, which was positively correlated with flavor. This indicated variance, and possibly a high rate of self-pollination. Hence, the ob- that tomatoes grown under organic conditions may have better flavor jective of this study was to determine the natural outcrossing rate in than those grown under a conventional system. Total acid content watermelon to determine the distance that pollen can be transferred and sugars were negatively correlated indicating that organic acid is by honeybee (Apis mellifera). The experiment was a split plot in a converted into sugars when fruits are ripe. Across all varieties, there randomized complete-block design with 7 replications. Whole plots was no difference in total marketable yields among the conventional or were 2 locations (Kinston and Clinton, NC), sub-plots were the 8 in- organic production systems, but they were all higher than the control. row spacing treatments. Spacing treatments were 0.610, 1.219, 1.829, Across all production systems, ‘Stupice’, ‘Mr. Stripey’, and ‘Mountain 2.438, 3.048, 3.658, 4.267, and 4.877 m. Sub-sub plots were 2 cultivars Magic’ had higher marketable yields compared to ‘Red Brandywine’ (‘Allsweet’ and ‘Mickylee’). The cultivar ‘Moon and Stars’ was used and ‘NC 118L’. as a pollenizer. ‘Moon and Stars’ has bright yellow spots on leaves, fruit and cotyledon due to the Sp gene that is dominant to uniform Specified Source(s) of Funding: Department color. Analysis of variance showed significant differences in natural outcrossing rate due to in-row spacing. Natural outcrossing rate was (326) PA-559: A New, Root-Knot Nematode low (< 1.8%) where a wide in-row spacing (> 4.267 m) was used. At Resistant, Red-fruited, Habanero-type Pepper any spacing greater than 4.267 m, natural outcrossing rate was low. Richard Fery* On the other hand, close in-row spacing had a significantly higher rate U.S. Dept. of Agriculture, ARS, Charleston, SC; [email protected]. of natural outcrossing. A high rate of self-pollination can be achieved gov in watermelon plants trained in a tight spiral and spaced more than Judith A. Thies 4.267 m (14 ft.) apart. U.S. Dept. of Agriculture, ARS, Charleston, SC; [email protected]. Specified Source(s) of Funding: NC State Univ gov (325) Tomato Flavor Affected by Variety and Efforts to develop a root-knot nematode resistant, red-fruited, Habanero- type pepper (Capsicum chinense Jacq.) were completed with the official Production System release of PA-559 on September 18, 2008. The new breeding line is Dilip R. Panthee* the product of a backcross/pedigree breeding procedure to incorporate North Carolina State University, Mills River, NC; dilip_panthee@ncsu. a dominant root-knot nematode resistance gene from the Scotch Bon- edu net-type accession PA-426 into a red-fruited Habanero-type pepper. Jeanine M. Davis PA-559 was derived from a single F3(BC4F3 × BC4F3) plant grown in North Carolina State University, Mills River, NC; jeanine_davis@ncsu. 2005. Both of the parental lines used in the last cross are sister lines of edu the orange-fruited, root-knot nematode resistant cultivar TigerPaw-NR Luis Perez-Albela that was released by the USDA in 2006. PA-559 is homozygous for a University of Tennessee, Knoxville, TN; [email protected] dominant gene conditioning a high level of resistance to the southern Carl Sams root-knot nematode [Meloidogyne incognita (Chitwood) Kofoid and The University of Tennessee, Knoxville, TN; [email protected] White], the peanut root-knot nematode [M. arenaria (Neal) Chitwood], and the tropical root-knot nematode [M. javanica (Treub) Chitwood]. Heirloom tomatoes are in high demand because consumers expect PA-559 has a compact plant habit and produces lantern-shaped, red- them to have excellent flavor and they are available in many attractive colored fruit. Observations of field plantings conducted at Charleston, colors and sizes. There is also a growing demand for organic heirloom SC, indicate that the fruit and yield characteristics of PA-559 are tomatoes. Although this is a good opportunity for farmers, there are comparable to those of currently available Habanero-type cultivars. A some problems associated with growing heirloom tomatoes, particularly typical fruit weighs 7.8–8.3 g, is 2.3-2.7 cm wide × 4.2-4.6 cm long, organic ones. These include disease susceptibility, lack of research and is extremely pungent (256,433 Scoville heat units). PA-559 is on effective organic production systems, and limited information on recommended for use as a parental line by pepper breeders interested how varieties perform and are accepted by consumers. In order to ad- in developing root-knot nematode resistant cultivars of Habanero-type dress these problems, NC State University started a research program peppers. PA-559 is a well-adapted, Habanero-type pepper; it is potentially on heirloom tomatoes in 2005. Over the past four years, that project useful in commercial production without further development. has shown that an organic production system can be as effective and productive as a conventional one. Furthermore, some of the heirloom (327) Assembling Germplasm Collections of Nuttall’s varieties and heirloom-type hybrids are very disease resistant and well Povertyweed [Monolepis nuttalliana (Schult.) suited for organic production in the Southeast United States. To under- Greene] and Other Spinach (Spinacia oleracea L.) stand the fruit biochemistry of different heirloom and heirloom-type hybrid tomato varieties in 2008 we compared flavor rated by sensory Allies methods and fruit quality components such as organic acids, sugars David M. Brenner* and volatiles of tomato varieties grown under different production Plant Introduction Station, Ames, IA; [email protected] systems. The varieties were the heirloom-type hybrids, NC 118L, NC Grace Kostel 161L, and Mountain Magic, and the heirloom varieties Mr. Stripey, Black Hills State University, Spearfish, SD; [email protected] Red Brandywine, and Stupice. They were grown under the following Mark P. Widrlechner production systems—conventional, an organic system based on the USDA–ARS Plant Introduction Station, Ames, IA; mark.

1156 HORTSCIENCE, VOL. 44(4), JULY 2009 [email protected] (329) Evaluation of Heterosis and Combining Ability Candice A. Gardner for Important Characters in Muskmelon USDA–ARS Plant Introduction Station, Ames, IA; candice.gardner@ars. usda.gov Saroj Rolania Rajasthan Agricultural University, ARS, Durgapura, Jaipur; The USDA–ARS North Central Regional Plant Introduction Station [email protected] in Ames, Iowa maintains an extensive working collection of Spinacia Manphool Fageria* germplasm, both of cultivated and wild types, as part of the US Na- University of New Brunswick, Fredericton, NB; [email protected] tional Plant Germplasm System. We seek to expand these collections by acquiring samples of allied genera, including Micromonolepis, Muskmelon (Cucumis melo L.) is an important dessert fruit, cultivated Monolepis, and Suckleya. Assembling this germplasm may facilitate during the arid summer months in north Indian plains. Being dessert rigorous studies of horticulturally valuable traits and clarify their true fruit, quality parameters, especially TSS, flesh thickness, texture, colour phylogenetic relationships. The povertyweeds (Monolepis) include and higher sugar content are the important one. Round fruits with orange five species native to the New World and Asia. Nuttall’s povertyweed thick flesh and tough/netted rind suitable for long distance transporta- is native from Alaska south to Mexico, but is found primarily in the tion are preferred in the market. Earliness is of greater importance, as Intermountain West and High Plains, where it commonly grows in market prices for such a crop are exorbitant and they can ultimately seasonally moist swales on alkali, clay soils. This annual species is lead to higher net returns to the growers. However, growers of north known to have edible leaves, seeds, and roots. Its foliage resembles India are still not happy with the existing varieties of muskmelon that of spinach, especially when young, and can be prepared as cooked especially due to their low yield potential, poor keeping quality, and greens. It is considered to be a minor weed in agriculture, germinating lower sweetness. Therefore the objective of this study was to develop in spring and developing quickly during cool weather. In 2008, we hybrids of muskmelon combining desirable characteristics. Eight ge- acquired Nuttall’s povertyweed seeds from wild populations in South netically diverse parents viz., Kesar, exotic collections (EC-2, EC-3, Dakota and Nebraska and are now regenerating them to produce suf- EC-4, EC-5), and indigenous collections (GP-210, GP-211, GP-141) ficiently large samples to facilitate their conservation and distribution were crossed in a diallel fashion excluding reciprocals. The resulting 28 for research. This poster will describe the newly collected germplasm, F1’s were evaluated with their parents in completely randomized block their germination and regeneration, and the species’ ethnographic design with three replications under open field conditions. The analysis use history. of variance revealed presence of considerable genetic variability for all the characters studied. A highest positive and significant heterosis for (328) Productivity and Quality of Nine Cabbage fruit yield over existing commercial hybrid Abhijeet (standard hetero- POSTERS–Monday Varieties in Northeast Sonora, Mexico sis) was exhibited by the cross EC-3 × GP-211 (26.67%) followed by the cross EC-5 × GP-211 (25.00%), EC-3 × EC-4 (23.33%) and EC-3 Rubén Macias Duarte × EC-5 (18.33%). Estimates of gca and sca were found to be highly INIFAP, Caborca Sonora 83600; [email protected] significant. Parent GP-210 and GP-211 were best general combiners Raul Grijalva-Contreras* for vine length, number of fruits per hill and TSS. Parent GP-211 and INIFAP, Caborca Sonora 83600; [email protected] GP-141 were best for days to first fruit harvest while EC-5 and EC-3 Fabián Robles Contreras for fruit weight. Parents EC-2 and Kesar were best for small size of INIFAP, Caborca Sonora 83600; [email protected] seed cavity, higher flesh thickness, and rind thickness and resistance to Manuel Valenzuela Ruiz fruit fly. On the basis of overall performance, the two best crosses were INIFAP, Caborca Sonora 83600; [email protected] Kesar × EC-2 and EC-3 × GP-211. Kesar × EC-2 was superior in fruit Fidel Nuñez Ramirez weight, yield, size of seed cavity, flesh and rind thickness, shelf life ICA–UABC, Caborca, Sonora; [email protected] and resistance to fruit fly. EC-3 × GP-211 took lesser days to harvest first fruit and recorded higher fruit weight, yield, rind thickness and In the north of Sonora, Mexico, it is possible to obtain high yields had least incidence of fruit fly. and quality in cabbage production in the cycles of spring, summer and autum-winter. However, are needed seed varieties adapts the Specified Source(s) of Funding: Personal funds temperature conditions of these seasons that have a high potential for quality and yield. The objective of this experiment was to evalu- (330) Inheritance of Papaya Ringspot Virus ate nine varieties of cabbage. The evaluation was carried out in the Resistance in Temperate and Tropical Genotypes of INIFAP-CIRNO Experimental Stación (Magdalena of Kino, Sonora) Pumpkin in winter 2004 under field conditions. The evaluate varieties were: Robert McPhail-Medina* Discovery, Charnant, Atlantis, Izalco, Blue Pak (Harris Moran), Red University of Puerto Rico, Mayaguez, PR; [email protected] Sun, Blue Dinasty, Blue Pak (Ferri Morse), and Tlixco. The date Linda Wessel-Beaver seedling trasplant establishment was on Febraury 17, 2004. We used University of Puerto Rico, Mayaguez, PR; [email protected] a plant density of 57,000 plants/ha in furrows with two rows using drip irrigation system. In this trials, we used a completely randomised José Carlos V. Rodrigues desing with four replications. The measured variables were yield, head University of Puerto Rico, Río Piedras, PR; [email protected] weight and head diameter. The harvest period was 9 to 27 June. The Cucurbita moschata Duchesne (butternut squash, tropical pumpkin) results indicated that the highest yield were obtained from:the varieties: is an important vegetable crop in tropical and subtropical regions Discovery, Charmant, Atlantis, and Izalco with 100.7, 97.5, 87.7, and worldwide. The disease caused by Papaya ringspot virus (PRSV) -1 85.7 t·ha , respectively. The highest head weight were obtained from has a negative impact on the yield of this and other cucurbit crops. In Discovery, Charmant, Izalco and Atlantis with 1.7, 1.5, 1.5, and 1.4 Puerto Rico, PRSV is one of the two most common viruses affecting kg, while what the highest head diameter corresponded to Discovery, tropical pumpkin. One of the goals of our breeding program at the Atlantis, Blue Pack (Harris Moran), and Red Sun with 16.5, 15.5, University of Puerto Rico is to incorporate resistance to PRSV into 15.0, and 15.0 cm, respectively. local cultivars. C. moschata cv. Nigerian Local (NL) has been used Specified Source(s) of Funding: INIFAP as a source of resistance to various cucurbit viruses, including PRSV.

HORTSCIENCE, VOL. 44(4), JULY 2009 1157 Inheritance of PRSV resistance was previously reported to be a single sprouts had the highest concentrations of chlorophyll and carotenoid recessive gene based on a study in the population NL × ‘Waltham’ (a pigments. Broccosprouts had the lowest concentrations of violaxanthin, temperate butternut type of C. moschata). Nevertheless, our experience antheraxanthin, zeaxanthin, β-carotene, and chlorophyll pigments. when attempting to backcross NL resistance into tropical genotypes of Previous research in our group has demonstrated that mature vegetables C. moschata suggests that the inheritance might be more complex. The of the Brassicaceae have significant genetic variation for leaf tissue objective of this study was to confirm the inheritance of resistance PRSV pigment concentrations. Results from this study have shown sprout in additional populations. The F1, F2, and BC1 generations derived from tissue carotenoid concentrations can be high; however, carotenoid the cross of NL x various susceptible C. moschata genotypes (‘Waltham’ pigments remain at consistent levels in sprout tissues among different and tropical genotypes ‘Soler’, ‘Taina Dorada’, ‘Verde Luz’) were used Brassicaceae vegetables. to test the inheritance of PRSV resistance. The cotyledons of 9 to 12 Specified Source(s) of Funding: TN Agricultural Experiment Station day old plants were mechanically inoculated with a local, molecularly characterized PRSV isolate. Symptoms were evaluated from 10 to 40 (332) Our Sleeping Asset: A Strategic Approach to days post-inoculation. The virus was monitored by ELISA. Inoculated Getting Value from Plant Breeding Reports plants of NL remained completely free of symptoms. When only F2 plants completely free of symptoms were classified as resistant, we did Ann Marie Thro* not observe a 3 : 1 (susceptible : resistant) ratio as would be expected USDA CSREES, Washington, DC; [email protected] with a single recessive gene for resistance. When plants with very mild Each report from a public plant breeding project is an opportunity for symptoms were included in the “resistant” category, the segregation public relations and public education about the value of plant breeding

fit a 3 : 1 ratio in each of the F2 populations. Many of the resistant F2 in general, and your program in particular. Reports may go far: they individuals showed some degree of very mild symptoms, rather than reach director’s offices, state houses, and farm groups; through USDA, being symptom-free. When these F2 individuals classified as resistant some go as far as Congress and the White House. There is much more were planted in the field, many of these plants developed mild to severe that can be done, with little or no additional effort, to make existing PRSV symptoms. Very few plants remained symptom-free. This study reports tell more and work harder for plant breeding, without adding demonstrates the importance of progeny testing of resistant individuals to the reporting burden. The potential reach of every report makes it when selecting for PRSV resistance. worth-while to take a strategic look at the reporting we already do. This presentation will consider ways to increase the impact of the reports Specified Source(s) of Funding: USDA-CSREES-Hatch; USDA-CS- you already write. It will also describe some common omissions or REES-TSTAR; USDA-CSREES-HSI misunderstandings that unnecessarily reduce the value of reports even (331) Carotenoid Concentrations in Brassicaceae from programs that are, in reality, strong and successful. Fortunately, Sprouts Do Not Differ Among Genotypes these errors are often readily corrected. Mature breeding programs have a history of impact to draw on to add value to their reporting. For a new Kristin Abney* plant breeding program, the challenge is greater. Would it be construc- Knoxvlle, TN; [email protected] tive for plant breeding, as a discipline, to develop excellence criteria Dean Kopsell that new plant breeding programs can use for planning and reporting? The University of Tennessee, Knoxville, TN; [email protected] What would such criteria be? How would they be established? Finally, Vegetable crops marketed as sprouts are becoming increasing popular the Plant Breeding Coordinating Committee exists to serve the need with health conscious consumers in the U.S. Research conducted by for sustained leadership on national strategic issues relating to plant scientists at John Hopkins University School of Medicine lead to the breeding, as issues arise, evolve, and change over time. Such an entity development of broccoli (Brassica oleracea var. italic) sprouts (Brocco- is relevant in a democratic society where public decisions are reached Sprouts®) marketed based on their concentrations of the anticarcinogenic through a constant process of dialogue and give and take. glucosinolate sulforaphane. Vegetables from the Brassicaceae family Specified Source(s) of Funding: CSREES USDA are well known for their pungent flavors and high concentrations of antioxidant secondary metabolites. Sprout blends of broccoli, clover (Trifolium L. species), mustard (B. juncea L.), radish (Raphanus sativus Horticultural Crops Culture and Management: L.), and alfalfa (Medicago sativa L.) are now available. What remains Landscape and Turf uncertain are the concentrations of other antioxidant secondary me- Monday, 27 July 2009 1:15–200 pm tabolites provided by Brassicaceae sprouts. The goal of our project was to indentify and characterize carotenoid compounds present in sprout tissues of several Brassicaceae species and compare their values with (202) Soil Moisture-Monitoring Devices in Field BroccoSprouts. We grew and evaluated sprouts of: Brassica oleracea Experiments var. fimbriata ‘Dwarf Siberian Improved Kale’; broccoli (unknown Luci Fisher* cultivar); ‘Scarlet Globe’ radish; brown mustard (unknown cultivar); University of Florida, Fort Lauderdale, FL; lefisher@ufl.edu ‘Florida broadleaf’ mustard; and B. rapa var. rosularis spinach mustard (unknown cultivar). Seeds of each species were sprouted on paper towels Kimberly Moore in propagation domes in a RCB design in a glasshouse in Knoxville, University of Florida, Fort Lauderdale, FL; klock@ufl.edu TN for 16 days before harvest. BroccoSprouts were purchased locally. The Fieldscout TDR 100 Soil Moisture Probe was compared to the Pigments present in the sprouts were extracted and measured for us- Watermark Soil Moisture Meter that uses sensors placed six inches ing HPLC methodology. Across all genotypes, sprouts were found to below the soil surface. We compared the cost effectiveness, portability, have high concentrations of nutritionally important carotenoids (5.0, ease of use, and accuracy. We used both devices for monthly evaluations 0.6, and 2.3 mg/100 g fresh weight for lutein, zeaxanthin, and β-caro- on Hibiscus plants being watered either every two days or every four tene, respectively). However, results showed no differences among days in a field experiment. Data was collected when the plants were genotypes for violaxanthin, neoxanthin, lutein, zeaxanthin, β-carotene, both stressed (prior to an irrigation event) and unstressed (the day of an chlorophyll a, or chlorophyll b pigments. Only antheraxanthin dem- irrigation event). Based on data collected, there was no significant differ- onstrated significant differenced among genotypes. In general, radish

1158 HORTSCIENCE, VOL. 44(4), JULY 2009 ence on the portability or the accuracy of both devices. The Fieldscout Lisa Rew TDR 100 was easier to use due to the fact that it was not necessary to Montana State University, Bozeman, MT; [email protected] find the sensors to hook up to a meter as was done with the Watermark. Sod mixes for the California ecoregions of Pacific Forest, Sierran For- The Fieldscout cost was $645.00 for the Probe and $48.00 for the rod, est, and Intermountain Sagebrush were grown at two different planting while the Watermark Meter cost was $278.00 for the meter and $32.00 densities (500 and 1000 pure live seed per square foot) in 4’ x 5’ plots. for each sensor. For this experiment thirty-six sensors were used at an High density sod, produced over eight months had significantly higher original cost of $1152.00. However, in the course of the experiment sod strength than the lower density sown sod. At harvest, both densi- some had to be replaced adding to an additional cost. ties of sod were transported onto prepared soil beds with and without (203) Impact of Four Irrigation Treatments on Seven reinforcement mats. Known quantities of weed seeds were mixed in the top 2 centimeters of the soil beds. All sod rapidly established on the Shrub Species growing medium, regardless of density or reinforcement mat. Both the Ronda Koski* mat and high initial planting density sod suppressed weeds. The initial Colorado State University, Fort Collins, CO; [email protected] planting density and presence or absence of reinforcement materials James Klett affected the resulting species composition. All species transferred suc- Colorado State University, Fort Collins, CO; [email protected] cessfully, but Bromus and Festuca predominated with <5% comprising Jason Smith the remaining species in the mixes. The higher sowing densities proved Colorado State University, Fort Collins, CO; [email protected] more successful, suggesting that they are necessary for transport of na- tive grass species mixes sod. Reinforcement mats aided in sod transport In 2005, Colorado State University initiated a study to determine the coherence and did not hinder establishment of the sod. impact of irrigation treatments on several common shrub species. Ir- rigation treatments of 100%, 50%, 25%, and 0% were based on the Specified Source(s) of Funding: California Department of Transporta- evapotranspiration of Kentucky blue grass. Four species considered tion “low water use” and three species considered “very low water use” were chosen for the study. Low water use species included serviceberry (205) Water-Use of Eriogonum corymbosum in An (Amelanchier alnifolia), blue mist spirea (Caryopteris incana), Meyer Irrigated Field Study lilac (Syringa meyeri ), and common lilac (Syringa vulgaris ). Very Graham C. Hunter* low water use species included fernbush (Chamaebatiaria millefolium Utah State University, Logan, UT; [email protected] ), Russian sage (Perovskia atriplicifolia), and three leaf sumac (Rhus

Heidi Kratsch POSTERS–Monday trilobata). At the end of the 2007 growing season, none of the species Utah State University, Logan, UT; [email protected] showed signs of physiological stress associated with insufficient soil Roger Kjelgren moisture. In 2008, irrigation treatments were applied over a 15-week Utah State University, Logan, UT; [email protected] period; during this time 22.0, 11.0, 5.5, and 0.0 gallons of water were applied weekly to each shrub in the 100%, 50%, 25%, and 0% subplots, David Hole respectively. Predawn leaf water potentials indicated that serviceberry Utah State University, Logan, UT; [email protected] in the 100% subplot were less water stressed than their counterparts in Leila Shultz the 50%, 25%, and 0% subplots; irrigation treatments had no impact Utah State University, Logan, UT; [email protected] on the water relations in three leaf sumac; and common lilac in the Eriogonum corymbosum is a highly diverse species native to the In- 100%, 50%, and 25% subplots were less stressed than their counter- termountain West with aesthetic and drought tolerance characteristics parts in the 0% subplot. Irrigation treatments had no effect on size of that make it desirable for low water or conventional urban landscapes. serviceberry, blue mist spirea, or common lilac; and treatments had no Since little is known about how its performance in irrigated settings, effect on visual appeal of serviceberry, Meyer lilac, or common lilac. we investigated its range of water tolerance to frequent and no irriga- Visual appeal of blue mist spirea decreased as irrigation increased. tion in a landscape setting. Out of 15 E. corymbosum accessions two Size of three leaf sumac increased as irrigation increased. Meyer lilac were selected. These two were collected at notably different elevations shrubs in the 100% subplot were larger than their counterparts in the and display dissimilar leaf morphologies. The two E. corymbosum 0% subplot. By the end of the 2008 growing season, none of the species accessions, along with Cornus sericea ‘Kelseyi’ as a drought-intoler- displayed signs of physiological stress associated with insufficient soil ant reference, were irrigated every three days, every three weeks, or moisture. Leaves of serviceberry in the 100% subplot were larger than no supplemental water added. Stomatal conductance and pre-dawn those in the 50%, 25%, and 0% subplots; leaves of three leaf sumac water potential were measured weekly. Prior anecdotal observations and common lilac in the 100%, 50%, and 25% subplots were larger suggested that E. corymbosum is damaged or dies in very wet soils, than their counterparts in the 0% subplots; and irrigation treatments but both accessions irrigated every three days showed no injury. In late had no impact on the leaves of blue mist spirea. Findings from this August 2008, non-irrigated, higher-elevation accession plants averaged study indicate that although some irrigation may be necessary for the substantially higher stomatal conductance (524 mmol·m-2·s-1) than long-term health of established common lilac, established serviceberry, the non-irrigated lower-elevation accession plants (344 mmol·m-2·s-1). blue mist spirea, three leaf sumac, and Meyer lilac can survive with Non-irrigated C. sericea ‘Kelseyi’ appeared to be water stressed, as it little or no irrigation. averaged 18 mmol m-2·s-1 over the same period. However, late August Specified Source(s) of Funding: State commodity groups and founda- water potential measurements for both the E. corymbosum accessions tions and C. sericea ‘Kelseyi’ were not significantly different. Plants of C. sericea ‘Kelseyi’ grew well under frequent irrigation, but non-irrigated (204) Native Grass Sod Suitability for plants of this species ceased transpiring under initial soil drying early Transportation and Competition with Resident in the season and showed considerable margin burn by season end. Weeds The two E. corymbosum accessions showed no visible signs of water stress, but differed considerably morphologically. The high elevation Tracy Dougher* accession had much smaller blue-green leaves, in compared to the Montana State University, Bozeman, MT; [email protected] larger yellow-green leaves of the low elevation accession. These data

