Nursery Production of Uniola Paniculata

niola paniculata (south- ies in the Southeast commonly use Nursery ern seaoats) is the domi- pine bark–sand media, which is also Production of U nant foredune building grass nutrient-deficient (Wright and from southeastern Virginia along the Niemiera, 1987). Nurseries attempt Uniola Atlantic and Gulf coasts to eastern to maintain adequate nutrition by us- Mexico (Woodhouse and Hanes, ing quick-release granular fertilizer, paniculata 1966). This perennial grass has been controlled-release fertilizer or fertil- used extensively to build artificial dunes izer injected into irrigation water, alone (southern and stabilize existing dunes. With the or in combinations. Macronutrient fer- increased shoreline damage by tropical tilizers commonly are applied to stimu- seaoats) storms on the eastern seaboard in the late plant growth and increase vegeta- last few years, the need for beach res- tive cover in dune plantings

l toration-also has increased. Vegetative (Woodhouse and Hanes, 1966) Gary R. Bachman and propagation for dune restoration in Production of seeded Uniola Ted Whitwell2 beach sand is expensive, and young paniculata in commercial nurseries plants are subjected to extreme envi- would increase availability of plants for ronmental factors which can result in dune restoration. The objectives of poor plant establishment and growth this research were to 1 ) enhance ger- Additional index words. container (Wagner, 1964). Direct seeding in the mination of freshly harvested seed, 2) production, pine bark media, nutri- dunes is ineffective because of seed investigate the effect of planting depth tion dormancy–viability and movement of within containers to simulate the dune Summary. Demand for commercially sand which affects planting depth. environment, where the base of the grown Uniola paniculata L. (southern Uniola paniculata is not a prolific plant is buried, and 3) determine an seaoats) is increasing for use in seed produce like many grasss. Typi- optimum nutrition program for Uniola restoring beaches damaged by tropical cally panicles have many spikelets bear- panicuiata grown in pine bark-sand storms. Fresh seeds harvested from the ing 10 to 12 florets (Westra and media for nursery production. Jekyll Island, Ga area (with permission Loomis, 1966). These are usually in- of the Jekyll Island Authority), were fertile at the terminal and distal ends, Materials and methods planted in 50 peat: 50 perlite and leaving 6 to 8 fertile florets, which Seed germination. Mature treated with 100 or 500 ppm GA for 4 produce fewer than 2 seeds per spike- Uniola paniculata panicles were har- 24 h. Germination was higher for 100 let (Wagner, 1964). Sexual reproduc- vested from the Jekyll Island, Ga., area compared to 500 ppm GA4. Liners grown from seed and planted with the tion depends on wind dissemination 15 Sept. 1993 in cooperation with the crowns even with the surface of the of pollen. Successful pollination is af- Jekyll Island Authority. The spikelets pine bark-sand media, compared to fected by the florets opening and clos- were rubbed over a screen to remove deep planting to simulate burial ing only once within a 24-h period the chafe, and the seeds were col- conditions of beach planting, had the (Colosi, 1979). High humidity and lected. Harvested seeds were stored highest shoot and root weights after summer rain increase the incidence of dry at 4C for 30 days. Before treat- 100 days. Uniola paniculata liners fungal invasion. Aborted ovules in the ments all seed were soaked for 30 min with the crowns buried had reduced florets have been observed to exhibit in a 30% bleach solution as a surface weights due to higher moisture high infestations of Alterneria sp. and sterilant. Seed treatments included 24- conditions in the bottom of the containers. Uniola paniculata grown Helminthosporium sp. fungi which h soak in 100 or 500 ppm gibberillic without supplemental fertilization had completely fill the floret with hyphae acid (GA4) or distilled water. Scarifica- shoot weights similar to those of plants and conidia (Wagner, 1964). tion also was applied to the seeds across 3 3 receiving 1.5 lb N/yd (0.89 kg N/m ) The primary natural method of all GA1 treatments. Seeds were scari - from both quick or slow release reproduction in the dune habitat is fied using 600-grit sandpaper and gen- fertilizers. Increasing N to 3 lb/yd3 through vegetative means. Buds are tly rubbing the seeds between fingers. 3 (1.78 kg N/m ) and/or supplying formed around the stem base, and the A scarified only and non-treated con- micronutrients only, reduced shoot formation angle of the buds determine trol also were included. weight. Nursery production of Uniola whether shoot or lignified Seeds were planted in 40-cell trays paniculata in pine bark-sand is one rhizomaceous tissue develops (Wag- using a standard nursery seed propaga- way to increase the supply of this important dune plant. ner, 1964). Acutely angled buds be- tion media consisting of 1 peat moss : come tillers and right angled buds 1 perlite (by volume) and germinated become rhizomes. Internodal potions in a shadehouse at Carolina Nurseries, 1Former graduate research assistant. Present address The Ohio State University 2001 Fyffe, Columbus, OH 43210. of the rhizomes decay leaving the nodal Moncks Corner, S.C. Preplant fertili- 2Professor, E-142 P&A Bldg, Box 340375, Clemson regions with associated culms to root zation for all treatments included in- 3 -3 University, Clemson, SC 29634-0375 and become new plants. As sand is corporation of 9 lb/yd ( 5.34 kg·m ) Technical contribution no. 4073 of the South Carolina deposited around the base of the plant, 18N-2.6P–9.9K Osmocote and 9 lb/ Agricultural Experiment Station, Mention of a trade- these rhizomes establish roots in dune yd3 ( 5.34 kg·m-3) 14–7–7 granular fer- mark, proprietary product, or vendor does not constitute sand. tilizer (Carolina Eastern-Malloy, a guarantee or warranty of the product and does not imply its approval to the exclusion of other products or The dune habitat found along the Georgetown, S.C.). Apreplant drench vendors that may be suitable. The cost of publishing this coastal regions of the Southeast lacks of Banrot (O.M. Scotts Co., Marysville, paper was defrayed inpart by the payment of page charges. Under postal regulations, this paper therefore must be sufficient nutrients for optimal growth Ohio) at 8 lb/100 gal (3.63 kg/25.8 hereby marked advertisement solely to indicate this fact. (Wagner, 1964). Commercial nurser- liter) was applied. Seed were planted 1