HORTSCIENCE, VOL. 44(4), JULY 2009 1159 suggest that morphological differences may be linked to physiological potting mix. Tecoma seedlings were planted on 5 June in the ground differences observed in E. corymbosum and both will be considered or in bags placed on top of the ground, and data were collected on 22 in selecting the best drought-tolerant accession for further cultivar July and 13 September. In July, Tecoma plants growing in the topsoil or development. potting mix bag treatments fared significantly better than those growing in the ground, in all parameters measured. Plants grown in the bags Specified Source(s) of Funding: University credit card with potting mix were significantly taller and wider, and earned better (206) Validating Nitrogen Fertilization visual quality ratings than those grown in bags of topsoil, but potting mix vs. topsoil made no significant difference in number of flowers. Recommendations for Florida Landscape Plants— Plants grown in the ground had only barely initiated flowering by 22 Cool Season Annuals July, while those grown in the bags averaged 9 to 10 flowers per plant. Gitta Shurberg* Data were not taken in August because plants were suffering from University of Florida IFAS, Wimauma, FL; sgitta@ufl.edu extremely wet conditions—more than 13 inches of rain fell in less than Geoffrey C. Denny one week in early August. Forty percent of the plants in the saturated University of Florida IFAS, Wimauma, FL; gcdenny@ufl.edu ground died, whereas no plants in bags died. By September, plants in bags of potting mix were more than twice as tall and three times as Amy L. Shober wide as the surviving plants grown in the ground, and were taller and University of Florida IFAS, Wimauma, FL; alshober@ufl.edu wider than plants growing in bags containing topsoil. Tecoma growing The basis for current fertilizer recommendations for ornamental plants in bags of potting mix maintained the highest visual quality ratings of the in Florida is unclear and limited and focuses on the needs of trees and three treatments. Both bag treatments also produced plants with larger shrubs. Trees and shrubs may have different nutritional requirements leaves than in-ground plants. Bag-grown plants continued flowering than do perennials, annuals, vines and groundcovers. Therefore, research in September, while ground-grown plants were not flowering. Overall, needs to be done to validate the current fertilizer. Knowledge of spe- the bags with the potting mix produced the largest, best quality plants, cific nutrient requirements will allow plants to be zoned based on their and they tended to have the most flowers. fertilizer requirements. Fertilizer zoning will result in more efficient fertilizer application thus reducing nutrient losses to the environment. Specified Source(s) of Funding: Missouri State University Plants were selected based on anecdotal evidence of high, moderate, (208) Optimizing Bag Material and Potting Mix and low fertilization needs for evaluation across a range of Nitrogen fertilization regimes. The plants were fertilized at five different N rates Components for ‘Gardening in a Bag’ based on the FYN and FL Green Industries BMP manual recommenda- Clydette M. Alsup* tions for landscape fertilization: 0.0 g N·m-2·yr-1, 9.8 g N·m-2·yr-1, 19.6 Missouri State University, Springfield, MO; clydettealsup@missouristate. g N·m-2·yr-1, 29.4 g N·m-2·yr-1, and 58.8 g N·m-2·yr-1 (2, 4, 6, and 12 edu lbs N·1000ft-2·yr-1). Nitrogen fertilization responses were determined Pamela B. Trewatha for the following cool season bedding plants: Antirrhinum ‘Montego Missouri State University, Springfield, MO; PBTrewatha@missouristate. Yellow’, Dianthus ‘Telstar Crimson’, and Viola ‘Delta Pure Violet’. edu Each of the five treatment beds were replicated three times. Every bed Gardening in a bag has been proven a viable method to easily create contained three replication groups of each species. Data collected was: garden beds for such plants as vinca (Catharanthus roseus). However, plant growth measurements, aesthetic quality ratings (1-5), chlorophyll ideal bag material and components of the potting mix inside the bags measurements (using a SPAD meter to measure chlorophyll content), have not been determined. This experiment attempts to identify the and shoot dry mass. Plant measurements and fertilizer applications oc- type of bag and potting mix components that result in best growth and curred in six-week intervals. Plots were 10 feet by 40 feet raised beds performance of vinca grown in bags in the landscape. Vinca ‘Pacifica filled with soil with little nutrient content. Drip Irrigation was used. XP White’ plants were planted on 3 June into plastic or paper bags No mulch was added to beds in order to minimize outside nitrogen filled with 3/4ths cubic foot of topsoil, potting mix, topsoil + mush- contributions. Results indicate that N requirements differ among species room compost, or potting mix + mushroom compost. Vinca were also and were within the range recommended by Green Industries BMPs planted in the ground. Each bag or ground treatment contained three and FYN. The N rates for Antirrhinum, Dianthus, and Viola suggested plants. The research plots were covered with about 1 inch of mulch in this study were determined for optimal growth and quality and are around the plants and enough mulch around and between bags to hide more specific than the existing recommendations. the bags. Data collections occurred on 20 July and 20 September. No (207) Tecoma Grown in Bags Outperform Plants data were taken in August because plants and the research plot were stressed by 13 inches of rain that fell in less than one week in early Grown in the Ground August. In July, vinca in the ground were smaller and had fewer flowers Clydette M. Alsup* than plants in all other growing regimes, except for plants growing in Missouri State University, Springfield, MO; clydettealsup@missouristate. topsoil in plastic bags. Plants growing in treatments containing potting edu mix, whether in plastic or paper bags, tended to be taller and wider, had Pamela B. Trewatha more flowers, and earned a higher visual rating than plants growing in Missouri State University, Springfield, MO; PBTrewatha@missouristate. treatments containing topsoil. Bag treatment had no effect on flower edu size. In September, vinca growing in the ground were still smaller and Ornamental plants seldom thrive in poor soil conditions, yet in most less floriferous, and had the lowest visual quality among plants in all landscapes the soil must be tilled and amended or mounded into raised growing regimes. Vinca growing in treatments containing potting mix beds before a garden can be established. Proper soil preparation can be tended to be taller than plants in treatments containing topsoil, but plant laborious, expensive and time-consuming, which may discourage many width and flower and leaf diameter were generally not significantly dif- homeowners from establishing ornamental gardens. Gardening in a bag ferent among the bag treatments. Plants growing in bags made of paper allows gardeners to create instant raised beds. This study evaluated had more flowers than plants growing in plastic bags with the exception the performance of Tecoma stans ‘Mayan Gold’ grown in the ground of plants growing in plastic bags containing topsoil + compost. The or grown in paper bags containing 3/4ths of a cubic foot of topsoil or highest-quality plants, based on visual ratings, were those grown in

1160 HORTSCIENCE, VOL. 44(4), JULY 2009 topsoil in paper bags, although several other bag treatments produced This study investigated the efficacy of common tree seedling establish- plants that were statistically similar in appearance. ment methods at two Seattle parks in the context of Seattle urban forest restoration. Drip irrigation, irrigation supplement (DriWater gel packs), Specified Source(s) of Funding: Missouri State University and woodchip mulch were tested alone and in combination. Three (209) Rudy Haag Burning Bush (Euonymus alatus) native conifers were tested in the study: Thuja plicata, Abies grandis, Tsuga heterophylla. Stem water potential, soil moisture status, and site as a Non-Invasive Alternative to Current Burning analysis suggest that: 1) seedling mortality was highly site specific; 2) Bush Cultivars summer drought was responsible for seedling mortality in Seattle parks; C.H. Finneseth* and 3) woodchip mulch could be an economic way to alleviate water University of Kentucky, Lexington, KY; [email protected] stress. Our findings also emphasize the need for site and species-specific Robert Geneve methods for conifer establishment in Seattle parks. University of Kentucky, Lexington, KY; [email protected] Specified Source(s) of Funding: Cascade Land Conservancy, Seattle Winston Dunwell Parks and Recreation, Seattle Public Utilities University of KY Res & Ed Center, Princeton, KY; [email protected] (211) Flowering Ornamentals and Their Burning bush (Euonymus alatus) is a popular ornamental shrub and an easily grown, profitable nursery crop. Many states, however, have Phenological Sequence for Integrated Landscape designated burning bush as an invasive plant. Rudy Haag burning Pest Monitoring bush (E. alatus ‘Rudy Haag’) is a nearly seedless cultivar that may Yan Chen* have a significant marketing advantage for nursery producers if data to Louisiana State University, Hammond, LA; [email protected] support a non-invasive character can be substantiated. Fruit display is Regina Bracy often promoted as a desirable characteristic in landscape ornamentals, Louisiana State University, Hammond, LA; [email protected] but prolific seed production is often cited as an indicator of invasive Dale Pollet potential. Preliminary observation indicated that cultivars of burning Louisiana State University, Baton Rouge, LA; [email protected] bush differ in fecundity under natural pollination conditions. The objec- tive of this project was to document the potential risk of ‘Rudy Haag’ Pest management in urban landscapes presents unique challenges burning bush as an invasive plant species based on seed production. E. because of the tremendous diversity of ornamental plants, each with alatus ‘Compactus’ and ‘Rudy Haag’ plants of a flowering size were its own complement of insect pests. As a result, pesticides are applied established in field plots at two locations, Lexington and Princeton, on a calendar rather than an “as needed” basis, causing unnecessary POSTERS–Monday KY. In Kentucky, both cultivars of burning bush flowers as plants are pesticide use and increased environmental risks. Plant phenology, leafing out in late April through May. Seeds mature by late fall and the study of the annual cycles of plant development and how these usually develop as a single ovule encased within a brightly colored cycles respond to seasonal changes in the environment, can be used aril inside a dry capsule. Under full sun conditions, ‘Compactus’ and as a tool to predict climate changes and pest activities in nurseries and ‘Rudy Haag’ produced an average of 1238 and 12 seed per plant, re- landscapes. A phenology research garden was established at the LSU spectively, across three years and two production sites. In Lexington, AgCenter Hammond Research Station in fall 2006. Thirty-five woody a 75% shade treatment was also included, but had no effect on seed flowering species were planted and monitored for major phonological production. ‘Compactus’ averaged 1514, 1061, and 240 seed per plant events during 2007. Flowering sequence of 15 species was documented. in 2005, 2006, and 2007; significantly fewer seed were produced in the Numerical phonological stages were developed for major species ac- last harvest year. ‘Rudy Haag’ plants produced no seeds the first year cording to BBCH principle. and an average of less than six in the subsequent two harvest years. Specified Source(s) of Funding: Louisiana EPSCoR Field and greenhouse pollination combinations (self-, intra-, and cross- pollinated) between ‘Compactus’ and ‘Rudy Haag’ were unsuccessful (212) Influence of Topdressing on Thatch with no subsequent seed development. In a simulated understory seed bank study using E. alatus ‘Compactus’, no germination occurred in Decomposition the field or under germination conditions following exhumation as Dustin S. Parker* compared to bush honeysuckle (Lonicera), which germinated readily Louisiana State University AgCenter, Baton Rouge, LA; dpark17@tigers. under both conditions. Burning bush seed had limited persistence in the lsu.edu soil with an estimated viability of 38%, 29%, 9%, and 2% after 3, 6, 9, Jeffrey Beasley and 12 months in soil, respectively. Minimal germination and limited LSU AgCenter, Baton Rouge, Louisiana; [email protected] persistence as well as extremely low seed production under natural Ron E. Strahan and supplemented pollination conditions support a low invasive risk Louisiana State University AgCenter, Baton Rouge, LA; of using E. alatus ‘Rudy Haag’ in landscape plantings. [email protected] Specified Source(s) of Funding: Departmental Edward Bush Louisiana State University, Baton Rouge, LA; [email protected] (210) The Effect of Mulch, Drip Irrigation, A common method to control thatch relies on sand topdressing. In field and Irrigation Supplement on Native Conifer trials sand-topdressing was shown to increase the relative humidity (RH) Establishment in Seattle Parks of bermudagrass thatch layer. Therefore, laboratory experiments were conducted to evaluate temperature and humidity effects on bermuda- Lisa Ciecko grass (Cynodon dactylon L.) thatch decomposition. Thatch samples University of Washington, Seattle, WA; [email protected] were subjected to 80%, 90%, 95%, or 100% relative humidity (RH) in Brandon Neuhaus small chambers at constant temperatures of 20 °C and 30 °C. Rates of University of Washington, Seattle, WA; [email protected] decomposition were measured through changes in CO2 evolution using Soo-Hyung Kim* gas chromatography. Thatch decomposition was accelerated at 95% and University of Washington, Seattle, WA; [email protected] 100% RH than 90% followed by 80% RH regardless of temperature.

HORTSCIENCE, VOL. 44(4), JULY 2009 1161 Also greater thatch decomposition occurred at 30 °C than 20 °C for files, zip codes, and land use polygons. Geographic Information System corresponding RH. Ultimately, this information will be used to develop (GIS) was used to create an integrated map for Albuquerque municipal models to help turfgrass managers design more efficient and effective limits. Clip, union, and spatial join GIS analysis tools were used to sand topdressing regiments to reduce thatch accumulation. create an integrated map. The maps’ attribute table had full information from all other layers. The integrated map gathered residential areas Specified Source(s) of Funding: Louisiana Turfgrass Association that shared the same income level. Samples of 400 residential units (213) Bermudagrass Establishment on Levees to are being selected randomly and stratified based on a zip code median income. ENVI FX 4.5 software will be used to extract different types Reduce Erosion and Nitrogen Losses of vegetation from high-resolution (0.15 m2) aerial photographs. Urban Robert Burwell* residential landscapes of Albuquerque will be categorized based on the LSU AgCenter, Baton Rouge, LA; [email protected] proportion of hardscape and softscape (vegetation cover). Historical Jeffrey Beasley evapotranspiration data will be used to calculate the water budget for LSU AgCenter, Baton Rouge, Louisiana; [email protected] different landscape categories. A user-friendly web-product is being Edward Bush built to allow residents and decision makers to determine water bud- Louisiana State University, Baton Rouge, LA; [email protected] gets for different landscape categories. Different scenarios of limited Ron E. Strahan moisture budget will be simulated to assess the vulnerability to drought Louisiana State University AgCenter, Baton Rouge, LA; associated with each specific landscape category. [email protected] Specified Source(s) of Funding: NOAA Steven Borst LSU AgCenter, Baton Rouge, LA; [email protected] (215) Linking Landscape Types to Water Use of Compacted clay soils are excellent materials for constructing levees Residential Urban Landscapes but without sufficient turfgrass coverage nutrient and soil erosion Rolston St. Hilaire will occur. This study examined the effect nitrogen source has to curb New Mexico State University; [email protected] runoff occurrence, severity and pollution throughout bermudagrass Malik G. Al-Ajlouni* establishment. Two N sources were applied, ammonium nitrate (quick New Mexico State University, Las Cruces, NM; [email protected] release) and sulfur coated urea (slow release). All N was applied as Worldwide, residential landscape types have emerged to conserve a single application at 49 kg/ha of N prior to common bermudagrass outdoor water use because of water shortages and the need for environ- (Cynodon dactylon L.) seeding. Rainfall was simulated at 96 mm/hr mental sustainability. Although many reports have mentioned various at 0, 2, 4, 6, 8, and 10 weeks after planting (WAP) with runoff from residential landscape types, none has provided robust classifications natural rainfall collected. Plots with higher bermudagrass coverage for residential landscape types and their associated water requirements. delayed runoff initiation and reduced runoff flow and erosion compared Our research seeks to classify typical residential urban landscapes and to more sparsely covered plots. At 10 WAP, bermudagrass reduced soil link each landscape type to a water requirement. The classification erosion by 90% and lateral water flow by 70%. The highest N-NO 3 theory of our research is based on plant water requirements, and the transport took place during the first 4 WAP with no differences in N ratios of landscape elements that need water versus elements that do source occurring. not. Nine landscapes in each of the six districts of Las Cruces, New Specified Source(s) of Funding: United States Army Corps/Jesco En- Mexico were selected using purposive sampling. In each district, the vironmental and Geotechnical nine samples were divided equally into three categories based on the ratio of landscape area that require irrigation. Google Earth 4.3, City of (214) Establishing a Decision Making Tool to Las Cruces online maps, and Microsoft Virtual Earth Beta were used to Reduce Drought Vulnerability in Residential Urban identify the landscapes. However, Global Positioning System will be Landscapes used to draw and accurately identify all landscape elements and areas in each sample. ArcGIS software will be used to identify the landscape Salman D. Al-Kofahi* elements and ratios. Estimation of landscape water requirements will New Mexico State University, Las Cruces, NM; [email protected] be based on reference evapotranspiration, plant factors, and landscape Gregg Garfin area. This classification will help landscape designers and planners University of Arizona; gmgarfi[email protected] identify designs that have specific irrigation requirements. Clyde W. Fraisse University of Florida; cfraisse@ufl.edu Specified Source(s) of Funding: NOAA Merrill Bean New Mexico State University; [email protected] Rolston St. Hilaire Horticultural Crops Culture and Management: New Mexico State University; [email protected] Sustainable Production Understanding residential landscape preferences has the potential to Monday, 27 July 2009 1:15–2:00 pm create a conceptual frame work that can guide drought management strategies. New Mexico urban landscapes are vulnerable to drought and urban landscapes in Albuquerque, New Mexico’s largest city, are (125) Tillage Impact on Water Use and Yield of no exception. The main objectives of this study were to establish a Three Sweet Corn Cultivars scientifically-based categorization of urban landscapes and to use this Wayne Whitehead* knowledge of urban landscape categories to assess their vulnerability to Fort Valley State University, Fort Valley, GA; [email protected] drought. We obtained Albuquerque’s Geographic Information System (GIS) data presented in Environmental System Research Institute (ESRI) Bharat P. Singh shape files. These files included parcel base maps, municipal limits shape Fort Valley State University, Fort Valley, GA; [email protected]

1162 HORTSCIENCE, VOL. 44(4), JULY 2009 The purpose of this study was to evaluate how tillage practices influenced The goal of this study was to compare the effect of tillage on above- water use (WU) and yield of sweet corn. The tillage and cultivar treat- ground biomass (AGB) yields and leaf area index (LAI) of six sweet ments were applied in a factorial experiment using randomized complete corn cultivars. The tillage and cultivar treatments were applied in block design with three replications. Cultivars comprised of Silver King factorial arrangement using randomized complete block design with (C1), Avalon (C2), Argent (C3) while tillage treatments consisted of three replications. Cultivars included Silver Queen (C1), Silver King no-till (NT) and strip-till (ST). Sweet corn was planted in spring 2008. (C2), Frosty (C3), Avalon (C4), Silver Princess (C5), Argent (C6) Sweet corn ears were harvested seventy-six days after planting. Four and tillage treatments consisted of no-till (NT) and strip-till (ST). In bi-weekly (13 June = vegetative, 27 June = early tasseling, 11 July = spring of 2008, six sweet corn cultivars were planted in the field. AGB silking, and 23 July = mature ear) volumetric soil water percentages was collected three weeks prior to harvest while LAI was recorded at were measured at a depth of 0–45 cm. Maximum marketable sweet vegetative (10 June), early tasseling (26 June) and harvest week (16 corn fresh yield (19.5 Mg/ha) was produced by ST-C2 while minimum July). ST-C1 produced highest LAI at vegetative (2.23), early tasseling yield (15.7 Mg/ha) was produced by NT-C3. Among the three sweet (3.39) and harvest week (4.00). Lowest LAI at vegetative (1.12) and corn cultivars over all dates, WU was highest for C1 grown in ST and early tasseling (1.24) were produced by NT-C6, while NT-C3 produced lowest for NT-C3. Results indicated that C2 (cv. Avalon) in strip-till lowest LAI during harvest week (1.45). Maximum sweet corn AGB had highest yield and third highest water use while C3 (cv. Argent) in fresh (38.3 Mg/ha) and dry weight (7.1 Mg/ha) yields were produced no-till was lowest yielding with lowest WU. by ST-C1 while minimum AGB fresh (7.8 Mg/ha) and dry weight (2.0 Specified Source(s) of Funding: Evans-Allen Mg/ha) yields were produced by NT-C3. First year results showed that C1 (cv. Silver Queen) grown in strip-till produced highest AGB (126) Growing Conventional and Organic Squash yields and LAI, while C6 (cv. Argent) and C3 (cv. Frosty) in no-till with Black Plastic or Straw Mulch and Transitional had lowest LAI with minimal AGB yields. Squash with Living Mulch Specified Source(s) of Funding: Evans-Allen Elizabeth Maynard* Purdue University, Westville, IN; [email protected] (128) Impact of Brassica Cover Crops on Eggplant Sustainable vegetable production systems require alternatives to pe- Transplant Growth and Muskmelon Seed troleum-based plastic mulch and intensive tillage. This work evaluated Germination Under Field Conditions the performance of squash in three systems: organic (O), conventional Victoria Ackroyd* (C), and reduced tillage with living mulch in transition to organic (TR). Michigan State University, East Lansing, MI; [email protected] POSTERS–Monday Treatments in each trial were replicated three times in a randomized block design. In O and C trials, the main plot treatments were black plastic Mathieu Ngouajio (PL) and straw (ST) mulch. In TR, they were living mulch mowing Michigan State University, East Lansing, MI; [email protected] heights of 15 (S) or 30 cm (T). Subplots were cultivars: ‘Cash Flow’ A field experiment was conducted at the Southwest Michigan Research (CF), and ‘Costata Romanesca’ (CR). The trials were established in and Extension Center in Berrien County, Michigan in the summer 2007 on sandy loam soil at a University research farm in Wanatah, IN. of 2008 to determine the effects of three Brassica cover crops on In May, cover crops of hairy vetch and winter rye (O) or winter wheat eggplant and muskmelon growth and yield. The treatments consisted (C) were incorporated, and in TR strips 1.8-m wide on 2.4-m centers of oilseed radish (20 lbs/acre), yellow mustard (9 lbs/acre), Oriental were tilled into white clover sod. Squash (3227 plants/ha in C and O; mustard (8 lbs/acre), methyl bromide (the positive control), and no 3630 plants/ha in TR) were transplanted June 12-14, and straw mulch treatment (the negative control). The experiment used a randomized applied in the row for ST, S, and T treatments within 3 days after plant- complete block design with 6 replications. Methyl bromide (400 ing. Yield of marketable squash 15 to 28 cm long harvested between lbs/acre 50:50 methyl bromide:chloropicrin) was applied in mid May. July 7 and Aug. 31 did not differ between PL and ST (PL 4.4 vs. ST The cover crops were planted on 4 April, then disked and tilled into 3.4 kg/plant in C, and PL 3.3 vs. ST 3.5 kg/plant in O) or between S the soil on 3 June, after which black plastic mulch was immediately (2.9 kg/plant) and T (3.0 kg/plant). Marketable yield in kg/plant did not put in place. Eggplant seedlings were transplanted and muskmelon differ between cultivars. CF produced greater numbers of marketable seeds were direct-seeded into the beds on 10 June. Plots were evalu- fruit than CR in C (CF 17.2 vs. CR 11.0 fruit/plant) and TR (CF 12.8 ated for stand count, transplant height, and Verticillium wilt incidence vs. CR 8.9 fruit/plant), and a similar trend occurred in O (CF 14.7 vs. based on a subjective score of 1 to 10 (1 being ‘dead’ and 10 being CR 11.2). Soil nitrate-N in the surface 15-cm dropped sharply by mid- ‘no disease’). The eggplant in the yellow mustard plots consistently July in all mulch treatments except O PL. Leaf nitrogen content for CF had the lowest subjective scores (indicating more disease). Although in mid-July and mid-Aug. averaged 3.7% in C, 4.7% in O, and 3.9% eggplant stand was not affected, transplant height was generally reduced in TR. Pest problems that were not successfully managed in O and TR in the cover crop plots early in the season. Further, the cumulative plots included squash vine borer and Plectosporium Blight. The O and yield of grade 1 eggplant was significantly less in the yellow mustard C systems performed acceptably but the TR system needs substantial plots than in the methyl bromide and no treatment plots. Muskmelon improvement before it can be recommended. These results should aid stand counts were reduced in the cover crop plots. Melon stand was in decision-making as growers look for more sustainable practices. 0%, 12%, and 40% for oilseed radish, Oriental mustard, and yellow Specified Source(s) of Funding: Purdue University mustard, respectively, compared to 100% for the methyl bromide plots and the untreated control plots. The results suggest that the use (127) Influence of Tillage on Leaf Area Index and of these three cover crops is not advisable in systems where the cash Aboveground Biomass Yields of Six Sweet Corn crop will be direct seeded immediately after tilling the cover crop Cultivars into the soil. Additional studies are needed to determine a safe period of time between cover crop incorporation into the soil and cash crop Wayne Whitehead* seeding, and to determine the susceptibility of cash crop cultivars to Fort Valley State University, Fort Valley, GA; [email protected] cover crop residue. Bharat P. Singh Fort Valley State University, Fort Valley, GA; [email protected] Specified Source(s) of Funding: USDA

HORTSCIENCE, VOL. 44(4), JULY 2009 1163 (129) Applied Allelopathy: Effects of Daffodils on Marcelino Bazán-Tene Other Species in Sustainable Agriculture and the Universidad de Colima, Tecomán, Col.; [email protected] Home Landscape Jaime Molina-Ochoa Universidad de Colima, Tecomán, Col.; [email protected] Sonja Lallemand* Missouri State University, Mountain Grove, MO; Lallemand26@missou In Western Mexico, several organic wastes such as molasses, cattle ristate.edu manure, sugarcane bagasse, crop residues (banana, rice, sorghum, and maize), lemon shell, and coffee pulp have become a source of environ- Martin Kaps mental contamination. Their use is a viable alternative in vermicompost Missouri State University, Mountain Grove, MO; [email protected] production by earthworms as a profitable activity for many producers and for soil amendment. However, there are not available research Frank Einhellig results about the effects on physical and chemical properties in acid Missouri State University, Springfield, MO; frankeinhellig@missourista soils. This work evaluates the effects of commercial vermicompost, te.edu produced from coffee pulp on some physical and chemicals properties The purpose of this study is to investigate which plants can be grown in an acid soil. The experiment was carried out under greenhouse con- successfully with daffodils as follow-up crops for small farmers or as ditions, in PVC columns 7.5 cm diameter and 60 cm long containing plantings to cover senescing foliage of daffodil bulbs for landscapers. samples from the upper layer 0–0.30 m of a medium-textured, typic Other investigators have shown that Narcissi spp. have allelopathic oxisol, collected in a cultivated sugarcane area in the Matatipac Val- effects due to alkaloids they produce. They identified Narciclasine, a ley, Nayarit, Mexico. The preliminary soil chemical analyses showed compound isolated in the mucilage of Narcissus bulbs, as one cause of the following parameters: pH 4.9, OM content 0.80% and EC 0.130 inhibitory effects on growth and plastid development in excised radish dS/m. While vermicompost of coffee pulp had: OM content 49.38%, cotyledons. In the present study, four varieties of Narcissi: N. tazetta pH 5.81, total C 28.64%, total N 2.44% and total P 3729 ppm. Five ‘Paper-white’, N. jonquilla ‘Quail’, Narcissus ‘Ice Follies’, N. tazetta levels of vermicompost (equivalent to: 0, 20, 40, 60, and 80 ton/ha, ‘Thalia’ were used. Greenhouse and field experiments were conducted dry weight) were evaluated during 120 days and sampled each 30 days to evaluate the effects of leaf leachate or plant residue of Narcissus on under a complete randomized design with four replicates. Physical growth and development of landscape plants and herbs that included properties of the soil such as porosity percent, particle density and bulk Antirrhinum nanum ‘Frosted Flames’ (snapdragon), Callistephus chi- density were determined by specific gravity bottle method and cation nensis ‘Powder-puff’ (Chinese aster) , Coleus scutellarioides ‘Dragon exchange capacity was estimated by ammonium saturation method. Sunset’ and ‘Volcano’ hybrids (Coleus), Cosmos sulphureus ‘Polidor’ Chemical parameters such as pH, organic matter (OM), C, electrical (Cosmos), Ocimum basilicum ‘Genovese’ (basil), O. basilicum ‘Let- conductivity, available nitrogen, phosphorous, potassium, Al and Fe tuce Leaf’ (basil), Petroselinum neapolitanum (Italian parsley), Zinnia were determined. Results shown that the porosity, particle density and elegans ‘Envy Double’ (Zinnia), and Fragaria vesca ‘Mignonette’ bulk density values were not affected by vermicompost application. (strawberry). In pot studies germination of seeds of snapdragon, was On the contrary, the casting application reduce pH levels in soil with reduced by 60 to 80% and delayed by 14 to 25 days when planted with 40 and 80 ton/ha compared with control (0 ton/ha). OM was increased N. tazetta ‘Paper-white’. Leaf residues of N. jonquilla ‘Quail’ and N. (0.28%) in acid soil columns only the first 30 days after worm casting ‘Ice Follies’ caused up to 50% stunting of the Coleus varieties, and application. Electrical conductivity was increased in all soil columns some chlorosis was observed in the leaf blades of C. scutellarioides. enriched with vermicompost at the 30 and 60 days. Finally Al and Fe In pots planted with N. jonquilla ‘Quail’ and N. ‘Ice Follies’ and contents showed difference between treatments. Important changes placed outside the greenhouse, airborne weed seeds did not germinate concerning the nutrimental and chemical characteristics in acid soil in the undisturbed pots, compared to pots without Narcissus that had due to the coffee pulp worm casting application were observed. extensive weed growth. In a field experiment co-planting of Narcissus with several of the summer annuals and herbs, the greatest effects were Specified Source(s) of Funding: Universidad de Colima observed on basil. Transplanted basil seedlings had reduced growth and (131) Application of Doses of Vermicompost in a fresh weight in the presence of N. ‘Ice Follies’ and N. tazetta ‘Thalia’ bulbs, and several of the basil plants exhibited chlorosis. Transplanted Saline Soil on Chili (Capsicum annuum L.) Plant seedlings of Cosmos and Zinnia in the presence of Narcissus were slow Growth Under Greenhouse Conditions to reach flowering stage when compared to the absence of Narcissus. In Zaira Araceli Barreto-Curiel field co-plantings, no negative effects were observed on Chinese aster, Universidad de Colima, Tecomán, Col.; [email protected] strawberry, and parsley. The evidence indicates that Coleus and basil José Gerardo López Aguirre* would not be suitable as follow-up planting after Narcissus spp. Universidad de Colima, Tecomán, Col.; [email protected] Specified Source(s) of Funding: Missouri State University Javier Farias-Larios Universidad de Colima, Tecomán, Col.; [email protected] (130) Use of Vermicompost and Their Effect on Marcelino Bazán-Tene Physical and Chemical Properties in An Acid Soil Universidad de Colima, Tecomán, Col.; [email protected] Ernesto Arturo Domínguez-Camarena Salvador Guzmán-González Universidad de Colima, Tecomán, Col.; [email protected] Universidad de Colima, Tecomán, Col.; [email protected] Javier Farias-Larios The intensive farming and excessive irrigation, uncontrolled, with water Universidad de Colima, Tecomán, Col.; [email protected] containing high salts concentrations, originate serious problems of Arnoldo Michel-Rosales salinization in soils and their improvement is a big problem for produc- Universidad de Colima, Tecomán, Col.; [email protected] ers. Is necessary to look for new alternatives to saline soils improve- ment, some alternatives are organic products, as vermicompost. It is José Gerardo López Aguirre* recognized that vermicompost provides a better soil structure, porosity Universidad de Colima, Tecomán, Col.; [email protected] and moisture retention capacity and a large amount of nutrients. The

1164 HORTSCIENCE, VOL. 44(4), JULY 2009 objective of this study was to evaluate the application of vermicompost Merritt Taylor doses in a saline soil and chilli (Capsicum annuum L.) plant growth Oklahoma State University, Lane, OK; [email protected] under greenhouse conditions. This work was carried out in Tecomán, Cowpea is important to a diversity of farmers in the U.S. central plains. Colima, located in the Central Pacific Coast in México, in the Facultad Current weed control practices for cowpea production typically involve de Ciencias Biológicas y Agropecuarias, Universidad de Colima. Soil the use of synthetic herbicides. Increasing interest in organic crop samples were taken from a farm located at 20 Km from the Campus production in the region creates a need for alternative weed control where the study was done. Doses used were 0 (T), 25 (T ), 50 (T ), 75 2 3 techniques that are consistent with the requirements of the USDA Na- (T ) and 100 (T ) vermicompost g/kg of soil with 15 replications. In 4< 5 tional Organics Program. Corn gluten meal (CGM), a by-product of the the original soil the following chemical analysis were done: pH, organic corn milling process, has been shown to control weeds at the time of matter, electrical conductivity and soluble anions and cations. When seed germination. Its use as a weed control material has already been these chemical analyses were done, soil was leached to decrease salt explored for several vegetables. The current project evaluates the use of concentration, and, after leaching, the same chemical determinations CGM in cowpea as part of a weed management program that includes were carried out to the soil samples. Chili (Capsicum annuum L.) mechanical cultivation and manual weed removal measures. In 2006 plants were used. Plant height was measured each 7 days. At the final and 2008 cowpea was direct seeded at Bixby, Oklahoma on a Severn of the experiment, also were measured leaf area, fresh and dry weight very fine sandy loam soil. Immediately following seeding CGM was of roots and aerial. Data were analyzed using SAS program. Results applied at either 2178 or 6534 lb/acre to the soil surface. At each CGM showed that vermicompost application had beneficial effects on pH and rate, applications were made using two methods: a solid band over the organic matter, because was decreased and increased respectively, but row (solid) or a band that had a narrow strip just above the seed row that electrical conductivity was increased, respecting to soil after leaching. remained untreated (banded). Another treatment (herbicide) used the The statistical analysis showed that the variables analyzed had their herbicides Dual Magnum (0.75 lb ai/acre) and Pursuit (0.063 lb ai/acre) highest values in treatment T , both the chemical analysis and crop 5 applied preemergence. A sixth treatment did not receive herbicide or parameters, as foliar area and height, where differences were statisti- CGM (weedy). These treatments were cultivated and hoed once crop cally significant (P ≤ 0.05), observing also that in the same treatment growth and weed size were sufficient to perform these procedures. In had a survival of 100%. Our conclusions are that the application of a seventh treatment, (weeded), weeds were removed manually while vermicompost to a leached saline soil decrease pH and increases soil very small throughout the course of the study. Prior to performing the organic matter concentration, then, the application contributes to that cultivation and hoeing procedures, percent weed control was estimated crops have a growth better, but we must to take in count that electrical for all CGM and herbicide treatments. The time requirement for cul- conductivity could be increased.

tivation and hoeing was determined for each treatment. Plots were POSTERS–Monday Specified Source(s) of Funding: Universidad de Colima harvested at maturity to estimate cowpea yields. Yields did not differ significantly among treatments for either year for the study. (132) A Spacing Calculator for Mixed Plantings Michael Bomford* (134) Enhanced Forage Production from Triticale Kentucky State University, Frankfort, KY; [email protected] and Triticale–Pea Mixtures The most appropriate way to compare mixed plantings to pure stands Kurt Nolte* is a matter of debate, but a consensus has emerged that mixed plant- University of Arizona, Yuma, AZ; [email protected] ings tend to be more productive. Few horticulture extension materials Guangyao (Sam) Wang offer practical advice for designing mixed plantings. One exception, a University of Arizona, Maricopa, AZ; [email protected] popular series of gardening manuals promoting biointensive produc- Nancy A. Elliott tion, recommends that plant spacing in mixtures be set to the mean Elliott Plant Breeding, Yuma, AZ; [email protected] of monoculture spacing recommendations for component crops. In The desert regions of the lower Colorado River Valley is home to most cases this results in a lower plant density in mixtures than in over 300,000 acres of winter vegetables. While most producers in the segregated pure stands, reducing the likelihood of realizing a mixture region typically produce a spring winter wheat, melon or cotton crop yield advantage. An improved method for calculating mixture spacing following winter vegetable harvest, many seek alternative cropping is proposed that sets total plant density in mixed plantings equal to the schemes that fit within the winter vegetable rotation. And, although combined density of segregated pure stands. This method is intended to alfalfa is the single most important field crop grown along the Colorado allow meaningful comparisons of mixtures to pure stands, and increase River, many desert southwest alfalfa producers either graze sheep on the likelihood of realizing a yield advantage from mixed planting. The slow growing alfalfa fields or let them lie inactive during the 4-month method derives mixture spacing recommendations from monoculture winter period. Intercropping field peas with cereal grains for forage has spacing and the proportion of the mixture accounted for by each crop. great potential for winter production in the desert areas as the protein A mixture spacing calculator that uses the method is available online benefits of peas in pea/cereal mixtures has been shown to produce bet- at http://organic.kysu.edu/CompanionSpacing.shtml. ter quality silage than cereals alone in the upper Midwest and Canada. (133) Evaluation of Corn Gluten Meal for Weed A spring triticale variety (Companion) and 2 winter triticale varieties Control in Cowpea (Blizzard and Wintersiris) were grown in small plot trials either alone or intercropped with a forage pea (var. Mittry) to test the notion that James Shrefler* pea/cereal intercropping may have certain advantages when grown for Lane, OK; jim.shrefl[email protected] livestock feed. In mixed crop treatments, peas represented an average of Lynn Brandenberger 22% of the seeds present at seeding. Following the first harvest, yields Oklahoma State University, Stillwater, OK; lynn.brandenberger@okstate. of intercropped triticale/pea were not significantly different from the edu cereal alone, but both out yielded alfalfa grown alone during the same Charles Webber time frame by over 4.2 fold. Although forage peas did not significantly USDA - ARS So. Central Agric. Res. Lab, Lane, OK; cwebber- enhance the Relative Forage Value (RFV) of pea/cereal mixtures, in- [email protected] tercropping produced results that were similar to that of alfalfa alone.

HORTSCIENCE, VOL. 44(4), JULY 2009 1165 The success of these intercrops seems to be highly dependent on the (35) The History and Evolution of Longwood seeding rates for both crops. From our preliminary results, when peas Gardens’ Research Program form at least 20% of the sown mixture (by weight), we found crude protein in the harvested forage to be 2 to 4 percentage points higher Matthew D. Taylor* than with pure cereals. Acid detergent fiber (ADF) content did not vary Longwood Gardens, Kennett Square, PA; [email protected] significantly between mixtures and pure cereals, but neutral detergent Longwood Gardens is a premier display garden in Kennett Square, fiber levels are 2 to 4.5 percentage points lower in mixtures, resulting Pennsylvania. The Gardens began in 1906 when Pierre S. duPont in a higher feed intake potential. (1870–1954) purchased 202 acres (currently 1040) that was known as Peirce’s Park. Dr. Roger Seibert took over as the first director of Longwood Gardens in 1955 and began the Longwood research program that pertained to horticultural displays. New and exotic plant material Computer Applications/Consumer Horticulture was regularly arriving at Longwood through plant exchanges and plant Tuesday, 28 July 2009 12:00–12:45 pm explorations to faraway places such as South America and the Hima- layas. To grow and evaluate new accessions, Longwood established a nursery in 1956 and built four research greenhouses in 1958. In 1960, (34) Benefits and Impact of OSU Master Gardener under the direction of Dr. Richard Lighty, a plant breeding program Program was initiated. Through plant exploration, plant trials and breeding, Weston Miller* Longwood has named and released over 130 cultivars. In addition to Oregon State University, Oregon City, OR; weston.miller@oregonstate. evaluating and breeding new plants, Longwood also conducts research edu to establish and improve growing and propagation techniques for plants Gail Langellotto in the garden displays. To assist with these goals, a plant tissue culture Oregon State University, Oregon City, OR; Gail. laboratory was established in 1999. Longwood’s research mission was [email protected] and will continually be directed at improvement and advancement of the art and science of horticultural display. Recently, the research It is important to collect information on the motivators and attitudes mission at Longwood Gardens has evolved to include more in-depth that influence individual volunteers within OSU Extension Service and far-reaching research projects. This will be accomplished through Master Gardener Program. A statewide survey of the OSU Master sound experimental design; increased publication in trade magazines, Gardener Program was conducted in 2007, to assess the benefits that scientific journals, newsletters and via the Internet; increased presen- volunteers receive from their participation in the Program as well as tations of results at professional forums; and further development of the impacts of the Program on volunteers’ attitudes and garden man- meaningful collaborations. Currently, research at Longwood is being agement practices. Invitations to fill out the survey were extended to conducted in areas of breeding, propagation, nutrition, tissue culture, 3391 Master Gardeners. Each survey consisted of a series of statements and environmental physiology. that respondents could score on a Likert scale. Fifteen statements were used to assess volunteers’ motivation for participating in the Master (36) Utilizing Master Gardeners as Extension Gardener Program. An additional 13 statements were used to assess the Educational Material Editors impact of the OSU Master Gardener Program on volunteers’ sustainable gardening practices. Statements used to assess volunteers’ motivation Lelia S. Kelly* were identical or similar to those used by Schrock et al. (2000) in a Mississippi State University Extension Service, Verona, MS; leliak@ext. msstate.edu survey of Missouri Master Gardeners. Statements used to assess the impact of the OSU Master Gardener Program on volunteers’ sustain- In recent years the trend to “downsize” many state’s Extension bud- able gardening practices were identical or similar to the statements gets and personnel has resulted in fewer Extension professionals with used by McMahan and Cowen (unpublished data) to survey Master fewer resources to meet the continued demand for home horticulture Gardeners in Yamhill County and Baker County, OR in 2004. A total information. Meeting the need for this information has required new of 781 Master Gardeners responded to the survey, for a response rate and unique approaches. Master Gardeners have long been involved in of 23% The mean Likert value of statements used to examine the the traditional role of assisting county offices with the delivery of home perceived benefits of being an OSU Master Gardener volunteer varied horticulture programs and materials. In many cases, the programs and from 3.15 (equivalent to ‘neither agree or disagree’) to 4.76 (equiva- information delivered were developed primarily or solely by Master lent to ‘strongly agree’). Respondents identified increased access to Gardeners. The result has been factsheets, pamphlets, PowerPoint, information or increased knowledge and understanding as the great- and other program material of professional quality. For the consumer est benefits of being a Master Gardener volunteer (range of means = horticulture specialist/state master gardener coordinator determining 4.25 to 4.76). Secondary benefits included opportunities for personal new and more efficient ways to utilize the talents and resources of these growth (range of means = 3.66 to 4.56). The mean Likert value of volunteers and “capturing” the abundant amount of material already statements used to examine the impact of the Oregon State University generated and used by Master Gardeners was a natural solution to the Master Gardener Program on respondents’ gardening practices and “downsizing” problem. To address the need to revise the backlog of attitudes varied from 4.01 (equivalent to ‘agree’) to 4.52 (equivalent outdated home horticulture publications and the need to develop more to ‘strongly agree’). Master Gardeners report that they have shared educational program material for the public, the consumer horticulture their gardening knowledge and techniques with others in the preced- specialist partnered with the Mississippi Master Gardener Association to ing year (Likert mean = 4.56). These results suggest that recruitment establish an Education Committee. This committee which consisted of and retention of OSU Master Gardeners will be best when programs a chairperson and 11 members was given two objectives. These objec- continue to offer a variety of high quality training opportunities to tives were to assist the consumer horticulture specialist by acting as 1) both new and continuing Master Gardeners. Such programs have the revision editors of the outdated home horticulture publications and 2) capacity to positively influence Master Gardener’s knowledge and to compile, edit, review, and convert to electronic format educational practice of sustainable gardening techniques. materials that had been developed and delivered by Master Gardeners statewide. The end result of the second objective would be to have these

1166 HORTSCIENCE, VOL. 44(4), JULY 2009 educational materials available online through a password protected favored by exhibition rose enthusiasts in lower southeastern US for website for use by Mississippi Master Gardeners and Extension profes- vigor and performance. Thirteen cultivars are grafted on ‘Dr. Huey’ sionals. Through the process of compiling existing materials any home rootstock, of which 1 is a Grandiflora (Gr), 3 are Floribunda (F), and 9 horticulture topic areas that were deficient in information would be are HT roses. ‘Dr. Huey’ rootstock is a common understock for roses, targeted by the committee and specialist for future development. particularly in hot climates. Three cultivars are on their own root, of which 1 is a F and 2 are S. Plants range from 2 to 6 per cultivar. Data Specified Source(s) of Funding: Department, College, State and/or on plant height, plant width, number of canes per plant, and ratings for HATCH and association. black spot, incorporating both defoliation and infection, were collected (37) Technologies for Creating Efficient Workflow at end of growing seasons in 2007 and 2008 in November. Horsfall- Barratt rating scale was used to generate scores for black spot. In 2008, Between 2-D AutoCAD Drawings and 3-D SketchUp end of season visual plant performance was assessed by rating flower Models in the Preparation of Planting Plans quantity and quality, foliage quantity and quality, and plant habit and Michael Mohney* vigor on a scale of 1 to 10. Cluster analysis shows less distinct patterns Pennsylvania State University, University Park, PA; [email protected] for height and width for the combined 2007/2008 data than 2007 data Dan Stearns alone for cultivars regarding rootstock, suggesting that growth differ- Pennsylvania State University, University Park, PA; [email protected] ences become less with time and maturity. One-way ANOVA, run on combined data, shows a range of cultivar differences, but interpretation is Martin McGann difficult due to the nature of the collection. Pearson correlation analysis Pennsylvania State University, University Park, PA; [email protected] reveal significant correlation between mean overall plant performance Landscape planting designs are commonly created in two-dimensional and blackspot for cultivars on ‘Dr. Huey’ rootstock (r = –0.60) and R. plan view using AutoCAD or other similar software applications. xfortuniana rootstock (r = –0.61). One-way ANOVA, separately ana- Drawings produced by these programs provide detailed information lyzed by rootstock type, shows cultivar differences within rootstock on horizontal placement of site elements, but offer little to designers selection. This research project supports our expanding research program or clients regarding the three-dimensional spatial relationships that are combining the best cultivars and environmentally sound, sustainable critical to successful designs. Three-dimensional models created using techniques to produce better roses for Southern gardeners. We will Google SketchUp or other similar applications provide designers and continue to display cultivars grown on both rootstocks and on their clients with realistic virtual sites that can be viewed from an infinite own roots to demonstrate a wide range of rose choices for gardens and number of viewpoints. Both AutoCAD and SketchUp can be used for landscape uses, and to understand what genetic and production forces landscape design development, but each has a unique user interface shape the growth habits of roses. and output. Methods for movement from one platform to the other are desirable, but are not well documented. With a combination of Specified Source(s) of Funding: Department of Plant and Soil Sciences, application commands and plug-ins from external sources, workflow Mississippi State University, Mississippi between platforms is enhanced. (40) An Analysis of Species Selection and Acquisition (38) Multipshot Techniques to Use with Digital Practices by Community Tree Planting Programs Cameras for Optimizing Horticultural Photography Daniel C. Burcham* James McConnell* University of Delaware, Newark, DE; [email protected] University of Guam, Mangilao; [email protected] Robert Lyons University of Delaware, Newark, DE; [email protected] Digital cameras have improved greatly over the last five years with improved sensors with higher resolution. Processing speed has also Community tree planting programs, often managed by non-profit or- increased allowing use of bracketing techniques to record sequences ganizations or municipalities, improve communities with tree planting POSTERS–Tuesday of images within a short period of time. These multishot techniques and management that frequently includes volunteer support. A recent make it possible to combine images to produce images that can have focus of these programs is to increase the diversity of trees in the urban greater resolution, dynamic range, depth of field and field of view. landscape to mitigate the risks associated with over planting, includ- Use of these techniques for optimizing photographs of plants and ing devastating losses to species-specific landscape pests. However, landscapes are described. Suggested workflow and various software a limitation frequently mentioned by practitioners is an insufficient applications are presented. species mixture available within nurseries. This study examined the tree selection and acquisition process in order to identify key orga- Specified Source(s) of Funding: USDA Hatch nizational components contributing to tree planting goal attainment. (39) Growth Performance of Rose Cultivars in Research included eleven, qualitative, key informant interviews with community tree planting program managers in the Northeast and Mid- Raised Brick Beds Atlantic United States. Semi-structured interviews yielded data at each Pamela Collins* organization, and transcribed verbal qualitative data was analyzed at Mississippi State University, Mississippi State, MS; [email protected] the response level. Additional data gathered during this study included state.edu approved species lists, site assessment checklists, contract specifications, Ekaterina Jeliazkova and tree planting totals for 2008. Participating organizations reported Mississippi State University; [email protected] an aggregated total of 26,383 trees planted during 2008, with the range Dennis Rowe of total planting activity between 44 and 21,025 trees during that same Mississippi State University, Starkville, MS; [email protected] year. Zelkova serrata, Gleditsia triacanthos var. inermis, and Styphnolo- bium japonicum were the three most frequently planted species among Thirty cultivars were planted in 2006 in a new formal rose display participating organizations during 2008. Prunus (14.91%), Quercus garden, and 2 cultivars were added in 2007. Sixteen cultivars are (11.45%), and Zelkova (8.53%) were the most frequently planted genera, grafted on R. ×fortuniana rootstock, of which 1 is a Shrub (S) and 15 and the most heavily planted families included Roseaceae (22.59%), are Hybrid Tea (HT) roses. Cultivars on R. ×fortuniana rootstock are Fagaceae (11.67%), and Ulmaceae (11.14%). The species selection

HORTSCIENCE, VOL. 44(4), JULY 2009 1167 process frequently begins with the consideration of an approved species fruit; 2) possible removal of cuticle by the alkaline wash may cause list. Organizations reported a combined total of 97 species approved for increased water loss, as seen on mango; and 3) the alkaline washed planting in their geography, and these approved species lists included, fruit surface allowed better coating adhesion to the fruit surface, thus, on average, 77.97% of all species planted by participating organiza- application of coating after an alkaline wash always had lower gas tions during 2008. Findings indicate a variety of selection processes transmission rate in both mango and carambola fruit compared to coat- and criteria utilized to identify appropriate species for communities. ing alone or untreated controls. Another study showed that an alkaline Emphasized selection criteria included a species’ native range, stress wash significantly improved fruit sanitation by removing of surface tolerance, mature size, and aesthetic characteristics, all of which microbial organisms and spores. However, care must be paid to avoid contributed to the final mixture of species sought by the organization phytotoxicity due to the high pH treatment. for planting. However, the ranking of these selection criteria varied significantly among participating organizations. Additionally, programs (102) Effect of Controlled Atmosphere, 1-MCP and supporting community involvement and input in tree selection reported Preconditioning Treatments in the Development of greater success with the tree acquisition process. Approved species lists, Physiological Disorders in ‘Honeycrisp’ Apples site assessment checklists, nursery specifications, and tree installation Carolina Contreras* specifications were frequently reported as organizational components Michigan State University, East Lansing, MI; [email protected] that supported the achievement of tree planting goals. Participants interacted with nurseries primarily through traditional and personal Randolph Beaudry communication, although some organizations utilized bid solicitation Michigan State University, East Lansing, Michigan; [email protected] or contract growing to obtain species from nurseries. ‘Honeycrisp’ apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Specified Source(s) of Funding: Longwood Graduate Program, Univ. Mansf.] fruit is susceptible to the storage disorders soggy breakdown, of Del. soft scald, bitter pit, lenticel breakdown and internal browning. The effect of atmosphere (in percent, O2/CO2 combinations of 1/0; 3/0; 1/3; 3/3; 20.5/0.5; and 20.5/3), 1-MCP application (1 ppm in air storage only), and preconditioning (3 and 5 days at 20 °C before storage in air) Crop Physiology/Physiology: were studied. Apples from four different orchards were evaluated after 1, 3, and 6 months storage at 3 °C. The treatments 1/3 and 3/3 yielded Postharvest 2 (Poster) the highest incidence of internal browning. Also, the treatment 1/0 Tuesday, 28 July 12:00–12:45 pm caused internal browning incidence in all orchards, although at a low rate. Regular atmosphere (20.5/0.5) treatments reduced or eliminated disorder incidence. 1-MCP and preconditioning did not enhance disor- (101) Effect of An Alkaline Surface Treatment on der development in air storage fruit. No treatment effect was detected Edible Coating Performance as Pertains to Gas and for soft scald, bitter pit and lenticel breakdown incidence. Firmness, Water Vapor Exchange of Carambola and Mango soluble solids content, and red coloration of skin were not affected by Fruit treatments. Background color was affected by controlled atmosphere leading to greener apples. 1-MCP reduced internal ethylene concentra- Jinhe Bai* tion (IEC), but had little effect on firmness. Preconditioning did not USDA–ARS, Citrus & Subtropical Products Lab, Winter Haven, FL; reduce firmness retention as has been previously reported. [email protected] Jan Narciso Specified Source(s) of Funding: Michigan agriculture experiment USDA/ARS Citrus and Subtropical Products Lab, Winter Haven, FL; jan. station [email protected] (103) Production and Quality of Strawberry Fruits Elizabeth Baldwin USDA–ARS, Citrus & Subtropical Products Lab, Winter Haven, FL; liz. In Vitro Plants Cultivar ‘Chandler’ Treated with [email protected] Gibberellic Acid Freshly harvested ‘Keitt’ mangoes and ‘Arkin’ carambolas were washed Maria De Camacaro* with or without alkaline solution and then coated with carnauba wax or Universidad Centroccidental Lisandro Alvarado, Cabudare Estado Lara; water. After treatments, fruit were stored at 15 °C and relative humidity [email protected] 70% room for 2 days to allow drying of the coating and equilibration Norca Mogollon of the internal gas in the fruit. Stabilized fruit, average weight 522 g [email protected] for mango and 153 g for carambola, were individually sealed in 3.6-L Maritza Ojeda glass jars initially flushed with dry air and incubated for up to 8 hours. Aracelis Gimenez RH in the jars was measured at 1 min. intervals to determine water loss. In Venezuela the production areas are limited by the temperature For CO2 and O2 transmission determination, internal gas components were measured two and four days after treatment. The results showed requirements for this reason, they are located at 1000 MSL where the that the alkaline wash slightly increased water loss in mango fruit, temperature ranges are considered adequate for the growth and fruit but decreased water loss in carambola fruit while coating the fruit production of strawberry. In order to compensate the temperature re- remarkably reduced water loss. In addition, coating application on the quirement and increase the production areas, in this country, the aim of alkaline washed fruit had a lower water loss rate than coating alone. this research was to evaluate the effect of exogenous gibberellic acid on production and quality fruit in ‘Chandler’ strawberry (Fragaria Similar results were observed for CO2 and O2 gas exchange. Both the alkaline wash and coating reduced the gas transmission rate, and ×ananassa Duch.). The vitroplants were acclimatized for two months coating application on the alkaline washed carambola had the lowest and then potted in plastic containers with substrate of vermicompost gas permeability. In conclusion: 1) the alkaline wash reconditioned the + sand + shell of rice in proportion 1:2:2 v/v. The plants were grown fruit surface, smoothing out cuticular microcracking, thus explaining in shed condition with range of temperature between 24 to 33 °C and 50% to 80% of relative humidity at 510 MSL. The treatments were the reduced transmission of CO2 O2 and water vapor in carambola