295 Table 1. Germination percentages of Uniola paniculata seeds as effected by preplant treatments. planted in a 4 pine bark :1 sand (by volume) media on 15 Mar. 94 at Caro- lina Nurseries. The plants were planted with the crowns even with the top of the media in trade 1-gal (2.8-liter) containers. Fertilizers were applied at standardized rates of nitrogen, 1.5 or 3 lb N/yd3 (0.89 or 1.78 kg N/m3), on 5 Apr. 1994. The containers were topdressed with the following nursery fertilizer formulations: 1) 14-7-7 with z micronutrients granular quick release Treatments analyzed using least significant difference (LSD) mean separation. Column means with the formulation (16.2 or 32.4 g/con- same letter are not different based on P = 0.05. tainer), 2) 18–3–6 with micronutrients Osmocote Custom Blend slow inch (2.5 cm) deep with two seeds per seed-grown liners of Uniola paniculata release (12.6 or 25.2 g/container), 3 ) cell. Treatments were arranged in a were planted in a 4 pine bark : 1 sand 16–7–12 without micronutrients Os- randomized complete block design (by volume) media on 15 Mar. 1994 at mocote slow release (14.2 or 28.4 g/ (RCBD) with five blocks of each seed Carolina Nurseries. Two containerizes container) , or 4) STEP micronutri- treatment and five replicate cells per were used: 3.8 liter (19 cm diameter × ents 2 lb/yd3 STEP (3 g/container) block. 17.8 cm) and 9.2 liter (20.3 cm diam- (a complete micronutrient formula- The 40-cell trays were irrigated eter × 38.1 cm), full l-gal and 3-gal tion from O.M. Scotts Co.). The con- by mist for 5 min initially followed by tree containers respectively. The liners trol was not topdressed with addi- mist every 16 min for 8 sec during the were placed in the 3.8-liter containers tional fertilizer, however it did receive first 10 days and then every 32 min for with the crown either even with the the normal nursery practice of twice 8 sec for the remainder of the study. surface of the media or 4 inches (10 weekly fertilizer-injected irrigation, The study was started on 17 Nov. cm) below the media surface. Liners which contained 1.28 mol·liter-l -1 1993 and concluded 20 Dec. 1993. were planted in the 9.2-liter contain- Mg(NO3) 2·2H2O, 3.80 mol·liter –1 On 20 Dec. 1993, germination per- ers with the crown also 4 inches (10 KNO3, and 0.96 mol·liter K 2HPO4. centages were determined for the seed cm) below the media surface. The Treatments were arranged in a RCBD treatments. Analysis of variance and bottom of the deeply planted liners with five blocks per container treat- least significant difference determined, were either on the bottom of the 3.8- ment. Irrigation was applied using if F test was significant at P = 0.05, liter container or 20 cm above the overhead sprinklers following normal were performed on all data. container bottom for the 9.2 -liter con- nursery practice of 12.5 mm of water A follow-up study was conducted tainer. Treatments were arranged in a per day. in a glass greenhouse at Clemson Uni- RCBD with five blocks per container The study was terminated on 7 versity. Seeds collected at Jekyll Island treatment. The plants were topdressed July 1994. Shoot tissue was removed and stored at 4C for 136 days were with 16 g (0.89 kg·m-3) of 18–3–6 + and dried for weight determination. planted in a peat-based medium, Fafard Mg Osmocote Custom Blend (O.M. Tissue nutrient levels were measured no. 3B (Fafard, Anderson, S.C.). Two Scotts Co., Marysville, Ohio) and from the uppermost recently devel- planting depths were studied, 0.5 and grown outside. Irrigation was applied oped leaves which were weighed and 1 inch (1.25 and 2.5 cm). Seeds were using overhead sprinklers following included in the dry weight. given preplant treatments consisting normal nursery practice of 12.5 mm of of a control and 24-h soaks in distilled water per day. Results and discussion water, 100 ppm (mg·liter–1) gibberillic On 6 July 1994, the study was Seed Germination. Seeds soaked acid (GA4), and 7 mM and 14 mM terminated. Shoots and roots were in 100 ppm GA4 had the highest ger- thiourea. There were four replications collected and dried at 60C for 5 days mination percentages 21 days after of each seed treatment × planting depth and dry weight determination of both treatment (DAT) (Table 1). At 21 combination with five cells per repli- shoot and root tissue and root: shoot DAT the emerged seedlings from the cate. On 8 Feb 1994, before planting, ratio were determined. 100 ppm GA4 treatment were judged all seeds were disinfected by immers- Nutrition. Well rooted seed- to be most desirable. Seedlings from ing in 30% bleach solution for 30 rein, grown liners of Uniola paniculata were the 500 ppm GA4 treatment were and the medium was drenched with Banrot at 8 lb/100 gal (3.63 kg/5.8 Table 2. Shoot dry weight, root dry weight, and root/shoot ratio of Uniola paniculata grown liter). The seeds were planted in a 200- under different planting depths in a 4 pine bark: 1 sand (by volume) media. cell plug tray with two seeds per cell. The plug tray was placed under mist at an interval of 8 min for 8 sec. Bottom heat was provided at a constant tem- perature of 25C. The study was begun 9 Feb. 1994 and terminated 9 Mar. 1994. ‘Treatments analyzed using least significant difference (LSD) mean separation, Column means with the Planting depth. Well rooted same letter are not different based on P = 0.05.