1168 HORTSCIENCE, VOL. 44(4), JULY 2009 four concentrations of gibberellic acid (0, 10, 20, and 40 mg·L-1), which Lenticel-related disorders in apple have been a concern for most where applied as sprays to the foliage of the plants in unique applica- growers and packers in Washington since the late 1990s. In a survey tion at the initial vegetative growth. The fruits were harvested between conducted in the 2005/06 storage season, we found that half of the January to May 2008 and the production was recorded, as well as, the packers contacted reported lenticel-related problems such as lenticel physical and chemical proprieties of fruit quality were determined. breakdown and lenticel blotch pit. The post harvest manifestation of The higher pick of production was in February for all the treatments; these disorders has resulted in signifcant losses—up to 30% of a stor- however the biggest fruits were harvested from April to May with the age room/orchard block/year. Cultivars most affected include Gala and largest values of fresh weight (6.1 g/fruit) for the doses of 10 mg·L-1 Fuji. Since 2006, the Washington Tree Fruit Research Commission with 22.9 and 20.00 mm of diameter polar and equatorial, respectively. has facilitated testing of promising approaches utilizing hydrophobic In relation to chemical quality, the total soluble solids (TSS) contents spray emulsions applied preharvest to mitigate lenticel breakdown. were between 3.21 to 3.44 °Brix and it were not affected by treat- Trials in commercial Washington orchards tested Raynox, soybean oil, ments. However, there was significant difference for pH (3.55–3.83), summer supreme oil, SylGard, SylTec, and EpiShield using different titratable acidity (TA) expressed by citric acid (0.71% to 0.94 %) and concentrations and timings. All fruit were harvested at commercial the relation TSS/TA (3.10–4. 22), but for these variables there was not maturity suitable for long term CA storage. We found no differences defined tendency for the specific gibberellic acid doses. The results for common maturity parameters at harvest or after storage between showed the different pick of production and variation for the physical control and treated fruit. Fruit from multiple sites expressed symptoms and chemical characteristics of the quality fruit during the period of after 3 and 6 months of CA storage similarly. No significant treatment evaluation and this could be due to the climatic conditions more than effect was seen regarding oil type or spray frequency. The 2008/09 effect of gibberellic acid treatments. trials are in storage and results will be discussed. It appears, lenticel Specified Source(s) of Funding: Universidad Centroccidental “Lisandro breakdown problems are best mitigated by harvest at optimum maturity Alvarado”, Lara State, Venezuela and careful postharvest handling. (104) Investigation of Factors Contributing to the (106) Laser Labeling, a Safe Technology to Label Development of Lenticel Break Down in ‘Royal Produce Gala’ Apples in South Africa Preeti Sood* Elmi Lotze* Lake Alfred; preeti.sood@ufl.edu University of Stellenbosch, Stellenbosch; [email protected] Ed Etxeberria K. Theron University of Florida, Lake Alfred, FL; [email protected]fl.edu University of Stellenbosch,, 7602 Matieland; [email protected] Jan Narciso USDA/ARS Citrus and Subtropical Products Lab, Winter Haven, FL; jan. Lenticel break (LB) down is a relatively new post harvest disorder [email protected] observed on apples in apple producing countries world wide. At present, Chris Ference the actual cause for this disorder is unknown, however there are several USDS/ARS, Winter Haven, FL; [email protected] factors that possibly contribute toward the observed increase in severity. Trials were conducted in commercial orchards in the Ceres area with Labeling of the produce has gained a marked attention in recent years. a history of LB to find possible reasons for the development for LB Laser labeling technology involves the etching of required informa- in ‘Royal Gala’. The possible influence of fruit calcium content and tion on the surface using low energy CO2 laser beam. The etching fruit maturity were investigated. Individual fruit analysis to determine forms alphanumerical characters by pinhole dot matrix depressions. whether mineral content influences susceptibility to LB could only be These openings can lead to water loss and provide an entry site for conducted in one season, but showed no correlation between fruit Ca pathogens. The present study was undertaken on citrus fruits (Citrus

content and LB. The effect of pre-harvest temperatures, rate of cool- reticulata and Citrus paradisi), tomato (Lycopersicum esculentum) POSTERS–Tuesday ing, and storage temperatures and amelioration of orchard conditions and pepper (Capsicum annum) focusing on water loss, peel appear- were assessed during the past two seasons. We did not find a simple ance and potential pathogen entry. The experiments measured water correlation between minimum or maximum daily temperatures before loss from etched areas and decay after exposing the etched areas to harvest and LB as was reported in Chile. We also investigated the effect the decay pathogens. There was no decay reported in and around the of vapor pressure deficit on the development of the disorder. Very little etched areas in citrus fruits while tomato and pepper had some decay. LB occurred at the experimental sites during 2006/7 and 2007/8. The Water loss was negligible in all the four cases, especially if waxed after storage trials were carried out, and even though statistical differences labeling.The amount of water loss in the selected fruits and vegetables from the storage results indicated a possible effect of cooling rate, no was different from each other. Label distortion was proportional with conclusive results were found due to the low incidence of LB in all RH and time of storage. trials during 2007 and 2008. Specified Source(s) of Funding: self (108) Proteomic Approach to Study Scald Disorder of Apples (105) Preharvest Programs to Reduce Lenticel Jun Song* Breakdown in Apples Agriculture and Agri-Food Canada, Kentville NS B4N 1J5, NS; Ines Hanrahan* [email protected] WTFRC, Wenatchee, WA; [email protected] QiFa Zheng Tory R. Schmidt Agriculture and Agri-Food Canada, Kentville NS B4N 1J5, NS; Washington Tree Fruit Research Commission, Wenatchee, WA; [email protected] [email protected] Gordon Braun James McFerson Agriculture and Agri-Food Canada, Kentville NS B4N 1J5, NS; Washington Tree Fruit Research Commission, Wenatchee, WA; mcferson [email protected] @treefruitresearch.com

HORTSCIENCE, VOL. 44(4), JULY 2009 1169 Charles Forney stored constantly at 20 °C until reaching ¼ orange stage, defined as Agriculture & Agri-Food Canada, Kentville, NS; Charles.Forney@agr. the point when between the fins showed a positive a-value. Aroma gc.ca volatiles were measured only on ripe fruit and via by headspace solid Christopher Watkins phase microextraction (SPME) fibers and gas chromatography-mass Cornell University, Ithaca, NY; [email protected] spectroscopy (GC/MS). Untreated fruit from either harvest maturity Eric Bevis had higher total volatiles when ripened constantly at 20 °C than when Agriculture and Agri-Food Canada, Kentville NS B4N 1J5, NS; stored at 5 °C for 14 d prior to transfer to 20 °C. Untreated fruit har- [email protected] vested at ¼ yellow or ½ yellow stage and stored at 5 °C had volatile production suppressed by 96% or 42%, respectively, compared to fruit Apple “scald” is a physiological disorder and still causing significant harvested at the same color stage and stored at 20 °C. The 1-pentanol economical loss of fruit industry. Despite for the extensive physiological was found in all of the 1-MCP-treated and non-treated fruit that were and biochemical studies, the mechanism of scald development is still stored at 20 °C. The 1-pentanol has green and grassy aroma notes and unknown. In this study, we applied 2-DE (2-dimensional electrophoresis) binds with other compounds during ripening to form esters that impart to separate the apple fruit peel proteins and stained with SYPRO Ruby. fruity aromas. For the fruit stored at 5 °C, 1-pentanol was found only in After gel analysis to identify up and down regulated spots, significantly the untreated fruit that was harvested at ½ yellow stage. The 1-octanol spots were excised from gels and identified with electrospray ioniza- was found in all of the samples except the fruit treated with 1-MCP and tion tandem mass spectrometry (ESI-MS/MS). “Red Delicious” fruit stored at 20 °C. The 1-octanol has a soapy aroma note and also binds were harvested before the climacteric stage, with internal ethylene with other compounds to form fruity esters. Beta ionone was the only concentration below 0.1-0.2 µl/L. After harvest, fruit were divided norisoprenoid compound found in the samples from this experiment into three groups, including control, DPA and 1-MCP treatment. DPA and was only found in fruit that were stored at 20 °C. Norisoprenoid (2000 μl/L) and 1-MCP (1.0 μl/L) were applied. Fruit were stored compounds are products of carotene degradation and have sweet and under cold air and CA (3.0 kPa +1.0 kPa CO ) at 0-1 °C for 4 and 6 2 honey aromas. Generally, the 1-MCP treatment suppressed total vola- months. Scald development was evaluated immediately after removal tile production, regardless of harvest maturity or storage temperature. from storage, or after an additional 7 days at 22 °C. A total of 900, 851, Fruit harvested at ¼ yellow, treated with 1-MCP, and stored at 5 °C and 954 spots have been visualized for the control, DPA and 1-MCP had poor appearance. 1-MCP suppressed volatile production for fruit treated fruits, respectively. Substantial quantitative and qualitative dif- stored at 20 °C, where fruit harvested at the ¼ and ½ yellow stages had ferences in protein profiles were shown. At day 0, there were 16, 28, total volatiles suppressed by 14% and 28%, respectively. Treatment and 29 proteins associated with the scald, DPA and 1-MCP treatments, with 1-MCP delayed days to ¼ orange stage by two to five days (at 20 respectively. Among them, three proteins were consistently present in °C temperature). Postharvest 1-MCP treatment could allow for a later fruit treated with DPA or 1-MCP. At day 7, 134 proteins were found to harvest, at ½ yellow stage when the fruit is sweeter. be specific to DPA treatment, while 71 proteins were common to both the DPA and 1-MCP treatments. LC/MS identification was conducted on day 0 samples, and 5, 17 and 17 proteins from control, DPA and 1-MCP respectively, were putatively identified and annotated. At this Crop Physiology/Physiology: stage of this study, we speculate that DPA and 1-MCP might have Environmental Stress their own unique function against scald, but may also share a common mechanism by protecting fruit tissue from oxidative stress damage Tuesday, 28 July 2009 12:00–12:45 pm caused by H2O2 and/or ROS. Identification of proteins related to scald development or to treatments inhibiting scald will give new insights to (71) Physiological Responses to Drought of Turfgrass understand the development of scald and further design the strategies to prevent this disorder. Species Under Field Conditions Nisa Leksungnoen* (109) Influence of Postharvest Aqueous 1- Utah State University, Logan, UT; [email protected] Methylcyclopropene (1-MCP) on the Aroma Paul G. Johnson Volatiles and Shelf Life of ‘Arkin’ Carambola Utah State University, Logan, UT; [email protected] Oren Warren Roger Kjelgren University of Florida, Gainesville, FL; owarren@ufl.edu Utah State University, Logan, UT; [email protected] Steven A. Sargent* Drought stress during summer is common in the Intermountain West, University of Florida, Gainesville, FL; sasa@ufl.edu but turfgrasses differ in how they respond to this stress. Poa pratensis Donald J. Huber L. (Kentucky bluegrass) quickly enters summer dormancy while tall University of Florida, Gainesville, FL; djhuber@ufl.edu fescue [Schedonorus phoenix (Scop.) Holub] remains green far longer. Jeffrey K. Brecht In order to understand the different drought tolerance or avoidance University of Florida, Gainesville, FL; jkbrecht@ufl.edu mechanisms, our objective was to study the physiological responses of KBG and TF under a prolonged drought.Two irrigation treatments were Anne Plotto applied in 2007 and 2008 to plots of ‘Newport’ and ‘Midnight’ Kentucky USDA–ARS SAA, Winter Haven, FL; [email protected] bluegrass and ‘Gazelle’ tall fescue in North Logan, UT. Each plot was 2 Elizabeth Baldwin × 1.5 m in size. Irrigation treatments were: 1) well-watered—irrigated USDA–ARS, Citrus & Subtropical Products Lab, Winter Haven, FL; liz. 3 times a week with 1.4 cm depth of water—and 2) plots that did not [email protected] receive irrigation. Measurements were made twice each week in 2007 Commercially produced ‘Arkin’ carambola was harvested at two ripe- and once each week in 2008 to document the plants’ response to the ness stages (¼ and ½ yellow). The following day fruit were treated by irrigation treatments. Stomatal conductance and surface temperature submerging in an aqueous 1-methylcyclopropene (1-MCP) solution were measured between 11 a.m. and 2 p.m. Predawn xylem water (200 ug·L-1 active ingredient) for 1 min and then air-dried. The fruit potential was measured with a pressure chamber. Soil water content were then stored at either 5 °C for 14 d and transferred to 20 °C or at 10-cm intervals to 100 cm was measured everyday in 2008. Ken-

1170 HORTSCIENCE, VOL. 44(4), JULY 2009 tucky bluegrass decreased in stomatal conductance and xylem water in growing plants under hypobaric (reduced atmospheric pressure) potential faster and greater than TF in response to dry conditions and conditions for extraterrestrial base or spaceflight environments. The was in complete summer dormancy within 5 weeks in both years. In objectives of this research were to determine the influence of hypo- contrast, most of TF leaves were green throughout the drought periods baria and reduced partial pressure of oxygen (pO2) [hypoxia] under in both years. This may be explained by the ability of TF to consume low and high light irradiance on carbon dioxide (CO2) assimilation water from the deepest soil profiles in the non-watered plots (80–100 (CA), dark-period respiration (DPR), and the CO2 compensation and cm depth) while KBG used most of the water to the 50–70 cm depths. CO2 saturation points of lettuce (Lactuca sativa L. cv. Buttercrunch). Stomatal conductance of KBG decreased sharply when it did not receive Plants were grown under variable total gas pressures [25 and 101 kPa water for 3 weeks while xylem water potential gradually dropped until (ambient)] at 6, 12 or 21 kPa pO2 (approximately the partial pressure 5 weeks in year 2007. However in 2008, the water potential was not in air at normal pressure). Light irradiance at canopy level of the low significantly different from the well-watered treatment until the sixth pressure plant growth system (LPPG) was at 240 (low) or 600 (high) week when values immediately dropped in KBG from –0.5 MPa to μmol·m-2·s-1. While hypobaria (25 kPa) had no effect on CA or the

–2.5 MPa and in TF from –0.3 MPa to –1.0 MPa. In late summer when CO2 compensation point, it reduced the DPR and the CO2 saturation plots were watered for recovery, KBG plots were mostly green within point, and increased the CA/DPR ratio. Hypoxia (6 kPa pO2) and low 3 weeks in both years. The surface temperature of grasses showed the light reduced CA, DPR and the CA/DPR ratio. Hypoxia decreased the same trend in both years where the well-water plots were cooler than CO2 compensation point. Hypoxia also decreased the CO2 saturation the non-irrigated plots and TF showed lower temperature than KBG point of ambient pressure plants, but had no effect on hypobaric plants. in both well-watered and no-watered plots. While low light reduced the CO2 saturation point, it increased the

CO2 compensation point, compared with high light plants. The results (72) Physiological Functions of Chilling Tolerant show that hypobaric conditions of 25 kPa do not adversely affect gas Sweetpotato (Ipomoea batatas L.) Genotypes exchange compared to ambient pressure plants, and may be advanta- Md. Shahidul Islam* geous during hypoxic stress. University of Arkansas at Pine Bluf, Pine Bluff, AR; [email protected] Specified Source(s) of Funding: NASA Ehiorobo Izekor University of Arkansas at Pine Bluf, Pine Bluff, AR; [email protected] (74) Changes in Concentrations of Free Amino Acids James O. Garner and Nonstructural Carbohydrates of Ligustrum University of Arkansas at Pine Bluf, Pine Bluff, AR; [email protected] japonicum as Plants Die from Water Stress An experiment was conducted in the greenhouse to select genotypes Dilma Silva* tolerant to chilling injury from lines of a genetically diverse population. University of Florida, Apopka, FL; dilma@ufl.edu

Seventy nine sweetpotato F1 breeding lines from three major variety Richard C. Beeson, Jr. crosses including ‘Vardaman’, ‘Jewel’, and MD-708’ were tested for University of Florida, Apopka, FL; rcbeeson@ufl.edu tolerance to chilling injury. Genotype differences in electrolyte leak- age, peroxidase activity and chlorophyll fluorescence yield following Ligustrum japonicum grown in 11.0-L containers were transplanted chilling exposure were found. No difference was found on for fatty acid into elevated cross-shaped rhizotrons using a commercial container percentage composition of the total glycolipid and phospholipids frac- substrate. After a short acclimatization phase, plants were subjected tion on the genotypes tested. Sixty percent total fatty acid in glycolipid to constant moisture levels of 30% of drained saturated capacity. fraction was C18:2 and C18:3. Fatty acid composition was not a factor Substrate moisture levels were maintained using capacitance probes, in chilling tolerant because it did not vary among the genotypes studied. which were relocated approximately every three weeks to the edge of Differences in leaf anatomy composition were also found among the the actively growing root tips. Over the course of four months, half the genotypes tested. However, since there were no differences in dif- plants died. During this period, both roots and shoot tips were sampled fusive resistance and transpiration rate among the genotypes, stomata and assayed for free amino acids and nonstructural carbohydrates. POSTERS–Tuesday density did not affect chilling tolerance through water loss. However, Comparison of these compounds between surviving and dying plants leaf shrinkage differences were found, which indicated differences in will be discussed. water loss. Leaf shrinkage, stomata density, diffusive resistance and (75) Water Stress on Physiological and Biochemical transpiration rate may interact with leaf water content and specific leaf weight with respect to leaf water loss under chilling conditions. The Traits of Hybrid Liriodendron Clones results indicated a lower volume of water per unit leaf area. Therefore Qirui Wang these genotypes should exhibit more injury (leaf shrinkage) with an Henan Academy of Forestry, Zhengzhou; [email protected] equal amount of water loss. It was concluded that leaf structure and Wei Fan physiological functions could have a role in chilling tolerance and were Henan Academy of Forestry, Zhengzhou; [email protected] different among the genotypes tested. Xiaofeng Tan Central South University of Forestry and Technology, Hunan 410004; (73) Hypobaria, Hypoxia, and Light Affect [email protected] Gas Exchange and the CO2 Compensation and Lin Zhang Saturation Points of Lettuce (Lactuca sativa) Central South University of Forestry and Technology, Huann 410004; Chuanjiu He [email protected] Texas A&M University, College Station, TX; [email protected] Deyi Yuan* Frederick Davies* Central South University of Forestry and Technology, Changsha; yuan- Texas A&M University, College Station, TX; [email protected] [email protected] Ronald E. Lacey Liriodendron chinense and L. tulipifera are popular plants for ornamen- Texas A&M University, College Station, TX; [email protected] tals and timber production. To better select and breed new Liriodendron varieties for drought tolerance, water stress of six F hybrid clones of There are important engineering and crop production advantages 1

HORTSCIENCE, VOL. 44(4), JULY 2009 1171 L. chinense × L. tulipifera (9911, 9901, 9907, 9906, 9902 and 9904) experiment was repeated during the growing season. After 120 days were conducted with their parents as the control. Potted seedlings at height, leaf area, and dry root weight were significant among treatments. their water holding capacity were placed in plastic house in mid-July Height increased linearly (P ≤ 0.001) from 231 mm under 0% shade and then different gradients of water stress were achieved under natural to 344 mm under 70% shade. Leaf area increased linearly (P ≤ 0.001) conditions. Leave samples were taken to determine their water content, from 178 cm² under 0% shade to 287 cm² under 70% shade. Treatments chlorophyll content, proline content and photosynthetic characteristics did not affect number of leaves, fresh or dry leaf weight, fresh or dry at 24 h, 72 h, 120 h, and 168 h after completed water saturation. The shoot weight, or fresh root weight. Dry root weight, however, decreased results showed that significant difference was present in decrease extent linearly (P ≤ 0.01) from 2.04 g under 0% shade to 1.40 g under 70% of leave water content under water stress between hybrid clones and shade. These results show that Osage orange can be exposed to higher their parents. The decrease extent in descending order was CKc, 9911, shade amounts without detriment to overall biomass, while increasing 9906, 9902, 9904, 9901, CKt, 9907. Water stress caused great damage height and leaf area. Therefore, Osage orange shows promise in an in- of chlorophyll in leaves of the two parents. The damage extent in all tercropping system without biomass being negatively affected, although Liriodendron samples was remarkably different, and in descending competition for water and nutrients also need to be considered. order was CKc, CKt, 9904, 9906, 9902, 9901, 9907, 9911. Chlorophyll content of different Liriodendron samples within 168h after water (77) Calla Lily Growth and Development in stress in descending order was 9911, 9901, 9907, 9906, 9902, 9904, Response to Saline Irrigation CKt, CKc. Water stress improved the proline content of Liriodendron. Maren Blohm* -1 The proline content of 9901 increased up to 360.0 mg·g FW, which Loyola College, Baltimore, MD; [email protected] equaled approximately three times the CKc. Water stress had great Lindsay Morningstar effects on photosynthetic characteristics of Liriodendron. With the Loyola College, Baltimore, MD; [email protected] increasing of water stress, net photosynthetic rate decreased sharply. The net photosynthetic rate of hybrid clones was much higher than that Salinity is an important factor impacting plant growth world-wide. of CKt and CKc. Evaluation on water tolerance of Liriodendron via Salinity is increasing not only in agricultural areas, but also in urban fuzzy decision method showed that 9901 and 9911 had the strongest areas, where ornamental plants are often grown; however, very little water tolerance capacity, followed by 9907, 9906, 9902, CKt, 9904 research has been done on salt stress and ornamentals. The purpose of and CKc in descending order, indicating that the hybrid clones of L. this research is to quantify the effect of moderate salt stress on Calla chinense × L. tulipifera generally exhibited remarkable super-parent Lily growth and developmental timing. Salt stress was measured in superiority in resistance to water stress. four different Calla Lily varieties (Flame, Pink Rehmanii, Pillow Talk, and White Alba) with three different concentrations of NaCl (0, 25, Specified Source(s) of Funding: the National “Eleventh Five-Year and 50 mM). In both the spring and the fall a group of rhizomes were Programme” of China (2006BAD03A0501) irrigated with saline irrigation solutions immediately after planting. (76) Impact of Shading on Seedling Growth of The time to emergence and time to first flower were recorded for 150 days. When the salt stress was applied pre-emergence there was no Maclura pomifera (Osage Orange) variation in emergence or flowering time in the fall. However, in the Jenna Rozum* spring the plants exposed to 50 mM NaCl had a lower percentage of Illinois State University, Normal, IL; [email protected] plants that flowered. Salt stress was also applied to a group of rhizomes David Kopsell after emergence for 63 days. Although there were differences among Illinois State University, Normal, IL; [email protected] varieties for height, biomass, and flower number there was no salinity Gary Bachman by variety interaction for any of the parameters measured. None of the Mississippi State University, Biloxi, MS; [email protected] salinity treatments had a significant effect on plant height, chlorophyll, or fresh weight. While flower number was not affected by salinity in Bryon Wiegand the fall, it was significantly decreased in the spring. The dry weight of University of Missouri, Columbia, MO; [email protected] the shoot was significantly decreased in the 50 mM treatment, which Osage orange (Maclura pomifera (Raf.) C.K. Schneid.) shows potential was correlated with decreased midday photosynthetic rates. Despite for use as a biofuel feedstock. Specifically, the fruit of Osage orange is the decrease in plant dry weight, the effect of salinity was so minimal being investigated for biofuel-production due to its high percentage of to overall appearance of the plants when the salt stress was applied oil, fermentable sugars, and other carbohydrates. Since Osage orange post-emergence that it was impossible to determine which plants were does not begin bearing fruit until approximately ten years of age, there being stressed just by visual inspection. It appears that there is tolerance is a need to evaluate the seedling stage of development. Because Osage to moderate salinities in these varieties of calla lily; therefore, irriga- orange is being considered for inclusion in intercropping production tion with lower quality water may be possible in both landscapes and systems, the effect of shading on seedling growth is important. How- greenhouse conditions without loss of ornamental quality. ever, there is limited data describing best management practices for seedling production. The objectives of our research were to determine (78) Water Relations, Yield and Fruit Quality of shade tolerance and the effects of varying shade percentages on Osage Grafted, Field-grown Watermelons orange seedlings in a controlled greenhouse environment. Greenhouse John L. Jifon* trials were conducted in January and June of 2008, lasting for 90 and Texas AgriLife Research at Weslaco, Weslaco, TX; [email protected] 120 days, respectively. Osage orange seedlings were grown in “cone- Kevin Crosby tainers” in each trial, sized 16 and 40 cubic inches, respectively, and Texas A&M University, College Station, TX; [email protected] set up in a randomized block design with four blocks. Treatments were a no shaded control, and shading cloth of 30%, 50%, and 70%. Plant Daniel Leskovar growth parameters including height, leaf number, fresh and dry leaf, Texas AgriLife Research, Horticulture,Texas A&M University, Uvalde, shoot and root weights, and leaf area were measured every 30 days TX; [email protected] during each trial. Trial one, which was conducted in January, resulted Vegetable grafting is becoming popular not only for disease control, in no significant differences among growth parameters, therefore the but also for managing abiotic stresses such as drought. The ability of

1172 HORTSCIENCE, VOL. 44(4), JULY 2009 suitable rootstocks to efficiently absorb soil moisture and maintain a favourable plant water status is critical in this role for grafting. In the Genetics/Germplasm/Plant Breeding: present study, we assessed whether the physiological responses of Fruit and Nut Crops grafted plants are consistent with predictions of a high capacity for water uptake by the rootstocks. Two commercial watermelon (Citrullus Tuesday, 28 July 2009 12:00–12:45 pm lanatus) cultivars (‘Summer Flavor 800’ and ‘Super Seedless 7167’) were grafted on hybrid squash (Cucurbita maxima × C. moschata) (283) Evaluation of Several Pecan Cultivars and rootstocks and grown on a sandy soil with a history of vine decline Selections as Immature Trees in Southern Georgia disease. Vine development during the vegetative growth stages was Patrick Conner* faster in grafted plants regardless of rootstock however, this develop- University of Georgia, Tifton, GA; [email protected] mental effect disappeared after canopy closure and fruit set. Grafted plants consistently had higher midday leaf water potentials, stomatal Eleven pecan (Carya illinoinensis) genotypes were evaluated over conductance and transpiration rates compared to non-grafted plants, seven years in a replicated test orchard located near Tifton,Ga. Geno- consistent with ample water supply from the root systems. In addition types included three USDA selections (USDA 85-1-2, USDA 86-3- to developing more crown side branches, canopy duration was much 32, USDA 86-3-666) six relatively new named cultivars (Cherryle, longer in grafted plants, allowing total yields to be greater than those Excel, Jenkins, McMillan, Nacono, Zinner) and two check cultivars of non-grafted plants. Average fruit soluble solids concentrations of (Desirable and Stuart). Actual yields were measured for each tree in grafted plants were higher than those of control non-grafted plants the test and a 50 nut sample was taken to determine nut quality. Trees but this effect was not consistent. The results are consistent with the were evaluated for leaf and nut scab (Fusicladium Effusum), black hypothesis that grafting commercial scions on rootstocks with vigorous aphid (Melanocallis caryaefoliae) damage, and sooty mold buildup on root systems can improve tolerance to drought and soil-borne diseases the leaves. Phenological traits measured included the dates of pollen through ample soil moisture uptake and maintenance of a favorable shed, stigma receptivity and shuck split. USDA 86-3-666 and USDA plant water status. 86-3-32 were judged to be unacceptable due to a combination of poor kernel quality and susceptibility to scab. ‘Jenkins’ was found to have (79) Novel Red, Green, Blue LED Light Source and unacceptable kernel quality in several years. ‘McMillan’ and ‘Excel’ Whole Plant Chamber Make Possible Photosynthetic appear to have potential for low spray situations where high levels of Assessment of Small Plants scab resistance can make up for lower nut quality traits. ‘Cherryle’ produced nuts of good quality, but yields have been low. ‘Nacono’ Patrick B. Morgan produced excellent quality nuts and had acceptable yields, but may be LI-COR Biosciences, Lincoln, NE; [email protected] too scab susceptible for this growing region. ‘Zinner’ produced good Jason R. Hupp* yields of excellent quality nuts and so far appears promising for this LI-COR Biosciences, Lincoln, NE; [email protected] growing region. Pecan trees are a long-lived crop and these cultivars Dayle K. McDermitt need to be evaluated for several more years to determine their perfor- LI-COR Biosciences, Lincoln, NE; [email protected] mance as mature trees. With increasing use of narrow-band LED lights in commercial horti- Specified Source(s) of Funding: Georgia Commodity Commission culture production systems, photosynthetic responses to spectral light for Pecan quality are increasingly important. Previously, photosynthetic studies of young or small, low-stature plants have been limited because small (284) Genetic Diversity and Classification of Malus leaves with short or no petioles are difficult to enclose within a tradi- Germplasm Using Simple Sequence Repeats (SSRs) tional clamp-style gas exchange chamber. Total plant CO2 flux can be Sarah M. Potts*

measured by enclosing entire container-grown plants within chambers. University of Illinois, Urbana, IL; [email protected] POSTERS–Tuesday However, the resulting net flux is the sum of the plant, growth media Mosbah M. Kushad and container fluxes. Isolation of only aboveground fluxes from low- University of Illinois, Urbana, IL; [email protected] stature plants is now possible with the new LI-COR 6400-17 Whole Schuyler S. Korban Plant Arabidopsis (WPA) Chamber. This chamber uses a novel flow University of Illinois, Urbana, IL; [email protected] path and blocking techniques to allow aboveground fluxes to be mea- sured independent of belowground gas exchange. Injections of 80 µg To assess genetic diversity and study genetic relatedness in a wide col- lection of Malus germplasm, microsatelites or simple sequence repeats CO2 (250 µL pure CO2) into the growth media just below the surface were suppressed by blocking and positive pressure (not detectable at (SSRs) were used to screen this collection. A total of 114 accessions 0.3 ppm resolution). With this chamber, fluxes can be measured from from the Malus core collection, maintained at the University of Illinois, low-stature and rosette plants as small as 1.5 cm2 total leaf area. The were evaluated for several phenotypic traits and genotyped using apple 6400-18 RGB (red, green, blue) LED light source, in conjunction with SSR markers. Data on several phenotypic traits were recorded, including this novel chamber, facilitates rapid assessments of photosynthetic fruit size, fruit weight, and fruit shape; moreover, data on several fruit capacity. The independently controlled red, green and blue LEDs can quality characteristics were also determined, including sugar content be used to measure photosynthetic efficiency at different wavebands (°Brix), titratable acidity (TA), and firmness. Each of the accessions was and intensities. Data will be presented demonstrating the use of the then genotyped using a single robust SSR marker from each of the 17 WPA and RGB to explore response of a small rosette froming species different linkage groups. These SSR markers were selected on the basis to spectral light quality. This chamber and light combination will allow of their high levels of polymorphisms, reproducibility, and their ampli- growth selection based on photosynthetic response assessment of small fication across wide genetic Malus backgrounds. Multiple alleles were plants or seedlings in a high throughput system. amplified across all screened accessions, thus allowing for analysis of genetic relatedness in this material. Phenotypic and genotypic data were Specified Source(s) of Funding: Private (Association, Foundation, used to characterize the genetic diversity in this material and to identify Industry) markers associated with some of the phenotypic traits analyzed. Specified Source(s) of Funding: Pioneer Hi-Bred International

HORTSCIENCE, VOL. 44(4), JULY 2009 1173 (285) Genetic Variability Among Eastern Black pear genotypes in their orchard based on our findings. Walnut Cultivars Specified Source(s) of Funding: This work was supported by the Key Michele R. Warmund* Project of State Forestry Administration (2006-12) and the Agricultural University of Missouri, Columbia, MO; [email protected] Achievement Transforming Programs of Science and Technology Mark Coggeshall Department (2008GB2D200219) University of Missouri, Columbia, MO; [email protected] (287) Pawpaw Cultivar Fingerprinting and Progeny Black walnuts (Juglans nigra L.) are valued for their uniquely fruity Determination Using Simple Sequence Repeat flavor and are often used as an ingredient in baked goods and ice cream, or are eaten as a snack food. Although black walnuts can be Markers harvested from wild trees, several cultivars have been selected for such Jeremiah Lowe* characteristics as ease of cracking, size of kernel, and thickness of Kentucky State University, Frankfort, KY; [email protected] husks and shells. Other characteristics, such as date of budbreak, time Shandeep Dutta of flowering, length of season and date of harvest, are also important Kentucky State University, Frankfort, KY; [email protected] adaptive traits as there is considerable variation within the species. The Li Lu University of Missouri Horticulture and Agroforestry Research Center Kentucky State University, Frankfort, KY; [email protected] (HARC) maintains a repository of more than 65 named cultivars of black walnut valued for their kernels. The identities of each of these Kirk Pomper cultivars have been confirmed by “fingerprinting”, using a series of Kentucky State University, Frankfort, KY; [email protected] ten single sequence repeat microsatellite markers. A subset of cultivars Sheri Crabtree maintained in the repository is used in an applied breeding program Kentucky State University, Frankfort, KY; [email protected] focusing on nut improvement. Average date of budbreak, flower type, Kyle Schneider bloom period, pollination date, nut season length, and harvest date of Kentucky State University, Frankfort, KY; [email protected] cultivars were collected from 2002 to 2006 at HARC in central Mis - The North American pawpaw [Asimina triloba (L.) Dunal] is a tree fruit souri. Photographic images of black walnut fruits were also obtained native to areas in the eastern United States and is in the early stages in 2007 as a visual aid for identification of confirmed cultivars and can of commercial production. Since 1994, Kentucky State University be accessed on a web site. (KSU) has served as the USDA National Clonal Germplasm Reposi- Specified Source(s) of Funding: ARS tory, or gene bank, for pawpaw; therefore, germplasm collection and assessment are research priorities. Not only would DNA fingerprinting (286) Pollen Tube Growth in Compatible and methods for pawpaw cultivars allow the authentication of clones cur- Incompatible Pear Genotypes rently being sold at nurseries, it would also allow the determination of the parentage of a number of advanced selections that are potentially Lin Zhang* the result of crosses attempted by the PawPaw foundation breeding Central South University of Forestry and Technology, Huann 410004; [email protected] effort. The objectives of this study were to develop simple sequence repeat (SSR) fingerprinting techniques with pawpaw cultivars and Xiaofeng Tan to determine if three advanced selections were truly progeny from a Central South University of Forestry and Technology, Hunan 410004; cross between the pawpaw selections 11-13 × 1-23. Leaf samples were [email protected] collected from the pawpaw selections Taytwo, Sweet Alice, NC-1, Donglin Zhang 11-13, 1-23, and three progeny of 11-13 × 1-23. Leaf samples were University of Maine, Orono, ME; [email protected] also collected from a cherimoya (Annona cherimola) tree in the KSU Deyi Yuan greenhouse; cherimoya is in the same family as pawpaw. DNA was Central South University of Forestry and Technology, Changsha; yuan- extracted from the leaves using the DNAMITE Plant Kit. Primers B3, [email protected] B103, B118, B129, and G119 were labeled with 6-FAM and used to Pollination compatibility between cultivars is essential for pear culti- amplify SSR products. These products were then separated using a vation, production and breeding programs. In recent years, many new 3130 Applied Biosystems capillary electrophoresis system. All prim- elite pear cultivars, such as ‘Cuiguan’, ‘Xizilv’, and ‘Lvbaoshi’, were ers failed to amplify products in cherimoya; however, products were bred in China. To provide functional data for further breeding work, amplified by the SSR primers in the pawpaw selections examined and we studied pollen tube growth in styles with fluorescence microscopy fingerprint patterns were useful in separating the genotypes. Unique allelic combinations using the primer set B103 indicated that two in two cross combinations ‘Cuiguan’ (S3S5) × ‘Lvbaoshi’ (S1S4) and advanced selections thought to be progeny of a cross between the ‘Xizilv’ (S1S4) × ‘Lvbaoshi’ (S1S4) in this work. The results showed that ‘Cuiguan’ × ‘Lvbaoshi’ was compatible and the other one was selections 11-13 × 1-23 are not actually the progeny from two parents. incompatible via observation on pollen tube growth in styles. Pollen Pollen contamination during hand pollination or pollinator activity grains in both cross combinations could germinate on the stigma, either before or after hand pollination resulted in seedlings that were while germination of pollen grains in incompatible pollination was not the result of a cross between 11-13 × 1-23. slower than that of compatible pollination. Pollen grains in incompat- Specified Source(s) of Funding: 1890 Institution Capacity Building ible pollination geminated on the surface of stigma in two hours after Grant pollination, whereas pollen tube stopped growth at the 1/3 location away from stigma after eight hours and the tip of which expanded (288) Assessment of Genetic Diversity of Pawpaw into sphericity. In contrast, pollen grains in compatible pollination geminated in one hour after pollination, and the pollen tube elongated (Asimina triloba) Cultivars with Simple Sequence to the middle parts of style after eight hours, entered ovary after 24 Repeat Markers hours, reached into embryo sac after 48 hours, and double fertilization Kirk Pomper* was finally completed after 72 hours. Growers could plant different Kentucky State University, Frankfort, KY; [email protected]

1174 HORTSCIENCE, VOL. 44(4), JULY 2009 Jeremiah Lowe ers evenly distributed throughout peach genome. All primer pairs Kentucky State University, Frankfort, KY; [email protected] produced amplification products in P. davidiana except for pchcms2. Li Lu Number of alleles observed ranged from 2 for CPPCT002 to 9 for Kentucky State University, Frankfort, KY; [email protected] UDP96-001 and UDP96-005, with average of 5.3. Allele frequency Sheri Crabtree per natural population ranged from 2.4 to 3.6 with average of 3.1. Kentucky State University, Frankfort, KY; [email protected] The size range of the amplification product varied from 50 to 500bp. Genetic diversity and population structure, as well as observed special Shandeep Dutta alleles and their distribution will be discussed. The obtained results Kentucky State University, Frankfort, KY; [email protected] should provide guidance for conservation and further utilization of P. Kyle Schneider davidiana germplasm. Kentucky State University, Frankfort, KY; [email protected] James Tidwell Specified Source(s) of Funding: USDA/CREES Project No. SC- Kentucky State University, Frankfort, KY; [email protected] 1700382 The pawpaw [Asimina triloba (L.) Dunal.] is a tree fruit native to the (290) Identification of the Chromosomal Genomic Southeastern and Midwestern United States which is in the beginning Regions Associated with Peach Tree Short Life stages of commercial production. In 1994, Kentucky State University Syndrome Using Microsatellite/SSR Markers (KSU) was designated as a satellite repository for Asimina preservation in the U.S. Department of Agriculture, National Plant Germplasm System. Xiaoyu Liu Germplasm evaluation, preservation, and dissemination have been a Clemson University, Clemson, SC; [email protected] high priority at KSU since that time. Cultivar loss since the beginning Gregory Reighard* of the early twentieth century may have eroded the genetic diversity Clemson University, Clemson, SC; [email protected] of commercially available selections. The objectives of this study were Ginger A. Swire-Clark to develop simple sequence repeat (SSR) primers for pawpaw and to Clemson University, Clemson, SC; [email protected] use SSR markers to assess genetic diversity in 41 pawpaw cultivars William C. Bridges and advanced selections from the PawPaw Foundation (PPF) breeding Clemson University, Clemson, SC; [email protected] program. Leaf samples were collected from the cultivars BH10, Cales Albert G. Abbott Creek, Davis, Gordon, Greenriver Belle, IXL, Middletown, Mitchell, Clemson University, Clemson, SC; [email protected] NC-1, Overleese, PA-Golden1, PA-Golden3, PA-Golden4, Potomac, Prolific, Rappahannock, Rebecca’s Gold, Shenandoah, Sue, Sunflower, William V. Baird Susquehanna, Sweet Alice, Taylor, Taytwo, Wabash, Wells, Wilson, Clemson University, Clemson, SC; [email protected] and Zimmerman, as well as 13 advanced selections from PPF. DNA Peach Tree Short Life (PTSL) is a complex disease syndrome involving was extracted from the leaves using the DNAMITE Plant Kit. Four nematodes, winter temperature, orchard history, pruning, Pseudomonas SSR primer sets B3, B103, B129, and G119 were labeled with FAM syringae and secondary pathogens. The disease occurs commonly in the and used to amplify SSR-PCR products. These products were then southeastern U.S., and possibly in other areas of the U.S., Europe, South separated using a 3130 Applied Biosystems capillary electrophoresis America and South Africa as the related Bacterial Canker Complex. system. Each primer yielded approximately 10 alleles for each primer PTSL causes premature tree death typically during the 2nd through 5th combination. Genetic relationships among the pawpaw cultivars and years after planting, resulting in large economic losses for growers. advanced selections showed significant genetic variation suggesting Recently, Guardian® BY520-9’ rootstock was selected for its tolerance that the genetic base of currently available cultivars is diverse. to PTSL; however, the genetic basis for this tolerance remains unknown. Nemaguard, a PTSL susceptible rootstock, and Guardian® selection Specified Source(s) of Funding: 1890 Institution Capacity Building

3-17-7 were crossed. Each F plant was selfed to create segregating F POSTERS–Tuesday Grant 1 2 populations. One hundred and seventy microsatellite/simple sequence (289) Assessing Genetic Diversity and Population repeat (SSR) markers, each uniquely mapped to chromosomal loca- Structure of Prunus davidiana from China Using tions on the Prunus reference genome, were used to screen the two parents and F -11. Forty-seven SSR markers showed polymorphism Simple Sequence Repeat (SSR) Markers 1 among the parents and were heterozygous in F1-11. Segregation data

Zhongping Cheng obtained from the F2-11 population for SSR marker inheritance and Clemson University, Clemson, SC; [email protected] their PTSL-response in a PTSL field trial were compiled to identify Ksenija Gasic* nuclear genomic regions associated with the response to PTSL. Of Clemson University, Clemson, SC; [email protected] the 47 polymorphic SSRs, nine (distributed on 4 linkage groups) were genetically linked with the response to PTSL through Analysis of Vari- Prunus davidiana, a wild species related to peach (Prunus persica L. ance (SAS). Identified SSR markers would be useful in marker-assisted Batsch), represents an important source of pest and disease resistance selection to facilitate selection of PTSL-tolerant rootstocks. Using in peach breeding programs. It is native to China, and in the Northern Joinmap® 3.0 software, a genetic map with seven linkage groups was China it is used as rootstock for peach and nectarine and as a core constructed from 30 of the 47 polymorphic markers with coverage of germplasm source of new traits for peach improvement. Distribution 217.5 cM. QTL analysis was conducted using PLABQTL1.2 software of P. davidiana in China has been investigated and several collecting by implementing the composite interval mapping method. QTLs were trips were organized during past few years, and tissue samples from detected from 0 to 10 cM from the upper terminus of linkage group 2 more than thirty accessions were collected from each natural population. in each of the five years evaluated. Two SSR markers located within Genetic variation and population structure of P. davidiana populations the QTL were also found to be associated with the response to PTSL was assessed using a set of microsatellite (SSR) markers selected by individual marker analysis. The upper region of linkage group 2 from Prunus reference map. A subset of 192 accessions representing appeared to be important because both the individual SSR analysis and seven populations collected from different environments from more the QTL analysis linked this region with the response to PTSL. The than four Chinese provincial areas were assayed using 20 SSR mark- genes controlling tolerance or susceptibility to PTSL may reside in this

HORTSCIENCE, VOL. 44(4), JULY 2009 1175 region. In the future, developing more SSR or other high-resolution markers to saturate this region will further define the specific region, Genetics/Germplasm/Plant Breeding: and ultimately identify the target genes. Ornamental Crops Tuesday, 28 July 2009 12:00–12:45 pm (291) Evaluation of Pyrus Germplasm for Resistance to Pear Psylla in the Orchard (302) Assessment of Ploidy Level and Genetic Richard Bell* Relationships Among Selected Hemerocallis Hybrids USDA–ARS - Appalachian Fruit Res Sta, Kearneysville, WV; richard. [email protected] Wagner A. Vendrame* University of Florida, Homestead, FL; vendrame@ufl.edu An orchard collection of 208 diverse Pyrus genotypes was evaluated by Luciana A. Fogaça both subjective ratings and objective counts of eggs and nymphs of pear Universidade Federal do Paraná, Curitiba; [email protected] psylla (Cacopsylla pyricola Föerster) to determine whether differences in susceptibility could be detected with a degree of reliability sufficient Ania Pinares for preliminary selection of germplasm. Subjective scores assigned in University of Florida, Homestead, FL; apinares@ufl.edu two consecutive years were highly correlated (r = 0.83), although the Francine L. Cuquel infestation was significantly more severe in the second year of the study. Universidade Federal do Paraná, Curitiba; [email protected] The correlation of subjective score with counts of eggs and nymphs was João C.B. Filho highly significant and moderately high (r = 0.64). Germplasm with P. Universidade Federal do Paraná, Curitiba; [email protected] pyrifolia or P. ussuriensis parentage were more resistant than those with The market for daylily hybrids (Hemerocallis) demands plants with P. communis parentage. Significant differences among genotypes could high quality, including diversity of colors, shape, size and number of be detected in egg counts in March and April, and in egg and 1st-3rd flowers. In Southern Brazil, a breeding program has been developed in instar counts in April. Significant differences among counts on fruit the city of Joinville, state of Santa Catarina focusing in the landscape spurs, vegetative spurs, and terminal buds or shoots were consistently market, aiming at plants with medium height and high number of found during all three months, with egg counts on fruit spurs higher flowers. Thirty crosses were performed among 13 daylilies cultivars during March and April. Counts of eggs and nymphs were generally selected for the plant characteristics mentioned above. However, some higher on terminal shoots in May. Significant variation among trees and crosses did not produce seeds or seed production was very low. We genotype by sample type interaction developed by May. Although the raised two hypotheses to explain such results; 1) the different ploidy sampling scheme used in this study could detect large differences in between the parents and 2) the genetic proximity of the parents due to host resistance, greater accuracy would require sample sizes too large the narrow genetic variability and consequently genetic inbreeding. To for practical use with large collections. verify these hypotheses, the present study aimed at examining the ploidy Specified Source(s) of Funding: USDA, ARS - Appropriated Project level and the genetic relationships among selected daylily hybrids using Funds chromosome and genetic analyses. Chromosome counting revealed a diploid chromosome number ranging from 20 to 24, with most cultivars showing ploidy of 22. This result indicates that ploidy level did not (292) A Navel Orange Variety Trial for the Desert affect seed formation. Genetic analysis was performed using RAPD Citrus Industry (Random Amplification of Polymorphic DNA) markers, whereby nine Glenn Wright* primers out of fifteen were screened and selected. From a total of 122 University of Arizona, Yuma, AZ; [email protected] bands obtained, 103 were polymorphic in at least one cultivar and 19 were monomorphic in all cultivars. The genetic similarity coefficient A navel orange (Citrus sinensis L. Osbeck) trial was established at the ranged from 0.35 to 0.65 and affected seed formation. The UPGMA University of Arizona Citrus Agriculture Center, Waddell, AZ in March cluster analysis showed cultivars grouping according to morphologi- 1999. This trial consists of the following selections: ‘Beck-Earli’, ‘Cara cal traits, such as flower shape and nectary gland color. These results Cara’, ‘Chislett’, ‘Fisher’, ‘Fukumoto’, ‘Lane Late’, ‘Powell’, ‘Spring’, demonstrated the existence of genetic proximity among cultivars. ‘Washington’, and ‘Zimmerman’, all on Carrizo citrange rootstock. ‘Washington’ is the standard cultivar selection for the local industry. (303) Analysis of Ploidy Levels in Dichroa febrifuga Yield, packout and fruit quality data have been collected since the first Sandra Reed* harvest in 2001. ‘Fisher’, ‘Lane Late’, ‘Beck-Earli’ and ‘Washington’ U.S. National Arboretum, McMinnville, TN; [email protected] have had the greatest 7-year cumulative yield, and those selections as Timothy Rinehart well as ‘Cara Cara’ had good annual yields in 2007-08. ‘Beck-Earli’, USDA–ARS, Poplarville, MS; [email protected] ‘Chislett’, and ‘Lane Late’ generally have had large fruit size over the course of the experiment. ‘Beck-Earli’ has had characteristically Dichroa febrifuga Lour. is an ornamental shrub that is a member of the elongated fruit, while the rest of the selections have had more rounded Hydrangeaceae. Molecular marker data have shown that this species is fruit. Among the early-harvest fruit, ‘Fisher’ is the least colored, and closely related to Hydrangea macrophylla (Thunb.) Ser. Fertile recip- ‘Fukumoto’ colors the best. Spring’ fruit has the best color among rocal hybrids between these two species have been produced, further those selections harvested late. ‘Cara Cara’ fruit typically has had the demonstrating their close relationship. When initial hybridizations highest level of solids, while the late navels have lower levels of solids. were made, only one D. febrifuga selection (GUIZ48) was available. Peel thickness and granulation of the selections varies depending on Chromosome counts demonstrated that this selection was a hexaploid the year. Based on the data collected so far, ‘Beck-Earli’, ‘Cara Cara’, with 108 somatic chromosomes. The objective of this study was to ‘Fisher’, ‘Fukumoto’, and ‘Lane Late’ appear to be suitable alternatives determine the ploidy level of additional D. febrifuga selections. Nuclear to ‘Washington’ in the desert. DNA amounts of seven D. febrifuga selections were estimated using flow cytometry. For each sample, at least 5000 DAPI-stained nuclei Specified Source(s) of Funding: Arizona Citrus Research Council were analyzed, revealing a single peak with a coefficient of variation (CV) less than 5%. Genome sizes were calculated as nuclear DNA

1176 HORTSCIENCE, VOL. 44(4), JULY 2009 content for unreduced tissue (2C) as: 2C DNA content of tissue = (mean of which are tetraploid (4x) with the genome composition AB. Selec- fluorescence value of sample ÷ mean fluorescence value of standard) tion of H. acetosella has led to the development of several cultivars × 2C DNA content of standard. Pisum sativum L. ‘Ctirad’, with a 2C including ‘Panama Red’ PPAF. These two species were hybridized content of 9.09 pg was used as the internal standard. Flow cytometric to develop ‘Panama Bronze’ PPAF. Response to these cultivars has measurements identified diploid, tetraploid and hexaploid D. febrifuga been positive, but a more compact habit is desirable. Therefore, re- selections. DNA content ranged from 6.1 to 7.2 pg among the three search was initiated to develop more compact forms through induced diploid selections (‘Chadwell’, ‘Yellow Wings’, an unnamed seedling polyploidization. Seed from crosses between H. acetosella and H. from Vietnam). Only one tetraploid selection (‘Yamaguchi Hardy’), with radiatus were germinated and treated with oryzalin at the cotyledon 12.6 pg DNA, was identified. Three selections (GUIZ 48, ‘Yamaguchi stage. As plants grew they were visually evaluated for signs typical Select’, an unnamed dwarf form) were found to be hexaploids with of induced polyploidy. Several plants were identified as potentially nuclear DNA amounts ranging from 17.0 to 17.4 pg. Identification of doubled and were further evaluated using flow cytometery. Three diploid and tetraploid cultivars will assist in efforts to transfer desirable plants were identified as polyploid, including one octoploid (8x) characteristics, such as evergreen foliage and persistent metallic blue and two cytochimeras (4x + 8x). The cytochimeras, also referred to berries, from D. febrifuga to H. macrophylla. as mixoploids, were further investigated in an attempt to determine which histogenic layer(s) were doubled. Stomatal measurements and (304) Polyploid Induction for Developing Sterile, flow cytometry of roots revealed the histogenic composition of the Non-invasive Forms of Nandina mixoploids to be 4-x-4 and 4-x-4+8, respectively. The mixoploids have Sarah M. Smith* yet to flower, preventing analysis of the LII. The octoploid (AABB) University of Florida, Wimauma, FL; smith04@ufl.edu exhibits a number of typical phenotypic effects of induced polyploidy such as thicker and darker leaves (RHS N186A), larger stomata, and Zhanao Deng shorter internodes. Field evaluation replicated in multiple locations University of Florida /IFAS, Wimauma, FL; zdeng@ufl.edu to determine plant height will be conducted in 2009. The octoploid Nandina domestica, a commonly used plant in the landscape, has exhibits greatly reduced fertility, likely due to increased frequency of invaded natural areas in several states in the southeastern United multivalents during gametogenesis. There has been no autonomous States, including Florida. Its invasiveness is primarily due to prolific seed set observed in the octoploid as seen in tetraploids. Also, there seed production and dispersal by animals through ingesting the berry. was low seed set obtained through controlled crosses with no germina- One approach to control the invasiveness of nandina is through ploidy tion to date, indicating that the octoploid may be functionally female manipulation and selection and use of sterile triploids. Ploidy analy- sterile. Controlled crosses are ongoing to determine levels of male and sis indicates that all available Nandina cultivars are diploids. The female fertility. The current research shows that oryzalin is effective at objective of this study was to induce tetraploids that can be used as inducing polyploidy in Hibiscus sect. Furcaria and represents the first parents in inter-ploidy pollination to produce sterile triploids. When time it has been used to induced polyploidy in the section. Furthermore, shoot tips were treated with colchicine in vivo, the percentage of new induced polyploids from hybrids of H. acetosella and H. radiatus growth containing polyploid cells varied between 0% and 80% among exhibit a more compact habit and reduced fertility, the latter being an several cultivars. The majority of the tetraploid cells were eliminated important trait for expanding the market to extreme southern regions during further growth of the shoots, and only a small percentage where it is perennial and could potentially become invasive. (<10%) of the shoots became stable tetraploids due to strong compe- tition between normal diploid and newly induced polyploid cells in (306) Analysis of Genetic Diversity and Identity of Nandina. To lessen diplontic selection and promote tetraploid cells Redbud (Cercis) Cultivars Using SSR Markers to develop into shoots, treated plants were monitored over time for Margaret Pooler* ploidy level and diploid growth were selectively removed regularly. USDA/ARS US National Arboretum, Washington, DC; margaret. When germinating seeds were used in colchicine treatment, 7% to [email protected] 24% of seedlings contained tetraploid cells, and a higher percentage POSTERS–Tuesday Timothy Rinehart (54%) of tetraploid-containing seedlings appeared to be stabilized. So USDA–ARS, Poplarville, MS; [email protected] far, a number of tetraploid shoots or seedlings have been obtained. They are being evaluated for possible changes in morphology. When Renee Arias coming into flowering, these tetraploids will be crossed with diploids USDA/ARS MSA Genomics Laboratory, Stoneville, MS; Renee. [email protected] to develop sterile triploid Nandina. Brian Scheffler Specified Source(s) of Funding: Southwest Florida Water Manage- USDA/ARS MSA Genomics Laboratory, Stoneville, MS; Brian. ment District Scheffl[email protected] Robert Trigiano (305) An Oryzalin Induced Polyploid from University of Tennessee, Knoxville, TN; [email protected] a Hybrid of Hibiscus acetosella × H. radiatus Redbud (Cercis spp.) are popular ornamental small trees or shrubs, (Malvaceae) Exhibits Reduced Fertility and valued commercially for their showy early spring bloom, heart-shaped glossy leaves, and adaptability to diverse environmental conditions. Altered Morphology The genus Cercis (Fabaceae) contains seven to thirteen species or sub- Ryan Contreras* species that occur in North America, Europe, and Asia. Species range University of Georgia, Tifton, GA; [email protected] in size from small shrubs to trees, tolerate full sun to shade, and are John Ruter hardy in USDA Zones 4–9. At least 12 cultivars of redbud have been University of Georgia, Tifton, GA; [email protected] introduced in the past decade with variations in foliage characteris- tics, flower color, or plant habit. We developed SSR markers for C. Hibiscus L. section Furcaria DC is a circumglobal group comprised canadensis and other species and used them to analyze 20 cultivars. of more than 100 species, many of which have potential for use as We also tested the inheritance of these markers by analyzing parents ornamentals primarily due to large showy flowers. Two species of and progeny from controlled hybridizations. These markers success- interest are H. radiatus Cav. and H. acetosella Welw. ex Hiern.; both