296 HortTechnology. Oct./Dee, 1995 5(4) Table 3. Results of tissue analysisz and shoot dry weight of container-grown Uniola panicolata treated with various fertilizer formulations at standardized rates of 1.5 or 3 lb N/yd3 (0.89 or 1.78 kg N/m3) in a 4 pine bark: 1 sand (by volume) media.

zResults expressed as percentage for macronutrients (N, P, K, Ca, Mg) and ppm for micronutrients (Fe, Mn, Cu, Zn). yThe control was not topdressed with additional fertilizer, however did receive the normal nursery practice of twice weekly fertilizer-injected irrigation which -l -l -l contained 1.28 mol·liter Mg(NO 3)•2H2O, 3.80 mol·liter KNO3, and 0.96 mol·liter K 2HPO4 x Treatments analyzed using mean separation. Column means w ith M the same letter are not different based on P = 0.05 using least significant difference (LSD). twisted, caused by excessive cell elon- containers had higher shoot weights high N rates for each formulation gation (Taiz and Zeiger, 1991 ). Scari- than plants grown deep in 3.8-liter (Table 3). As N rate increased to 3 lb/ fied seeds were observed to have had containers. Root dry weights also were yd3, however the amount of shoot swelling equivalent to treatments that affected by planting depth, the plants biomass decreased for all three fertil- received soaking treatments only; how- grown deep had the lowest root izer formulations. The micronutrient- ever, scarification was not necessary to weights. Root to shoot ratios were only treatment also resulted in lower promote germination and resulted in similar between the planting depths. shoot weight. Hester and Mendelssohn germination no better than the con- However, plants grown in the 3.8-liter (1990) also found that micronutri- trol. containers, regardless of planting ents, either alone or in combination In the follow-up study there was depth, had root/shoot ratios almost with macro nutrients, had negatively no difference in the germination rates twice as high as the plants grown in the correlated effects on growth param- of any of the treatments (data not 9.2-liter containers. eters of U. paniculata. In our study shown). The germination rate of the Although the root/shoot ratios doubling the rate of fertilizer applica-