HORTSCIENCE, VOL. 44(4), JULY 2009 1177 fully differentiated among all the cultivars tested, and were useful rescence length, average flower rating, plant height, and plant width. in estimating genetic distances between cultivars. We are currently Flowering traits were measured weekly from the date of first flower investigating the relationship between genetic associations revealed until the date of first frost. Plant height and width were measured three by SSR markers and various horticultural and adaptability traits in times over the course of the study at 3, 19, and 33 weeks after plant- the landscape. ing. Pearson correlation coefficients between traits were estimated for all populations. Values for trait correlations were designated as (307) Analysis of Genetic Diversity and low (r ≤ 0.49), moderate (0.50 ≤ r ≤ 0.69), and high (r ≥ 0.70). Most Relationships in the China Rose Group trait correlations were low to moderate in both environments. Cor- Valerie A. Eitreim* relations between width measurements taken 19 weeks after planting Texas A&M University, College Station, TX; [email protected] and width measurements taken 33 weeks after planting were high and positive in both environments. Last flower date and total weeks David Byrne of flowering had high negative correlations in both environments. Texas A&M University, College Station, TX; [email protected] Total weeks of flowering and average inflorescence number had high Modern rose hybrids owe their origins in large part to traits inherited positive correlations in both environments. Average inflorescence from the China Roses, most notably, the everblooming character number and last flower date were highly negatively correlated in the (Shepherd, 1978). However, the wild origins, early breeding history, field with moderate negative correlation found in containers, while and diversity of the China Rose group, including R. chinensis and its correlation between total weeks flowering and flowering duration varieties, cultivars, and hybrids, is largely unknown. Twenty-three was highly positive in containers and moderately positive in the field. microsatellite markers were used to survey the genetic diversity and Though degree of correlation varied between the container and field relationships among the China Roses, their early hybrids, and select environments, significance and direction of correlation were similar species from sections Indicae and Synstylae. The utility of the inter- in both environments. Traits that show significant correlation may genic chloroplast spacer trnH-psbA in Rosa was also tested to obtain affect selection progress in Vitex. information on the maternal lineage of the China Roses. The SSR data clustered the rose accessions into groups, which in most cases (309) Cistus and Halimium Species and Cultivars agreed with the horticultural classification of the accessions (accord- Grow and Flower Well in Western Oregon ing to Modern Roses IX). The early Tea roses were the exception. Neil Bell* These fell into a large group along with roses classified as Hybrid OSU Extension, Salem, OR; [email protected] Chinas, Noisettes, Bourbons, and Polyanthas, all with either unknown James Altland parentage or a Tea rose(s) in the recorded parentage. One accession USDA–ARS, Wooster, OH; [email protected] of R. odorata var. gigantea from China was also included in the Tea cluster. The remainder of the roses from the China, Noisette, and Ninety-three species, cultivars, and hybrid selections of Cistus spp., Bourbon classes formed separate clusters, while the remainder of the Halimium spp. and × Halimiocistus were evaluated for growth, flower- Polyantha roses clustered with accessions of R. multiflora, one of the ing, landscape quality, and cold hardiness in Aurora, OR, from 2004-07. parent species of that hybrid class. The results also support, or disagree The evaluation site was a south-sloping 0.2 ha plot in full sun at the with, the recorded parentage or ‘sport’ status listed for a number of the OSU North Willamette Research and Extension Center. Plants were cultivars, and give identity to several ‘found’ roses being grown under spaced 1.5 m apart within rows and rows were spaced 3 m apart in a new names. Preliminary results from the chloroplast spacer sequence randomized, replicated design. Plants were watered by hand at plant- show 100% amplification and good variability, which should prove ing in May 2004 and received periodic overhead irrigation through useful for tracing maternal lineages. Aug. 2004, after which no irrigation was applied for the duration of the study. Plants were not fertilized or pruned during the evaluation. (308) Quantitative Trait Correlations in With the exception of ‘Enigma’, all plants of which died in 2004, all a Vitex Breeding Program cultivars grew well through 2007. Growth habit varied greatly among Amanda Hershberger* the cultivars, from low, spreading plants such as Halimium calycinum University of Georgia, Athens, GA; [email protected] and Cistus creticus ‘Lasithi’ to taller, rounded shrubs like C. ‘Snow Fire’ or C. ‘Ann Baker’ and upright shrubs like C. ×aguilarii and C. David Knauft ×verguinii. Flowering commenced in mid-April with H. calycinum University of Georgia, Athens, GA; [email protected] and H. umbellatum, but the majority of cultivars flowered from early Carol Robacker May through mid-June, and a few cultivars continued to flower well University of Georgia, Athens, GA; [email protected] into July. The length of the flowering period varied significantly from Breeders generally attempt to improve a number of traits simultane- several days to several weeks. Striking differences in plant quality ously. If these traits are positively correlated, the response to selection became apparent as plants matured. Some cultivars, such as Gordon will be more rapid than for characteristics selected separately. Trait Cooper and Snow Fire, retained good foliage quality and plant habit, incorporation may even be delayed for many generations if several while other cultivars such as Victor Reiter and Silver Pink declined important traits are negatively correlated. Furthermore, environmental in appearance and became sparsely foliated. Cold injury was gener- differences can alter trait correlations, so evaluating traits and calculat- ally moderate during the evaluation period, with most damage being ing correlations in more than one environment may be a useful aid in limited to foliage or modest stem dieback. The plants showing the selection. The objectives of this study were to assess trait correlations most cold damage were Cistus creticus ‘Tania Compton’, C. ×pau- in two environments to determine whether each trait is independent ranthus and Halimium atriplicifolium. Several cultivars are suggested of the other traits, and whether trait correlations will be the same in for landscape use as dwarf groundcovers including C. ‘Grayswood each environment. Segregating populations of Vitex and their parents Pink’, C. ×gardianus, and H. lasianthum. More vigorous plants that were cloned and grown in containers or in the field. Traits evaluated function effectively as taller groundcovers include C. ×laxus and C. included Cercospora leaf spot resistance, first flower date, last flower ×obtusifolius. date, flowering duration (time from date of first flower to last flower), Specified Source(s) of Funding: Agricultural Research Foundation total weeks of flowering, average inflorescence number, average inflo-

1178 HORTSCIENCE, VOL. 44(4), JULY 2009 system use will be evaluated by users during and following database Genetics/Germplasm/Plant Breeding: implementation. Vegetable Crops and Cross-Commodity 2 (334) Genetic and Phenotypic Diversity within Tuesday, 28 July 2009 12:00–12:45 pm the USDA, ARS Capsicum baccatum Germplasm Collection (333) GRIN-Global: An International Project to Elena Albrecht Develop a Global Plant Genebank and Information KeyGene N. V., Wageningen; [email protected] Management System Dick Lensink G. Kinard* KeyGene N. V., Wageningen; [email protected] USDA–ARS-NGRL, Beltsville, MD; [email protected] Robert Saftner P. Cyr USDA–ARS, Food Quality Lab, Beltsville, MD; [email protected]. USDA–ARS-PIRU-NCRPIS, Ames, IA; [email protected] gov B. Weaver John Stommel* Bioversity International, Ames, IA; [email protected] USDA–ARS, Beltsville, MD; [email protected] M. Millard The genus, Capsicum, is native to the tropics of Central and South USDA–ARS-PIRU-NCRPIS, Ames, IA; [email protected] America. C. annuum is the most widely cultivated and economically C. Gardner important Capsicum species today. Four additional domesticated USDA–ARS-PIRU-NCRPIS, Ames, IA; [email protected] Capsicum species include C. frutescens, C. chinense, C. baccatum, and C. pubescens. Approximately 25 additional wild Capsicum spe- M. Bohning cies are recognized but lack extensive study on their biology. Utilizing USDA–ARS-NGRL, Beltsville, MD; [email protected] morphological, chemical, and sensory analysis and molecular markers, G. Emberland we have assessed intraspecific variation within 250 C. baccatum acces- USDA–ARS-NGRL, Beltsville, MD; [email protected] sions obtained from the USDA, ARS, PGRCU. A smaller number of Q. Sinnott C. annuum, C. chinense, and C. frutescens accessions were similarly USDA–ARS-NGRL, Beltsville, MD; [email protected] evaluated. Domesticated types of C. baccatum are designated as C. J. Postman baccatum var. pendulum and wild forms as C. baccatum var. baccatum. USDA–ARS-NCGR, Corvallis, OR; [email protected] C. baccatum var. pendulum is widely distributed in Central and South K. Hummer America whereas the wild form, C. baccatum, is centered in Bolivia and USDA–ARS-NCGR, Corvallis, OR; [email protected] surrounding areas. Similar to a number of other Capsicum species, C. T. Franco baccatum pod types are diverse and fruit size, pigmentation, and flavor Bioversity International, Cali; [email protected] attributes exhibited considerable variability. Fruit size ranged from very small round fruit (0.5 cm diameter) typical of C. baccatum var. M. Mackay baccatum to tapered elongate (12–15 cm length) fruit for C. baccatum Bioversity International, Rome; [email protected] var. pendulum. Mature fruit pigmentation varied from yellow to orange L. Guarino to red. Fruit flavor varied from mild to very pungent with presence or Global Crop Diversity Trust, Rome; [email protected] absence of unique aromatics and flavors. Principle components analysis P. Bretting based upon marker diversity identified two major clusters contain- USDA–ARS-NPS, Beltsville, MD; [email protected] ing C. baccatum var. pendulum and four smaller, additional clusters.

The mission of the GRIN-Global Project is to create a new, scalable The latter consisted of a single cluster containing the majority of the POSTERS–Tuesday version of the Germplasm Resource Information System (GRIN) to C. baccatum var. baccatum accessions and three additional clusters provide the world’s crop genebanks with a powerful, flexible, easy- represented by both forms of the species. A tendency for clustering of to-use plant genetic resource (PGR) information management system. accessions based upon their geographic origin was evident. The results The system will help safeguard PGR and information vital to global of the genetic diversity analysis will be discussed in relation to fruit food security, and encourage PGR use. Developed jointly by the USDA phenotype attributes. Agricultural Research Service, Bioversity International and the Global (335) Politics and Promiscuity in Vegetable Seed Crop Diversity Trust, GRIN-Global will be deployed in selected plant genebanks worldwide in 2011. The .NET Framework and Visual Studio Production: The Unintended Consequences of Going development environment were chosen for the project. A core set of web Green services, enterprise services or other technologies will update data stored Michael Quinn* locally or on networks, distribute centralized data to off-site systems, Oregon State University, Corvallis, OR; michael. and enable third party data sharing. The database and interface(s) will [email protected] accommodate commercial and open-source programming tools, be Carol Malllory-Smith database-flexible (MySQL, MS SQL Server, Oracle), and require no Oregon State University, Corvallis, OR; carol.mallory- licensing fees. The database will be deployable on stand-alone computers [email protected] or networked systems. Iterative programming strategies will support James R. Myers continuous product evaluation and refinement; advanced prototypes Oregon State University Vegetable Breeding Program, Corvallis, will be extensively beta-tested. Bioversity International will deploy OR; [email protected] GRIN-Global internationally, working cooperatively to document the new system in Arabic, English, French, Russian, and Spanish, translate In Oregon’s Willamette Valley, vegetable seed production is estimated its interface, and implement it in developing countries. Implementation to be a 27 million dollar a year industry. Except under special permit will be monitored and barriers to adoption identified. The impact of from the Oregon Department of Agriculture, canola can only be grown

HORTSCIENCE, VOL. 44(4), JULY 2009 1179 in the Willamette Valley as a small scale seed crop, with larger acreage (337) Inheritance of Resistance to Zucchini Yellow fields being relegated to specific rapeseed control districts outside of Mosaic Virus in Tropical Pumpkin the valley. The combination of the need for rotational crops with grass seed production, and an increased desire for local biofuel production Luis G. Sierra-Rivera* has created interest among growers to plant Brassica napus (canola) University of Puerto Rico, Mayaguez, PR; [email protected] inside the valley. However, serious questions have arisen over the Linda Wessel-Beaver potential damage large scale canola production could have on the pre- University of Puerto Rico, Mayaguez, PR; [email protected] existing Brassica vegetable seed production. To address these concerns Giseiry Rosa-Valentín we developed two specific objectives: 1) Determine the potential of University of Puerto Rico, Mayaguez, PR; [email protected] gene flow and hybridization via pollen flow from B. napus to related José Carlos V. Rodrigues Brassica vegetable crops; and 2) Evaluate whether transgenes from B. University of Puerto Rico, Río Piedras, PR; [email protected] napus will be detectable in viable and non-viable outcrossed Brassica vegetable seed. In-field crossing experiments were conducted in 2007 In Cucurbita moschata Duchesne (tropical pumpkin; butternut squash) and 2008 using receptor plants placed within a conventional (non the landrace ‘Nigerian Local’ (NL) has been identified as having re- GMO) B. napus field. In each year, two independent crossing experi- sistance to Zucchini yellow mosaic virus (ZYMV). Previous studies ments, one using a self incompatible Brassica rapa var. chinensis, and indicate that resistance from NL is completely dominant. Our experience a second using cytoplasmic male sterile (CMS) Brassica oleracea var. during a backcrossing program to incorporate resistance from NL into italica line were arranged in a 15 × 15 m block within the field. Once the local cultivars Taina Dorada (TD), Soler (SOL) and Verde Luz (VL) siliques had set on the receptor plants, each species was returned to the suggests that inheritance of ZYMV resistance is more complex than a greenhouse and harvested individually. Results of the flow cytometry single dominant gene. The resistant parent NL, three susceptible parents analysis conducted on the progeny indicate that hybridization does (TD, SOL, VL), the F1 between NL and each susceptible parent, and F2 occur between B. rapa var. chinensis and B. napus, 23% in 2007 and populations of NL × VL and SOL × NL were planted in the greenhouse 11% in 2008. However, all seed that were produced on the B. oleracea and mechanically inoculated with a local, molecularly characterized var. italica were shriveled and failed to germinate. Greenhouse crosses ZYMV isolate. Readings were taken thru 17 days post-inoculation when th were conducted using transgenic (RoundUp Ready) B. napus and several the 4 true leaf was submitted to DAS-ELISA. In a follow-up study, ad- cultivars of the previously mentioned vegetable species with blow flies ditional parental and F1 plants were inoculated, evaluated for symptoms (Diptera:Calliphoridae) as pollinators in enclosed cages. Results of these and tested with ELISA. Inoculated plants of NL were completely free experiments indicate that outcrossing rates varied greatly (0.0026% to of symptoms. All susceptible parents showed mild to severe symptoms. 15%) depending on B. rapa var. chinensis cultivar, and transgenes were All F1 plants showed clear, albeit very mild, symptoms (usually streaks) st nd rd detectable in both germinable and non-germinable seed produced on on the 1 and 2 true leaf (occasionally the 3 ). ELISA readings were non-transgenic B. rapa female plants. Neither viable seed, nor transgenes slightly elevated compared to NL (whose readings were similar to the were detected in any of B. oleracea greenhouse crosses. negative control). A follow-up study with parents and F1 plants gave similar results, indicating that the resistance from NL is incomplete. The Specified Source(s) of Funding: USDA-BRAG two F2 populations showed a continuous range of symptoms, making classification into a “resistant” and “susceptible” category difficult, (336) Genetic Control of Floral Morph in Tristylous and classification into an “intermediate” category nearly impossible. Pickerelweed (Pontederia cordata L.) ELISA readings did little to aid in classification. When plants with mild Lyn Gettys* symptoms on the first or second leaf were classified as “resistant” and University of Florida, Gainesville, FL; lgettys@ufl.edu all others as “susceptible”, the two populations segregated 3 resistant: D.S. Wofford 1 susceptible. However, only 1 of 24 resistant plants of (NL × VL) F2 University of Florida, Gainesville, FL; [email protected] was completely free of symptoms, while 13 of 26 resistant plants of (SOL × NL) F2 were symptomless. This suggests that additional genes Pickerelweed (Pontederia cordata L.) is a diploid (2n = 2x = 16) for resistance are involved and that SOL may carry an additional gene tristylous wetland perennial native to Florida. Populations usually or genes for resistance that are not found in VL. We have observed comprise three floral morphs that differ reciprocally in style length and that many backcross-derived F3 families originating from seedlings anther height. All flowers are perfect and bear a single style and two identified as resistant in the BC:F2 are completely susceptible rather sets of three anthers in one of three positions (long, mid and short). than either segregating for resistance or being completely resistant, as Plants bearing flowers with a style in the long position are referred to would be expected with a monogenic completely dominant resistance. as L-morphs, while plants that produce flowers with a style in the mid Nevertheless, we have been able to identify some lines that show both or short position are called M- and S-morphs, respectively. This floral horticultural promise and ZYMV resistance. polymorphism promotes disassortative mating among the three floral morphs. The goal of this study was to determine the number of loci, Specified Source(s) of Funding: USDA-CSREES-HSI; USDA-CS- number of alleles and gene action controlling floral morph in picker- REES-TSTAR elweed. Three parental lines (one each of the L-, M- and S-morph) (338) Quantifying Vitamin C and Flavonoid Levels were used to generate S and F populations. The F populations were 1 1 2 in a Unique F Pepper Family produced through self-pollination of F1 plants. Progeny ratios of S1, F1, 2 and F2 generations revealed that tristyly is controlled by two diallelic Justin D. Butcher* loci (S and M) with dominant gene action and expression is influenced Texas A&M University, College Station, TX; [email protected] by epistasis. The S locus is epistatic to the M locus, with the S-morph Kevin Crosby produced by plants with the dominant S allele (genotype S _ _ _). Plants Texas A&M University, College Station, TX; [email protected] with recessive alleles at the S locus were either L-morph (ssmm) or Kilsun Yoo M-morph (ssM_). The results of this experiment demonstrate that the Texas A&M University, College Station, TX; [email protected] inheritance of tristyly in pickerelweed is the same as previously reported for several tristylous species in the Lythraceae and Oxalidaceae. Peppers (Capsicum spp.) are a diverse group of economically important plants that have gained attention for containing various phytochemicals

1180 HORTSCIENCE, VOL. 44(4), JULY 2009 in their fruit tissue; some of these phytochemicals have beneficial effects (340) Field and In Vitro Studies of Jerusalem on the health of people who consume them on a regular basis. Laboratory Artichoke (Helianthus tuberosus L.) and Its Potential analysis has confirmed pepper fruit contains carotenoids, polyphenolics, capsaicinoids, flavonoids, and various vitamins (Howard et al., 2000). as Biofuel Feedstock Of these, vitamin C (ascorbic acid) and flavonoids (quercetin and lu- Sukhwinder Aulakh* teolin) are currently being targeted for genetic improvement. As more Institute for Advanced Learning and Research(IALR), Danville, VA; people learn of the importance a healthy diet can play in the longevity [email protected] of their life, development of fruits and vegetables with elevated levels Richard Veilleux of these different compounds will progress. Previously, our extensive VPI & SU (Virginia Tech), Blacksburg, VA; [email protected] screening for flavonoid levels in diverse pepper germplasm identified Muhammad J. Iqbal extremely high concentrations of quercetin and luteolin in line CA377. Institute for Advanced Learning and Research(IALR), Danville, VA; In March 2008, we planted approximately 150 F2 progeny of the cross [email protected] CA377 × B22, at the Texas AgriLife research station in Uvalde, TX. Helianthus tuberosus Plants were grown with commercial practices, and fully mature fruit Jerusalem artichoke ( L.) is a perennial native were harvested and transported to College Station, TX. Peppers were North American, plant species related to sunflower. To many of us, it is known as a weed. It has been used as human food, animal feed, held at –80 °C until they were analyzed at the analytical core unit of source of inulin and ethanol and as raw material for large number of the Vegetable and Fruit Improvement Center. 3% meta-phosphoric acid other industrial purposes. In the present study, twenty two accessions and 100% methanol were the solvents used to extract vitamin C and obtained from USDA germplasm collection were evaluated in a rep flavonoids respectively. At the end of the preparation process, each - sample was inserted into a High-Performance Liquid Chromatography licated Randomised Block Design (RBD) experiment, at the Agricul- (HPLC) machine to complete the analysis. An alpha bond amino 10μm ture Farm of Virginia Tech, Blacksburg, VA during cropping season isocratic column (254 nm, 0.8 ml/min., 10 min.) and a Nova-pak C-18 2008. Plant growth characters related to biomass production were evaluated in this preliminary study. Significant variation was found in 4 μm isocratic column (0.5% H PO , 360 nm, 1 ml/min, 20 min.) were 3 4 plant height (ranging from 105 cm in PI 451980 to 191 cm in Ames used for vitamin C and flavonoids, respectively. Vitamin C levels varied 18010), internodal length range from 3.38 cm to 7.83 cm, number of between 500 and 2,000 μg/g while total flavonoid levels varied from branches (ranging from 28 to 47) and other character studied. Disease 85 to 500 μg/mL. DNA was also extracted from leaf tissue of each F 2 reactions of these lines to powdery mildew (Erysiphe cichoracearum progeny plant. This data is currently being utilized to screen DNA bulks DC) and rust (Puccinia helianthi) were accessed under natural field from high and low progeny as well as both parents to identify polymor- conditions. An in vitro regeneration protocol was also developed using phic RAPD markers. Reproducible candidate markers will be utilized to screen all progeny to confirm linkage to major QTL contributing PI547233 accession, which can accelerate crop improvement efforts using recombinant DNA techniques. Based on its growth potential and to elevated levels of vitamin C and flavonoids. The goal is to enhance large amount of variation present in H. tuberosus germplasm it can be marker assisted selection for relevant fruit quality genes. considered as a good candidate for biofuel feedstock. Specified Source(s) of Funding: Adviser Specified Source(s) of Funding: Institute for Advanced Learning and (339) Phytophthora Foliar Blight Multi-race Research (IALR), Commonwealth of Virginia and USDA appropria- Screening Technique in Capsicum annuum L. tions Ariadna Monroy-Barbosa* New Mexico State University, Mesilla, NM; [email protected] Paul W. Bosland Horticultural Crops Culture and Management: New Mexico State University, Mesilla, NM; [email protected]

Herbs, Spices and Medicinal Plants POSTERS–Tuesday Phytophthora blight is a major disease threat to production and long- Tuesday, 28 July 2009 12:00–12:45 pm term viability of chile pepper (Capsicum annuum L. ), caused by the oomycete Phytophthora capsici. Separate and independent resistant genetic systems for root rot, foliar blight, and stem blight syndromes (155) Podophyllotoxin Concentration in Needles of have evolved for each disease syndrome (Sy et al., 2005). In addition, Juniperus virginiana L. Collected from Mississippi to several races of the pathogen have been identified (xxxx, ssss). Therefore, North Dakota a reliable and accurate screening technique to detect resistance to each race for foliar blight would be helpful. A new technique is described Valtcho D. Zheljazkov* that allows for multiple races to be evaluated on a single plant. The Mississippi State University, Verona, MS; [email protected] P. capsici resistant line Criollo de Morelos (CM-334), the susceptible Charles Cantrell lines Jalapeno Espinalteco (NMCA10399), Camelot; and three New USDA–ARS, Natural Products Utilization Research Unit, Univer- Mexico Recombinant Inbred Lines (NMRILs), were used to evaluate sity, MS; [email protected] a new technique for Phytophthora blight multi-race screening. Three Valtcho Jeliazkov different P. capsici races were used. The resistant control CM-334 Mississippi State University, Verona, MS; [email protected] was always resistant, and the susceptible controls (NMCA10399 and Eastern red cedar (Juniperus virginiana L.) is a perennial woody plant Camelot) were always susceptible against the races tested. The NMRILs with a wide ecological adaptation and numerous industrial uses. Red displayed race-specific resistance against the different races, as they cedar lumber wastes (but not red cedar leaf biomass) have been utilized did with single inoculations. This technique is reliable and accurate for production of juniper essential oil. Previous research has shown in evaluating the foliar blight disease syndrome using different races that the eastern red cedar leaf biomass contains podophyllotoxin, an simultaneously on a given plant. anticancer compound and the precursor of semi-synthetic drugs used Specified Source(s) of Funding: New Mexico State University in chemotherapy; etoposide, teniposide and ethopophos. Currently, podophyllotoxin is commercially obtained from Indian mayapple

HORTSCIENCE, VOL. 44(4), JULY 2009 1181 (Podophyllum emodii Wall.) However, prior research demonstrated from this study that ginger can be grown not only as a medicinal and that eastern red cedar may be a good alternative as a source for podo- horticultural crop, but also as a crop with high ability to phytoremedi- phyllotoxin. The objective of this study was to establish the limits ate P, N, and Cu from the Delmarva soil which is known for its high of variations of podophyllotoxin concentration in Eastern red cedar contents of these elements. in the USA and identify desirable genotypes. In 2008, forty six sites were sampled in Mississippi, Alabama, Tennessee, and North Dakota. (157) Plant Part and Extraction Temperature All samples contained podophyllotoxin; its concentration varied from Affect Cilantro (Coriandrum sativum) Biomarker 0.017% to 0.42% on a dry matter basis. It was concluded that Eastern Compounds red cedar could be used as a sustainable source for podophyllotoxin. Damayanthi (Dayan) Ranwala* We are continuing the work to select high-podophyllotoxin genotypes, Clemson University, Charleston, SC; [email protected] which could be developed as cultivars for commercial production of podophyllotoxin. Richard L. Hassell Clemson University, Charleston, SC; [email protected] Specified Source(s) of Funding: Mississippi State University Specialty Robert J. Dufault Crops Project Clemson University, Charleston, SC; bdfl[email protected] (156) Effect of Poultry Compost Applications on Joseph D. Gangemi Ginger Growth and Phosphorous Phytoremediation Clemson University, Charleston, SC; [email protected] Instar Eljak* This study was conducted to evaluate the influence of plant parts University of Maryland Eastern Shore, Princess Anne, MD; (flowering tops and basal leaves) and two extraction temperatures

[email protected] (60 °C vs. 90 °C) on total phenols (TP) and flavonoids (TF) contents, and a main biomarker compound in cilantro, quercetin. Cilantro (cv. Lurline E. Marsh Slow Bolt) was grown as a fall/winter crop in Charleston, SC. Four University of Maryland Eastern Shore, Princess Anne, MD; replicates, each replicate from at least 10 plants, were sampled in late [email protected] October and separated into floral parts and basal leaves and kept at 0 Corrie P. Cotton °C. After 3 months of storage, all plant materials were air-dried at 32 University of Maryland Eastern Shore, Princess Anne, MD; °C for 4 days and ground to a powder. Each replicate powder was acid [email protected] hydrolyzed to extract the phenolic compounds in 60 °C or 90 °C water Fawzy M. Hashem bath for 2 hrs and the supernatants were collected after centrifugation. University of Maryland Eastern Shore, Princess Anne, MD; The supernatants were used to determine the TP and TF contents us- [email protected] ing colorimetric assays, and the quercetin content as aglycone using a Ginger is an important spice horticultural crop with variety of nutritional HPLC. The results showed that the choice of plant part significantly and medicinal uses where its optimum growth requires large amount affected quercetin content and the temperature significantly affected of nutrients application. Excessive poultry compost applications on the all the variables measured. Plant part had significantly interacted with Delaware, Maryland, and Virginia Peninsula may be potential inexpen- temperature affecting quercetin contents. Overall the flowering tops had greater TP, TF, and quercetin contents compared to the leaves, and sive nutrient sources for growing ginger. In this study the propagation of ginger from rhizomes was investigated in the greenhouse where extraction at 90 °C temperature increased all the biomarker contents as compared to those of 60 °C. The TP, TF, and quercetin contents poultry compost and Promix were mixed at ratios ranging from 0% to 15%. Ginger seedlings were also transplanted in the field where poultry in flowering tops at 90 °C were about 24 mg gallic acid equivalents -1 (GAE), 92 mg quercetin equivalents (QE), and 0.31 mg quercetin per compost was applied at rates ranging from 0 to 27 t·ha . Plants did not receive any chemical fertilizers. Plants were harvested and number, g dw powder, respectively. The values for the flowering tops at 60 weight and type of rhizomes were determined. The ability of ginger °C were 18 mg GAE, 71 mg QE, and 0.061 mg quercetin per g dw plants to hyperaccumulate nutrients, such as nitrogen (N), phospho- powder, respectively. The greater biomarker contents in the flowering rous (P), ferrous (Fe), copper (Cu), zinc (Zn) from soil amended with tops may be due to the accumulation of those compounds in forming various concentrations of poultry compost was also examined. Results seeds. The higher temperature may have increased the acid hydrolysis showed that ginger plants grown in the greenhouse at the rate of 5.0% of flavonoid glycosides into free aglycones. In conclusion, these data and 7.5% poultry compost were significantly taller, healthier and had indicated that plant part and the extraction temperature play a role in higher numbers of primary, secondary and tertiary rhizomes than those determining the biomarker contents present in cilantro. grown in Promix amended with any other ratios. However, growth (158) Comparison of Conventional and Organic of ginger and number of rhizomes were significantly decreased with increasing compost/Promix ratios to 10 and 15%. Results of the field Production of Basil Accessions in North Alabama experiments indicate that ginger growth was also enhanced with the Cedric A. Sims* addition of poultry compost at rates up to 10 t·ha-1, then significantly Alabama A&M University, Normal, AL; [email protected] decreased with increasing the poultry compost rates. The soil and Rao Mentreddy plant chemical analyses show that the concentrations of N, P, Cu, and Alabama A&M University, Normal, AL; [email protected] Zn increased significantly by increasing the rates of poultry compost Basil (Ocimum spp.), belonging to mint family, Lamiaceae (Labiatae), applications. On the contrary, the concentrations of Fe and Al were is a popular herb grown for the fresh market or for its dried aromatic not significantly affected by increasing the rate of poultry compost leaves which are used as a spice or in potpourries. In the Asian countries, applications. In the greenhouse study when the rates of poultry com- basil, particularly O. tenuiflorum is better known as a medicinal herb post application increased from 0% to 15%, the ability of the plants to used for treating ailments ranging from colds to complex diseases such hyperaccumulate N, P, Zn, and Cu increased by 124%, 202%, 198%, as cancers and diabetes. In the U.S., however, it has a limited acceptance and 190%, respectively. Similar trend was also observed in the field as a fresh market herb. There is much potential for developing basil studies. In these studies, the ability of ginger to uptake P, Zn, and as a medicinal plant to cater to the growing herbal medicinal products Cu increased by 40%, 88%, and 115%, respectively. It is concluded industry in the U.S. A field trial was therefore, conducted to compare

1182 HORTSCIENCE, VOL. 44(4), JULY 2009 conventional and organic production of basil in Alabama. Six-week J. Burand old seedlings were transplanted from the greenhouse into field plots University of Massachusetts, Amherst, MA; [email protected]. arranged in a randomized complete-block design with four replica- edu tions. Three Ocimum accessions, Ames 23154, Ames 23155, and PI L.E. Craker* 288779 were main plot treatments. The accessions were compared University of Massachusetts, Amherst, MA; [email protected] for growth, leaf area development, photosynthetically active radiation Natural insecticides have been used in Egypt and some other locations (PAR) interception, canopy cover, and fresh matter accumulation and for pest control in crops, offering an effective alternative to synthetic partitioning pattern over conventional and organic production. Ames pesticides. To determine the active principles in the plant materials used 23154 produced higher above ground biomass in conventional (1214.81 in Egypt, three species of the Chenopodiaceae family [Atriplex farinosa g/m2) than accessions PI 288779 (1176.44 g/m2) and Ames 23155 Forssk., Atriplex nummularia Lindl., and Haloxylon salicornicum (617.44 g/m2). Ames 23154 produced greater biomass in conventional (Moq.) Bunge ex Boiss.] and one species in the Resedaceae family (1214.81 g/m2) and in organic (940.55 g/m2) compared to Ames 23155 (Ochradenus baccatus Delile) were investigated. Plant material from and PI 288779. Among agronomic practices, conventional appeared each of the target species was ground and the constituents separated to be optimum as all accessions produced a significantly greater mean by column chromatography. Insecticidal activity of the isolated com- canopy, intercepted higher percentage PAR and produced significantly pounds was tested in feeding, contact, and egg hatchability tests using more total biomass and leaf fresh weight than organic basil production. Helicoverpa zea (Boddie), a major agricultural pest that as a larvae Basil leaves are consumed fresh for alleviating minor ailments and in feeds on numerous crops, including cotton (cotton bollworm), corn culinary preparations such as soups, salads, and pesto. PI 288779 parti- (corn earworm), and tomato (tomato fruitworm). Highest mortality of tion greater fresh leaf biomass conventional (472.63 g/m2) and organic the larvae occurred when the larvae were in contact with extracts from (403.8 g/m2), which are primary source of bioactive compounds in A. farinosa. Extracts from A. nummularia and H. salicornicum also basil than any other accession in conventional and organic production. exhibited activity against the larvae. Similar trends were determined Genotypic variation for fresh biomass partitioning and relationship on the hatchability of eggs, but no significant effects were detected in among horticultural traits as influenced by conventional and organic feeding tests. production will be discussed in this presentation. Specified Source(s) of Funding: credit card (159) Development of a Miniaturized 24-Well Strawberry Leaf Disk Bioassay for Evaluating (161) Yield and Quality of Domestically Grown Natural Fungicides Chinese Medicinal Plants Xiaoning Wang* Zoë Gardner The University of Mississippi, University, MS; [email protected] University of Massachusetts, Amherst, MA; [email protected] Stephen J. Cutler L.E. Craker* The University of Mississippi, University, MS; [email protected] University of Massachusetts, Amherst, MA; [email protected] Nurhayat Tabanca Interest and demand for Chinese medicinal plants in the U.S. is expand- National Center for Natural Products Research, University, MS; ing due to increases in the number of practicing acupuncturists and their [email protected] use of herbal formulas as part of treatment procedures. Recent reports David E. Wedge of contaminated goods imported from China have raised concerns National Center for Natural Products Research, University, MS; about the quality of imported medicinal plant material, leading to [email protected] demand for plants produced under controlled and documented condi- There is great incentive to discover biologically active natural products tions in accordance with good agricultural practices. To evaluate the potential of domestic cultivation of selected Chinese medicinal plants from higher plants that are more effective than synthetic agrochemicals POSTERS–Tuesday and are environmentally safe. Research emphasis at the U.S. Department in the northeastern region of the United States, cultivation trials were of Agriculture has therefore been on the development of alternative done with Agastache rugosa (Fisch. & C.A. Mey.) Kuntze, Leonurus approaches to utilizing natural plant products in pest management. Dis- heterophyllus Sweet, L. sibiricus L., and Schizonepeta tenuifolia Briq. covery and evaluation of natural product fungicides is largely dependent The plants were seeded in the field in a randomized complete block upon the availability of miniaturized antifungal bioassays. We report on design in plots containing 0, 100, or 200 kg·ha-1 of nitrogen supplied the development of a miniaturized 24-well leaf disc assay for evaluating as soybean meal. The nitrogen treatments resulted in a dose-related plant extracts and pure compounds. Compounds applied directly to the increase in yield for all the species. A comparison of natural air dry- leaf surface can be evaluated in a dose-response for fungicidal activity ing and forced hot air drying resulted in different drying times, but no and phytotoxicity. The assay is sensitive to microgram quantities, can apparent differences in quality. Preliminary organoleptic evaluation determine chemical sensitivity between fungal isolates, and adaptable indicates that domestically produced plant material has a higher quality to complex mixtures, lipophilic extracts, and non-polar compounds. than imported plant material. The use of digital imaging and analytical software provided quantita- Specified Source(s) of Funding: credit card tive data and the ability to fine tune the data analysis. Identification of new potential lead compounds can be repeated quickly in time and (162) Irrigation and Mechanization for Seed real on-the-leaf-surface activity can be evaluated in high throughput formats and published in a reasonable time. Production of Sulfur Buckwheat, a Native Forb Clinton Shock* Specified Source(s) of Funding: USDA–ARS Natural Products Utiliza- Oregon State University, Ontario, OR; [email protected] tion Research Unit Erik B.G. Feibert (160) Insecticidal Activity of Some Plant Extracts Oregon State University, Ontario, OR; [email protected] A.M. Donnia Lamont D. Saunders Desert Research Center, Cairo; [email protected] Oregon State University, Ontario, OR; [email protected]

HORTSCIENCE, VOL. 44(4), JULY 2009 1183 Nancy L. Shaw And the fruit peels treated with 10 or 25 mg·L-1 of proline amino-acid USDA Forest Service, Boise, ID; [email protected] fertilizer showed higher contents of lysine than those on the other Ram K. Sampangi treatments. The contents of hydroxyproline and lysine in apple flesh University of Idaho, Parma, ID; [email protected] were significantly increased in the all treatments of the fertilizer. But there was no hydroxyproline contents in the fruit flesh of control trees. S. Krishna Mohan -1 University of Idaho, Parma, ID; [email protected] The application of 10 mg·L proline amino-acid fertilizer showed the highest glutamic acid contents in the ‘Fuji’ apple flesh. Sulfur buckwheat (Eriogonum umbellatum) is one of many forbs na- tive to the intermountain west of the United States. Sulfur buckwheat (136) Cottonseed and Canola Meal as Organic has been selected for use in rangeland revegetation. Like many native Fertilizers for Landscape Plants plants, seed production technology is virtually unknown for wild Eriogonium species. Commercial seed production is necessary to Kathryn Fine* provide the quantity of seed needed for rangeland restoration efforts. Oklahoma State University, Stillwater, OK; katie.fi[email protected] The seed production response of sulfur buckwheat to irrigation was Janet Cole tested in 2006, 2007, and 2008 at the Malheur Experiment Station in Oklahoma State University, Stillwater, OK; [email protected] the Treasure Valley of eastern Oregon and southwestern Idaho. Sulfur Plants need large amounts of nitrogen (N) and other nutrients for proper buckwheat was established in 2005 by direct drilling of the seed in rows growth and development. Essential nutrients can be supplied by vari- 30 inches apart. Irrigation treatments were applied to plots four rows ous sources including organic fertilizers. This study was conducted to wide and 30 feet long arranged in a randomized complete-block design determine the effect of using cottonseed and canola meals as organic with four replicates. Irrigation was applied using drip tape installed fertilizers on the growth and ornamental quality of landscape plants. at 12 inch depth between two rows of plants spaced 30 inches apart. This information can help identify alternative organic fertilizer sources The drip tapes were installed on alternating inter-row spaces (5 feet and dispose of excess meal. The effects of incorporating or topdress- apart). Sulfur buckwheat was submitted to three irrigation rates: 0, 1, ing with cottonseed meal with or without soapstock, canola meal and 2 inches of water applied starting at the beginning of flowering without soapstock, urea, or no amendment (control) were investigated four times for a total of 0, 4, and 8 inches. Weeds were controlled by using plants of marigold (Tagetes erecta ‘Inca II Gold’) and Redbud mechanical cultivation, hand weeding, and broadcast applications of (Cercis canadensis) in a Norge loam (fine-silty, mixed, thermic Udic herbicide. Insect and disease pests were not noted. Seed was harvested Paleustolls) at Stillwater, OK. Fertilizers were applied at a rate based using a Wintersteiger Nurserymaster small plot combine with a dry on standard N recommendations for landscape plants (4.9 g·m-² N) bean concave. Seed was cleaned mechanically. In 2006, seed yield in May 2008. In each plot, two redbud seedlings were planted 1.5 m increased with increasing water applied up to the highest amount tested apart or four marigold plants were planted 30 cm apart. A buffer zone of 8 inches. In 2007 and 2008, seed yield showed a quadratic response was left between the end of each plot and the plants, and polyethylene to irrigation rate. Seed yields were maximized by 8.1 inches and 7.2 edging was installed between plots to reduce movement of nutrients. inches of water applied in 2007 and 2008, respectively. Each treatment was replicated 10 times for each species. Plants were Specified Source(s) of Funding: U.S. Forest Service, BLM, Oregon measured at planting in May and again in July. Soil samples were State University collected prior to treatment application and in August for elemental analysis. Leaf samples were collected in August for elemental analysis. Few differences occurred among fertilizer sources and between ap- Horticultural Crops Culture and Management: plication methods within fertilizer source for either species. Between Plant Nutrition 2 May and July, redbud trees receiving incorporated urea grew more in Tuesday, 28 July 2009 12:00–12:45 pm height and caliper than those topdressed with urea. Redbuds receiv- ing urea as a topdress treatment increased in caliper more than those (135) Changes of Amino Acid Compositions in the receiving incorporated urea. Redbuds receiving cottonseed meal with soapstock incorporated had greater increases in caliper than with cot- Leaf and Fruit of ‘Fuji’ Apple Trees as Influenced by tonseed meal as a topdress. No differences in redbud leaf elemental Applications of Amino-Acid Fertilizer content occurred. For marigolds, height increased more in control plots Ik-Jo Chun* than in plots receiving incorporated cottonseed meal with soapstock. Andong National University, Andong; [email protected] Differences in leaf calcium, sulfur, nickel, and total N content occurred Taewan Kim in marigolds. No difference in soil nutrient content occurred among Andong National University, Andong; [email protected] fertilizer treatments for either redbuds or marigolds. Cottonseed and canola meal would be expected to release nutrients slowly, thus treatment The aim of the study was to examine whether ‘Fuji’ apple tree can take differences may be more apparent during the 2009 growing season. up amino acid from foliar spray. Different proline concentrations in Results indicate that canola and cottonseed meals provide sufficient liquid amino acid fertilizer were sprayed on ‘Fuji’ apple trees grafted N for the growth of landscape plants. on M.26 rootstock. The applied amino acid fertilizer contains hydroxy- proline, serin, cystine, leucins, lysine and nitrogen. Leaf, fruit skin, Specified Source(s) of Funding: Funded by the Oklahoma Center for and fruit flesh were collected and stored at –70 °C until the contents the Advancement of Science and Technology (OCAST) through the of amino acids were analyzed. Apple leaves mainly had phophoserine, Oklahoma Applied Research Support (OARS) program hydroxyproline, serin, and lysine. The amounts of amino acid in leaves did not show any statistical differences among treatments. However, the (137) Effects of Ammonium to Nitrate Ratios on contents of amino acids on fruit peel and flesh were affected by foliar Substrate pH Shifts During Growth of Calibrachoa spray of amino acid fertilizer. Compared with control, all of amino with Alkaline Water acid fertilizer treatments increased the phosphoserin contents in apple peel. The fruit peels treated with 50 or 100 mg·L-1 of proline amino Matthew D. Taylor* acid fertilizer had significantly higher citruline than those on control. Longwood Gardens, Kennett Square, PA; [email protected]

1184 HORTSCIENCE, VOL. 44(4), JULY 2009 Dieter Lohr substrate without plants, concentrations of ammonium remained low Institut für Gartenbau. Weihenstephan University, Freising; dieter. during the first 4 weeks, rose to a peak around week 8, declined until [email protected] around week 30, and remained low thereafter. Nutrient uptake by de- Calibrachoa is considered an iron inefficient plant that commonly veloping root systems significantly reduced leachate concentrations of has problems with iron deficiency. This problem is often the result of ammonium from week 8 and throughout most of the remaining weeks high substrate pH, rather than an undersupply of the nutrient. Fertilizer of the study, with the most notable uptake indicated by reductions in composition can cause substrate pH to decrease or increase and the ammonium in leachates during the period of maximum nutrient release. direction of the shift is controlled primarily by the form of nitrogen. Concentrations of nitrate also generally remained low during the first 4 + weeks, rose to peak around week 8, then decreased and stabilized for the Fertilizers high in NH4 have an acidifying effect and the opposite is - remainder of the study in all substrates except the substrate containing true for fertilizers high in NO3 . The purpose of this experiment was to determine the ammonium to nitrate ratio that would hold substrate pH Osmocote. Nitrate concentrations in leachate from substrate contain- constant for Calibrachoa grown with either deionized (DI) water or ing Osmocote tended to be more stable compared with other fertilizer tap water with high alkalinity. Calibrachoa hybrid ‘Superbells Royal treatments, and were otherwise similar to the other fertilizer treatments Blue’ plants were greenhouse grown and received irrigation with two in most weeks from around week 17 to the end of the study. Nutrient concentrations of water alkalinity (0 and 300 ppm calcium carbonate update by the growing plants was evident by consistent reductions in equivalent) and 5 different fertilizer treatments with ammonium to ni- leachate nitrate concentrations from week 18 to the end of the study. trate ratios of 90:10, 70:30, 50:50, 30:70, and 10:90. Substrate pH was Concentrations of phosphorus in leachates from substrate without plants determined every two weeks by calcium chloride substrate extraction. generally tended to be at their highest (with some fluctuation) during When plants were grown with DI water, substrate pH decreased over the first 10 weeks of the study. From week 9 to the end of the study, time regardless of fertilizer treatment. Plants that received fertilizer presence of growing plants resulted in a mostly consistent reduction treatments with the two highest amounts of ammonium had the lowest in phosphorus concentrations in leachate. end-of-crop substrate pH of 4.4 and as the amount of ammonium in the Specified Source(s) of Funding: Department, College, State, and/or fertilizer decreased, end-of-crop substrate pH increased significantly to HATCH 5.2. When plants were grown with highly alkaline tap water, substrate pH increased over time regardless of fertilizer treatment. When plants (139) Leachate Concentrations of Ammonium, were fertilized with 90% nitrate end-of-crop substrate pH was 6.2 and Nitrate, and Phosphorus as Affected by Nutrient was significantly higher than from plants that received all other fertilizer Release from Four Different Types of Controlled- treatments, which ranged from 5.8 to 5.9. These results indicate that when water is devoid of alkalinity, substrate pH may decline regardless release Fertilizers and Crop Development of of the ammonium to nitrate ratio. Indeed, the rate at which pH declines Containerized Waxleaf Privet can be controlled by the ammonium to nitrate ratio. When water alka- Eugene Blythe* linity is excessive, substrate pH may increase despite the ammonium Mississippi State University, Poplarville, MS; [email protected] to nitrate ratio. Water with this level of alkalinity is not recommended Donald Merhaut for crop production and should be blended with other sources to reduce University of California, Riverside, CA; [email protected] the strong effect on substrate pH. High ammonium fertilizers alone may not be able to counter act the increase in pH and may also reduce Joseph Albano growth and increase the incidence of ammonium toxicity. USDA–ARS, Fort Pierce, FL; [email protected] Julie Newman Specified Source(s) of Funding: Institut für Gartenbau. Weihenstephan University of California Cooperative Extension, Ventura, CA; University. Freising, Germany [email protected]

(138) Leachate Concentrations of Ammonium, Concentrations of ammonium, nitrate, and phosphorus in irrigation POSTERS–Tuesday Nitrate, and Phosphorus as Affected by Nutrient leachate were measured weekly over a 47-week period from a high- fertility, neutral-pH substrate into which four types of 12-month con- Release from Four Different Types of Controlled- trolled-release fertilizers (Osmocote, Nutricote, Polyon, or Multicote) release Fertilizers and Crop Development of were incorporated. Containers of substrate were placed outdoors, with Containerized Azaleas one-half of the 2.4-L containers planted with liners of waxleaf privet (Ligustrum japonicum ‘Texanum’), while one-half of the containers Eugene Blythe* remained unplanted. In substrate without plants, concentrations of Mississippi State University, Poplarville, MS; [email protected] ammonium were highest during the first 23 weeks of the study, and Donald Merhaut remained low thereafter. Nutrient uptake by developing root systems University of California, Riverside, CA; [email protected] significantly reduced concentrations of ammonium in leachate from Joseph Albano week 6 to week 20, including some notable reductions during the USDA–ARS, Fort Pierce, FL; [email protected] period of maximum nutrient release. Beyond week 20, reductions in Julie Newman ammonium concentration in leachates with the presence of growing University of California Cooperative Extension, Ventura, CA; plants often occurred, despite the already low concentrations noted in [email protected] leachate from substrate without plants. Concentrations of nitrate in Concentrations of ammonium, nitrate, and phosphorus in irrigation leachate from substrate without plants generally remained low during leachate were measured weekly over a 47-week period from a low- the first 4 weeks, followed by maximum levels and fluctuations through fertility, acid-based substrate into which four types of 12-month con- week 23, and then lower levels with fluctuations through the remainder trolled-release fertilizers (Osmocote, Nutricote, Polyon, or Multicote) of the study. Nutrient update by the growing plants resulted in more were incorporated. Containers of substrate were placed in an unheated consistent reductions in leachate nitrate concentrations from week greenhouse, with one-half of the 2.4-L containers planted with liners 27 to the end of the study. Concentrations of phosphorus in leachates of ‘’ azalea, while one-half of the containers remained unplanted. In from substrate containing Multicote and no plants were often higher than with substrate containing other fertilizers, with reductions in these