100 ppm GA4 soak was lower than of the plants grown in 3.8-liter con- tion not only increased the amount of previously observed. Thiourea did not tainers were similar, there were differ- macronutrients but also the micronu- improve the germination percentage, ences in the weights of the dried shoot trients, if treatment was a complete although it has been used effectively and root. The reason for these differ- formulation. by other researchers to stimulate ger- ences can be related back to the plant- mination of seeds that require a moist- ing depth. Plants grown in the bottom Conclusions chilling treatment (Hartmann and of these containers are exposed to a Uniola paniculata has the poten- Kester, 1983). Westra and Loomis perched water table or zone of media tial to become a widely grown nursery (1966) reported thiourea had no ef- saturation. The media in containers plant in the Southeast. Seeds should fect on germination in petri dishes, but remains wet under a regime of regular be planted soon after harvest in the fall at 7 mM thiourea dramatically increased irrigation such as would be followed in to ensure highest germination per-

Uniola seed germination in sand. a commercial nursery in the Southeast. centages of these seeds. A GA4 pre- Westra and Loomis ( 1966) found Hester and Mendelssohn (1989) found plant soak of the seeds will help more that as storage time increased germi- that seaoats growing in a natural dune rapid and uniform germination. The nation decreased, showing either in- setting and also under controlled ex- longer harvested seeds are held in stor- creased dormancy or decreased viabil- perimentation reacted adversely to age, decreased viability lowers germi- ity and that storage time is an impor- waterlogging stress. In experiments in nation efficiency. tant consideration. Soaking in 100 ppm which the root zones were placed at Typically on the dunes, the crowns

GA4 increased and accelerated germi- decreasing heights above the water of U. paniculata become buried by nation of freshly harvested seed, and as table, Hester and Mendelssohn ( 1989) drifting sand, however, burying the storage time increased, germination demonstrated that excessive soil mois- crown of U. paniculata in 3.8-liter rate was reduced. Our data supports ture resulted in reduced biomass pro- containers reduced the shoot and root the use of a GA4 soak. It appears that duction. However, decreasing soil weight of the plant due to the in- Uniola paniculata has a short span of moisture did not stimulate increased creased moisture in the bottom of the seed viability in storage and that seed growth. containers. Reducing the frequency dormancy was not the cause of poor Nutrition. Levels of tissue nu- and amount of irrigation would be germination. trients were similar were similar in helpful in encouraging maximum Planting depth. Planting depth many cases (Table 3). However, there growth. did have a significant influence on were significant effects on shoot dry Finally, U. paniculata does not shoot growth (Table 2). Plants grown weights due to fertilizer rate. The con- respond like most plants grown in with the crown even with the media trol treatment and the low N rates had containers to increased nutrient in- surface in 3.8-liter or deep in 9.2-liter higher shoot weights compared to the puts. High fertilization rates, whether

HortTechnology . Oct./Dec. 1995 5(4) 297 granular or controlled release, dramatically reduced the shoot weight of the plant. Nutrient inputs should be maintained at a minimum. The results of these experiments suggest that, through proper manage- ment, U. paniculata potentially could be a successful crop for nurseries to grow.

Literature Cited ColoSi, J. C. 1979. Seed germination as a function of provenance in Iva imbricata and Uniola paniculata, two wide-ranging coastal dune dominants. PhD diss. N.C. State Univ. Hartmann, H. T. and D.E. Kester. 1983. Techniques of propagation by seeds, p. 177. In: Plant propagation principles and practices. 4th ed. Prentice-Hall, Englewood Cliffs, N.J. Hester, M. W. and I.A. Mendelssohn. 1989. Water relations and growth responses of Uniola paniculata (sea oats) to soil moisture and water-table depth. Oecologia 78:289-296. Hester, M. W. and I.A. Mendelssohn. 1990. Effects of macronutrient and micronutrient additions on photosynthesis, growth parameters, and leaf nutrient concentra- tions of Uniola paniculata and Panicun amarum. Bot. Gaz. 151(1):21–29. Taiz, L. and E. Zeiger. 1991. Plant physiol- ow. 1st ed. Benjamin/Cummings Pub lishing Co., Redwood City, Calif. Wagner, R.H. 1964. The ecology of Uniola paniculata L. in the dune-strand habitat of North Carolina. Ecol. Monogr. 34:79-96. Westra, R.N. and W.L. Loomis. 1966. Seed dormancy in Uniola paniculata. Amer. J. Bet. 53(4):407-411. Wright, R.D. and A.X. Niemiera. 1987. Nutrition of container-grown woody nursery crops. Hort. Rev. 9:75–101 .p Woodhouse, W. W., Jr., and R.E. Hanes. 1966. Dune stabilization and vegetation on the Outer Banks of North Carolina. Soil Sci. Ser. 8. N.C. State Univ., Raleigh.

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