HORTSCIENCE, VOL. 44(4), JULY 2009 1185 same concentrations often noted with the presence of growing plants. concentration 10 mg Mg/liter resulted in plants free of symptoms. Ten Reduced phosphorus concentrations in leachates from substrate with mg Mg/liter was thus considered incipient deficiency concentration of plants tended to be seen more often from week 18 to the end of the Mg in marigold. This concentration of Mg in solution yielded 1.5% Mg study than in prior weeks. in the plant shoot dry weight. In this experiment low Mg concentration in the medium, resulted in decreased Mg content and in increased Mn Specified Source(s) of Funding: Department, College, State, and/or and Ca contents, but had no effect on Fe content in the shoot tissue. HATCH This study indicates that Mg deficiency significantly reduces growth (140) Influence of Magnesium-mica Clay as a Peat- of marigold and affects their appearance. It also increases Mn uptake by plants making them susceptible to Mn toxicity. based Root Medium Amendment on Nutrient and Water Management of Poinsettia ‘Early Glory’ Specified Source(s) of Funding: USDA RMA grant award Rose Ogutu* (142) Manganese Toxicity in Marigold Lincoln University of Missouri, Jefferson City, MO; [email protected] Touria El-Jaoual* Kimberly A. Williams University of Massachusetts Amherst, Amherst, MA; [email protected] Kansas State University, Manhattan, KS; [email protected] Douglas A. Cox Magnesium-mica (Mg-mica) is a mineral clay that contains 8% Mg, 4% University of Massachusetts Amherst, Amherst, MA; [email protected] Fe and 2% K. Physical properties of peat-based media with 2, 5, and Iron/manganese (Fe/Mn) toxicity disorder in marigold has been related 10% raw Mg-mica were characterized. Air-filled porosity decreased to high concentrations of Mn in the affected leaves. In greenhouse crop from 17% in the 70 peat: 30 perlite control to 13% in mixes of 60 peat: production, preplant addition of micronutrients in the media combined 5 Mg-mica: 35 perlite, and container capacity increased from 57% in with constant feed program and low medium pH, create favorable the control to 80% for the mixes with 5% Mg-mica. In a greenhouse conditions for the development of Mn toxicity. To investigate the experiment, Euphorbia pulcherrima Willd. ex Klotzsch ‘Early Glory’ effect of excess supply of Mn on marigold (Tagetes erecta L. ‘First were grown with treatments of 3 root media (5 uncalcined Mg-mica: Lady’) growth, appearance, and nutrient [Mn, Fe, Calcium (Ca), and 55 peat: 40 perlite, 5 calcined Mg-mica: 55 peat: 40 perlite and 70 peat: magnesium (Mg)] concentrations, a solution culture study with vari- 30 perlite control) × 2 fertilizer regimes (20 N–4.3 P–16.6 K without ous Mn concentrations was conducted. Concentrations of Mn equal or with Mg). Planted and fallow pots of the treatment mixes were used or above 6.5 mg/L in the nutrient solution, resulted in stunted plants to evaluate initial wettability, rewettability, and water retention. Plant with significant number of small brown spots, interveinal chlorotic growth and tissue nutrient concentrations were determined at mid- and patches, and necrotic symptoms on the tips and margins of the leaves. end-crop, and cations in leachate were measured over the course of the The concentration 4.5 mg/L resulted in stunted plants free of symp- production cycle. Calcining Mg-mica and using fertilizer with Mg did toms. Concentrations below 4.5 mg/L Mn resulted in healthy looking not influence results. Compared to the control, clay treatments resulted plants. The concentration 4.5 mg/L Mn in the nutrient solution, may in ~0.5 unit higher pH during the first month of the production cycle, but thus be considered critical toxicity concentration of Mn in marigold. EC was not influenced. Mixes with Mg-mica released Mg and Ca into This concentration yielded 596 mg Mn/Kg total plant tissue dry weight, the root medium solution, but neither growth nor cation uptake were 1400 mg Mn/Kg dry weight in the tissue of the roots, 360 in the stems, influenced in a commercially-meaningful way. Mixes with Mg-mica 880 in the new leaves, and 1200 in the old leaves. Using the methods retained NH -N, but this did not affect plant growth. The clay amend- 4 of this experiment, excessive supply of Mn increased the concentra- ments favorably impacted physical properties of initial wettability, tion of Mn in the roots and leaves, increased the concentration of Fe rewettability, and water holding capacity. The volume of water retained in the roots, and increased the overall concentration of Ca and Mg in per unit volume of root media with Mg-mica clay (0.42–0.44 cm3·cm3) the plant. Concentrations of Mn above 4.5 mg/L in the nutrient solu- was almost twice as great compared to the commercial control (0.24 tion, or above 596 mg Mn/Kg total plant tissue dry weight, result in cm3·cm3). Media amended with Mg-mica had greater water retention Mn toxicity in marigold. as indicated by rewet volumes that were 17% to 30% higher than the commercial control. The Mg-mica amendment improved root medium Specified Source(s) of Funding: USDA RMA Grant Award nutrient retention and released Ca and Mg but did not influence plant growth. Media amended with Mg-mica resulted in easier wetting (143) Manganese Toxicity in Marigold as and rewetting and had increased water holding capacity; therefore, Affected by Magnesium the clay could be used as a substitute for synthetic wetting agents in Touria El-Jaoual* peat-based root media, and its use would decrease irrigation frequency University of Massachusetts Amherst, Amherst, MA; [email protected] during production. Douglas A. Cox Specified Source(s) of Funding: Industry University of Massachusetts Amherst, Amherst, MA; [email protected] (141) Magnesium Deficiency in Marigold Iron/manganese (Fe/Mn) toxicity disorder in marigold has been related to high concentrations of Mn and low concentrations of magnesium Touria El-Jaoual* (Mg) in the affected leaves. Preplant addition of micronutrients in the University of Massachusetts Amherst, Amherst, MA; [email protected] media combined with constant feed program, and low medium pH create Douglas Cox favorable conditions for the development of Mn toxicity in greenhouse University of Massachusetts, Amherst, MA; [email protected] crops. Deficiency of Mg is due in part to low medium pH and to lack To investigate the effect of poor supply of magnesium (Mg) on marigold of Mg in many of the fertilizers used in greenhouse production. To (Tagetes erecta L. ‘First Lady’) growth, appearance and nutrient [Mg, investigate the effect of Mg on Mn toxicity effects (growth, appearance, calcium (Ca), iron (Fe), and manganese (Mn)] content of the shoots, a and nutrient concentrations) on the plant, a solution culture study with solution culture study with various Mg concentrations was conducted. various Mg and Mn concentrations was conducted in the greenhouse. Concentrations of Mg up to 8 mg/L resulted in stunted plants with a In this experiment, the treatments 10/6.5, 10/4.5, 5/6.5, and 5/4.5mg/L significant amount of chlorotic and necrotic symptoms on the leaves. A Mg/Mn solution concentrations resulted in stunted plants with significant

1186 HORTSCIENCE, VOL. 44(4), JULY 2009 number of small brown spots, interveinal chlorosis and necrotic symp- (145) Growth and Flowering Responses of toms on the tips and margins of the leaves, which are typical symptoms Container-grown Marigold to Organic and of Mn toxicity in marigold. The treatments 10/0.5, 15/4.5, and 20/4.5, resulted in stunted plants free of symptoms. Treatment 20/6.5 and 15/6.5 Inorganic Fertilizers resulted in stunted plants with Mn toxicity symptoms. The treatment Guihong Bi* 20/0.5 and 15/0.5 resulted in fully-grown and healthy looking plants. Mississippi State University, Crystal Springs, MS; [email protected] Concentrations of Mg as high as the incipient deficiency concentration William Evans reduced the critical toxicity solution concentration of Mn in marigold Mississippi State University, Crystal Springs, MS; [email protected] from 4.5 to 2.5 mg/L. High concentrations of Mn (above 2.5 mg/L) Dennis Rowe in the nutrient solution affected the plant appearance and reduced the Mississippi State University, Starkville, MS; [email protected] dry weight of the plants. High Mn also increased the concentration of Mn in the roots and leaves, increased the concentration of Fe in Two separate experiments were conducted to evaluate the growth and the roots, reduced the concentration of Fe in the stem and old leaves, flowering responses of container-grown greenhouse marigold plants to reduced the concentration of Calcium (Ca) in the leaves, and reduced four rates of two non-composted broiler chicken litter-based organic the concentration of Mg in the plant. Magnesium concentration in the fertilizers 4–2–2 at 1%, 2%, 4%, and 6% (by volume) and 3–3–3 at nutrient solution had no significant effect on the effect of excessive 1.34%, 2.67%, 5.34%, and 8.0% (by volume) and a commonly used Mn in the medium on Mn, Fe, Ca or Mg concentrations in the plant synthetic controlled-release fertilizer 14–14–14 at 0.99, 1.98, 3.96, -3 tissue. Under the conditions of this experiment, Mg did not affect the and 5.94 kg·m . For the fertilizer rates used in this study, in general, effect of excess Mn in the medium on Mn content in the plant tissue, increasing 14–14–14 fertilizer rate increased plant growth and flowering but Mg deficiency reduced the medium critical toxicity concentration performance. However, low to intermediate rates of 4–2–2 and 3–3–3 from 4.5 mg/L to 2.5/L. Concentrations of Mg, equal or lower than the produced the highest plant growth index, shoot dry weight, number incipient deficiency concentration (10 mg/L nutrient solution) increased of flowers per plant, total flower dry weight, and root rating. Plants the sensitivity of marigold to high concentrations of Mn in the medium grown in high rates of 4–2–2 and 3–3–3 showed symptoms associated (concentrations of Mn above 2.5 mg/L nutrient solution). with excessive fertilizer. Results from this study indicated that 4–2–2 and 3–3–3 have the potential to be used as organic fertilizer sources Specified Source(s) of Funding: USDA RMA Grant Award for container production of marigolds in greenhouses. However, grow- (144) Nutrient Management of Potted Dendrobium ers need to be cautious with the rate applied. Since different crops may respond differently to these natural fertilizers, it is important for and Oncidium Orchids growers to test new fertilizers before incorporating them into their Kent D. Kobayashi* production practices. University of Hawaii at Manoa, Honolulu, HI; [email protected] (146) Container-grown Holly Response to With the difficulty of consistently obtaining high quality peat moss Phosphorus due to availability and cost, an alternative potting media component would be desirable for orchid production in Hawaii. Coir fiber offers Thomas Yeager* a possible low cost alternative. A study with potted dendrobium and University of Florida, IFAS, Gainesville, FL; yeagert@ufl.edu oncidium orchids was conducted at the University of Hawaii Magoon Claudia Larsen Greenhouse Facility. The oncidium orchid was Brassia Haleahi Spi- University of Florida, IFAS, Gainesville, FL; calarsen@ufl.edu der ‘Golden Swords’ × Brs. Caudata, and the dendrobium orchid was Controlled-release fertilizers (CRFs) often contain higher than 1.3% Dendrobium Jaquelyn Thomas (UH232) ‘Uniwai Supreme’. Two P. Phosphorus applied in excess of plant demand is leached and likely potting media were used—a 3:1 (by volume) black volcanic cinder: transported in runoff from the nursery site. One approach to achieving a peat moss mixture and 3:1 black volcanic cinder:coir fiber mixture. reduction in P loss from the nursery is to reduce the amount of P applied. POSTERS–Tuesday Nutricote controlled release 13 N–13 P–13 K fertilizer was applied at In our experiments, multiple-branched liners of Ilex cornuta ‘Burfordii two rates—0.5 g and 1.0 g per 10.2-cm pot. Oncidium orchids: with the Nana’, Ilex crenata ‘Helleri’, and Ilex vomitora ‘Nana’ were potted cinder:peat moss media and the cinder:coir potting media, the higher August 2006 with 10 L of a common nursery substrate. The substrate fertilizer rate resulted in a taller plant and more leaves compared to was amended with 4.2 and 0.9 kg/cubic meter of dolomitic limestone the lower rate. With both media, the number of flowers per plant was ® and Micromax micronutrients, respectively, and amended with 46 g similar for both fertilizer rates. The percentage of plants that flowered of a CRF that differed in P content [18N–0P–10K, 18N–0.4P–10K, was similar for the two fertilizer rates for each media. The percentage 18N–1.3P–10K, or 18N–2.6P–10K (Harrell’s Inc., Lakeland, FL)]. flowering was higher with the cinder:peat moss media. Dendrobium Twenty plants were grown with each CRF under natural light and orchids: with the cinder:peat moss media and the cinder:coir potting each container was irrigated with approximately 400 ml as needed. media, the higher fertilizer rate resulted in a taller plant and more After 18 months, shoot and root dry weights of Ilex cornuta ‘Bur- leaves compared to the lower rate. With both media, the number of fordii Nana’ were greatest for plants that received 18N–0.4P–10K and flowers per plant was similar for both fertilizer rates. For each media, 18N–2.6P–10K, and Ilex crenata ‘Helleri’ responded similarly after 16 the percentage of plants that flowered was higher with the higher rate months. Shoot and root dry weights were not different after 17 months of fertilizer. The percentage flowering was similar for the two media. for Ilex vomitora ‘Nana’ that received P in the CRFs. Substrate pour- This study has shown that coir fiber may be a suitable alternative to peat through P ranged from a high of 10 mg/L at week 8 for the substrate moss in a volcanic black cinder potting media for orchid production amended with 18N–1.3P–10K to 0 mg/L at week 24 for substrate in Hawaii. Use of a lower fertilizer application rate could help reduce amended with 18N–0.4P–10K. These results indicated that CRF with leaching of nutrients from the pots, minimize environmental impacts, 0.4% P was adequate for production of the holly species tested and its and reduce fertilizer costs to the grower. use in lieu of a CRF with a higher P content would be considered a Specified Source(s) of Funding: Federal Floriculture Research Grant; best management practice. Hatch

HORTSCIENCE, VOL. 44(4), JULY 2009 1187 compared to a control with more complete saturation when used on Horticultural Crops Culture and Management: benches or floors. The amount of water taken up in a single watering Water Utilization could be varied from 30% to more than 70% of root medium volumetric water content (VWC), depending on the time of contact with water. Tuesday, 28 July 2009 12:00–12:45 pm When used repeatedly to grow a crop, plants took up 20% to 30% less water and fertilizer with PSEFW compared to control watering. (147) Vegetated Floating Mats Effectively The average VWC was 10% less with PSEFW compared to controls. Remediate Nutrients The water stress resulting from PSEFW reduced biomass until flower development and bloom, and stem height, by 10% to 20% compared Sarah A. White* to control watering. Clemson University, Clemson, SC; [email protected] Matthew Cousins Specified Source(s) of Funding: USDA SBIR 2006-33610-17175 Clemson University, Clemson, SC; [email protected] (149) Recycling Nutrient Solution for Greenhouse Brandon Seda Tomato Grown in Rockwool Clemson University, Pendleton, SC; [email protected] Martin P.N. Gent* As urbanization and concerns over deteriorating water quality increase, Connecticut Agricultural Experiment Station, New Haven, CT; martin. the importance of remediating nutrient rich runoff from agricultural [email protected] and other non-point source contributors will increase. Floating mat Michael R. Short treatment systems are potential alternatives to constructed wetland Connecticut Agricultural Experiment Station, New Haven, CT; Michael. systems for remediating nutrient rich water and can be established in [email protected] existing drainage ditches and retention ponds. This researched exam- ined the remediation efficacy of floating mat systems at two treatment Recirculation of nutrient solution, or reuse of solution after it has scales. Agrostis sp., Canna flaccida, Eleocharis montana, and Juncus once been used to water plants, is the preferred legislative solution to effusus were established in the large-scale pond system treatment, and prevent ground water pollution from intensive agricultural production. a small-scale trough system treatment was established using C. flaccida There are several potential problems that may arise due to recircula- and J. effusus. We measured plant growth parameters (shoot and root tion of nutrient solutions used to produce vegetable crops. Changes height and branching) on a biweekly basis and monitored various water in composition of nutrient solutions could ultimately have deleterious quality parameters (pH, conductivity, dissolved oxygen, temperature, effects on plant growth, product quality, and the dietary value of veg- and nutrient concentrations) weekly for five months. At harvest, plant etables. We examined the composition of a nutrient solution as it was shoots and roots were harvested, dried, ground, and analyzed for mineral continuously recirculated to a greenhouse tomato crop, in comparison content. Nitrogen and phosphorus effluent concentrations averaged 0.13 to solutions that were used to water plants only once. Crops were grown ± 0.03 mg/L N and 0.02 ± 0.003 mg/L P after treatment. Of the plant in spring and summer in two years in a heated greenhouse using rock species examined, Canna and Juncus nitrogen and phosphorus tissue wool as the root medium. The difference in composition of recycled concentrations were highest when normalized by total plant biomass. compared to discharged solution developed over more than one month When normalized on a per unit area basis, Juncus shoots and roots fixed of recycling. Typically, the transition from vegetative to fruit growth, the most phosphorus of any species examined, respectively fixing 184.0 which coincides with the beginning of the warm season, resulted in and 110.3 mg P per m2 area. The floating mat systems were easy to over-supply of nitrate, potassium, and other nutrients. It took a longer install, maintain, and harvest. These systems may prove most effective time to return the solution to an optimal composition with recycled in low nutrient environments where “polishing” effluent water quality compared to discharged solution. There was little effect on composition to very low phosphorus concentrations is necessary. of plants, despite the large but temporary differences in composition of nutrient solution. Yield components of cultivars tended to differ in Specified Source(s) of Funding: Beeman’s Nursery response to recycling. (148) Rapid Watering to Achieve Partial Saturation Specified Source(s) of Funding: Hatch CONH000569 of Root Medium on Flooded Floors (150) NCDC216: A New Multistate Group for Water Martin P.N. Gent* Management and Quality for Ornamental Crop Connecticut Agricultural Experiment Station, New Haven, CT; martin. [email protected] Production and Health Wade H. Elmer R. Thomas Fernandez* Connecticut Agricultural Experiment Station, New Haven, CT; Wade. Michigan State University, East Lansing, MI; [email protected] [email protected] John Lea-Cox Richard McAvoy University of Maryland, College Park, MD; [email protected] University Connecticut, Storrs, CT; [email protected] Gladis Zinati Sub-irrigation for production of potted ornamental plants combats the Rutgers University, New Brunswick, NJ; [email protected] waste of water and fertilizer in traditional overhead watering systems Chuanxue Hong used in greenhouses. However, current ebb and flow watering systems Virginia Polytechnic Institute and State University, Virginia Beach, VA; for flooded floors operate slowly. The root medium takes up water [email protected] to near saturation during each watering cycle. There is no ability to Raul Cabrera restrict the water provided to the plants. We have examined a system Texas A&M University, Dallas, TX; [email protected] to rapidly deliver and remove water. Less water is absorbed by the Donald Merhaut pots, and little leaked back out of the pots. This improves plant quality University of California, Riverside, CA; [email protected] and prevents spread of disease. We examined several parameters that Joseph Albano vary between this partial saturation ebb and flow watering (PSEFW) USDA–ARS, Fort Pierce, FL; [email protected]

1188 HORTSCIENCE, VOL. 44(4), JULY 2009 Marc Van Iersel to quantify the effects of varying irrigation regimes on the growth and University of Georgia, Athens, GA; [email protected] physiology of common Christmas tree species in pot-in-pot production. Thomas Yeager Four species of conifers (Abies fraseri, Picea pungens, Picea glauca University of Florida, IFAS, Gainesville, FL; yeagert@ufl.edu var. densata, Pinus strobus), grown in 3- and 7-gallon containers, were Douglas Buhler randomly assigned to irrigation regimes with varying combinations of Michigan State University, East Lansing, MI; [email protected] amounts (low, medium, high) and cycle frequencies (once or 4 times daily). Daily amounts for 3-gallon containers were based on 75%, 150%, We have established a USDA multistate development committee or 225% PET, and amounts for 7-gallon containers were based on 75% (NCDC216) to create a project focused on water management and or 150% PET. Water was applied using pressure compensating drip quality for ornamental crop production and health. The nursery and emitters or spray stakes. Mid-day gas exchange and monthly tree caliper greenhouse industry ranks 5th (>$14.6 billion) among all US agriculture and height were measured during the 2008 growing season. Diurnal gas commodities and within the top 5 commodities in 26 states according exchange and water potential of 7-gallon A. fraseri were measured on to the USDA. The quantity and quality of water available for irrigation two dates during the growing season, and substrate media temperature has major consequences on the productivity and profitability of this and moisture of 7-gallon containers were monitored throughout the important sector of agriculture. The record 2006–2008 drought in the season. Preliminary data indicate a strong species effect on growth eastern US had a severe negative impact on the nursery industry in that response to irrigation regimes. P. strobus and P. pungens grown in 3 region. The Great Lakes region is implementing water use policies in gallon containers and receiving 4× daily irrigation applications had order to comply with the recently ratified Great Lakes-St. Lawrence greater assimilation and caliper growth than trees of the same species River Basin Water Resource Compact. Drought and water conservation irrigated once daily, while assimilation and caliper growth of A. fraseri are not new issues to the western states where availability has long and P. glauca was unaffected by cyclic applications. Mid-day stomatal been a limitation but demographic changes are increasing competition conductance of A. fraseri, P. pungens, and P. strobus grown in 7-gal- between users. Demand from industry, homeowners and agriculture is lon containers increased with cyclic irrigation indicating that multiple increasing in almost all areas of the United States. Increased regula- applications alleviated mid-day water stress. Differences in growth tion and competition for water resources necessitates improved water and physiological responses to treatments could be due to inherent management techniques in all regions. Water is no longer an issue differences in species morphology, tree size, and growth rate. restricted to certain areas of the country with insufficient water quantity and/or quality but is a national and global issue. This national effort Specified Source(s) of Funding: Michigan Ag Experiment Station, to address water resource challenges will ensure a more efficient and Project GREEEN, Michigan Christmas Tree Association Michigan coordinated use of assets and provide research and extension programs Department of Agriculture Horticulture Fund to address this critical issue. The goals are to provide a forum to develop (152) Hydroponic Production of Selected Flower and multidisciplinary approaches to: 1) improve water efficiency and crop productivity while minimizing the risk of releasing nutrient- and chemi- Herb Crops in Red Lava Rock cal-rich irrigation runoff into natural waters; 2) de-couple crop health Sven Verlinden* risk with recycling irrigation to promote water resource conservation and West Virginia University, Morgantown, WV; [email protected]. protection; 3) investigate alternative water sources; and 4) to develop edu soilless substrates with physical and chemical characteristics that im- Victoria Gonzalez Lerma prove water an nutrient availability while reducing leaching of fertilizers. West Virginia University, Morgantown, WV; [email protected] The intent of this project is to bring together a multidisciplinary team Red lava rock has the characteristics of an excellent hydroponic media to include colleagues in horticulture, plant physiology, plant pathology, and has been used extensively as a growing media in Mexico. However, entomology, pest management, engineering, hydrology and other fields little information is available in the literature on plant production in interested in addressing water use issues. Improving water management this substrate. Four herbs, rosemary, thyme, mint, and basil, and one and quality will have several important impacts: 1) reduction in total POSTERS–Tuesday cut flower crop, sunflower, were grown under five watering regimes in water use through more efficient practices; 2) improved technology for two separate experiments to study water use and species interaction in irrigation scheduling; 3) improved crop production through increased a red lava rock media. In order to create a hydroponic media optimum water and nutrient use efficiency; 4) reduced runoff and impairment of for plant growth we designed two substrates with aeration of 13.6% natural waters; and 5) enhanced crop health and consumer confidence and 35.3% and container capacity of 16.5% and 11.0%, respectively. stemming from more sustainable practices. Plants were watered three, twice, once, every other day, and twice a (151) Growth and Physiology of Living Christmas day alternated by once a day, with a modified Hoagland’s solution at Trees Under Cyclic Irrigation 120% of container capacity. Data on fresh weight, dry weight, plant height, number of stems, and in the case of basil, number of leaves, Amanda Taylor* were collected over a period four months for each harvest of the crops Michigan State University, East Lansing, MI; [email protected] under investigation. In this period basil, thyme, rosemary, mint, and Bert Cregg sunflowers were harvested 4, 2, 2, 3, and 2 times, respectively. The Michigan State University, East Lansing, MI; [email protected] highest average fresh weights per harvest, at the optimum watering Tom Fernandez regime and substrate combination ranged from 237.2 grams for basil to Michigan State University, East Lansing, MI; [email protected] 86.8 grams per plant for sunflower. The highest average dry weights per Pascal Nzokou harvest, again at the optimum watering regime and substrate combination Michigan State University, East Lansing, MI; [email protected] ranged from 34.0 grams for basil to 15.4 grams per plant for sunflower. Watering regime showed a clear effect on fresh weight and dry weight Water use regulations and the cost of applying water are increasing as of basil, mint, rosemary, sunflowers, but not thyme. In those crops that the availability of potable water is decreasing. Irrigating cyclically, or showed an effect of watering regime on fresh weight and dry weight, applying daily water allotments in multiple irrigation events, instead a general trend was observed toward lower weights correlated to less of the traditional once daily application method may lead to increased watering. However, in most instances no differences were observed crop growth and decreased water use. The objective of this study was between watering three and two times a day or watering once day

HORTSCIENCE, VOL. 44(4), JULY 2009 1189 compared to watering twice a day alternated with once a day. Despite fertilized (using half strength Hoagland solution) plants, all six crops the severe restrictions on growth as measured by fresh weight and dry showed moderate growth and photosynthetic capacity when grown weight due less frequent irrigation, a less significant effect on height with reclaimed water. This indicates that there are limited nutrients was observed in our experiments. Based on our results we conclude available for crops to use in reclaimed water. The reduction in growth that watering on average twice a day in a red lava rock media designed and photosynthetic capacity in plants irrigated with reclaimed water for hydroponic production (high aeration) can result in good yields of compared to the fully fertilized plants appear to be a result of limited basil, mint, and rosemary, and sunflower. Thyme can be successfully nitrogen availability. Based on these results, a recommendation may be grown with only one fertigation application per day. made to practice reduced fertilization in urban farming and horticultural production when using reclaimed water from the Renton Plant. (153) Growth and Physiology of Six Horticultural Specified Source(s) of Funding: King County Government, WA Crops Irrigated with Municipal Reclaimed Water Soo-Hyung Kim* (154) Evapotranspiration in Tomato Plants University of Washington, Seattle, WA; [email protected] Grown Under Controlled Environment in Hannah Kinmonth-Schultz Mexicali Baja, California, Model Prototype University of Washington, Seattle, WA; [email protected] Based on Solar Radiation Sally L. Brown University of Washington, Seattle, WA; [email protected] Fidel Nuñez Ramirez ICA- UABC, Caborca, Sonora; [email protected] Reclaimed water from the South Treatment Plant in Renton, King Raul Grijalva-Contreras* County, Washington can be a valuable source to supply irrigation water INIFAP, Caborca Sonora 83600; [email protected] for landscape plants and urban farming in the area during the summer dry season. Currently most of the treated water at the Renton Plant is Fabián Robles Contreras discharged into Puget Sound while only a limited portion of the water INIFAP, Caborca Sonora 83600; [email protected] is treated to meet Class A reclaimed water standards by sand filtration Rubén Macias Duarte and used for turf irrigation. Potentially important users of reclaimed INIFAP, Caborca Sonora 83600; [email protected] water in the Seattle area and King County are small-scale urban farms, Manuel Valenzuela Ruiz commercial greenhouses, and nurseries for production of a range of INIFAP, Caborca Sonora 83600; [email protected] ornamental and vegetable crops. Since irrigation water is limited in The determination of evapotranspiration is one of the multiple basic many areas in King County, reclaimed water may prove to be a key elements to consider to calculate the hydric requirements of a crop. factor in maintaining the viability of these operations. Although the use Therefore, it is important to realize precise estimations of each crop and of reclaimed water for irrigation is commonly practiced in many parts for each environmental condition. There are several procedures using of the country as well as overseas, each area is likely to have unique many formulate, however they are very general and they demonstrate concerns and management requirements that need to be addressed for the local character for certain regions. Considering the previous situa- efficient and safe use of this resource. In addition to public and envi- tion, in this work a model prototype for the calculation of the monthly ronmental health concerns, there are horticultural questions that need to evapotranspiration considered for plants of tomato (Lycopersicon be addressed such as how to integrate the use of reclaimed water with esculentum Mill.) grown under controlled environment is presented, existing fertilization practices, potential impacts of reclaimed water using data of water evaporation obtained according to the received on plant growth and soil properties, and potential salinity issues. The radiation, transpiration of foliar area and estimated number of estomas. objective of this study was to evaluate plant growth and physiological Values of radiation reported for the Valley of Mexicali Baja California responses of three ornamental (Amaranthus hypochondriacus cv. Bur- Mexico was used. This model turned out to be effective to consider the gundy, Helianthus annuus cv. SunSpot, Delphinium grandiflorum cv. water needs of the tomato crop grown under controlled environment Blue Mirror) and three vegetable crops (Lactuca sativa, Daucus carota of Valley of Mexicali Baja California México subsp. sativus, Fragaria ananassa) to irrigation using reclaimed water from the Renton Plant. Compared to control (tab water only) and fully Specified Source(s) of Funding: INIFAP

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