Propagation and Establishment of Perennial Peanuts for Ground Covers Along Roadsides and Highway Ramps

Proc. Fla. State Hort. Soc. 115:267-272. 2002. PROPAGATION AND ESTABLISHMENT OF PERENNIAL PEANUTS FOR GROUND COVERS ALONG ROADSIDES AND HIGHWAY RAMPS

AREF A. ABDUL-BAKI1 lished (Argel, 1994; de la Cruz et al., 1994). The extensive Sustainable Agricultural Systems Laboratory research on the accessions resulted in the release of three cul- ARS,USDA tivars of A. glabrata: ‘Arb’ in 1964 (Blickensderfer et al., 1964); Beltsville, MD 20705 ‘Florigraze’ in 1978 (Prine et al., 1981); and ‘Arbook’ in 1985 (Prine et al., 1986). Additionally, the A. pintoi cultivars, ‘Ama- HERBERT H. BRYAN, WALDEMAR KLASSEN rillo’ and ‘Porvenir’, were released in Australia in 1987 (Cook AND MAHARANIE CODALLO et al., 1990) and Latin America in 1997 (Argel and Villarreal, University of Florida 1998), respectively. Progress in the use of Arachis spp in live- Tropical Research and Education Center stock production has been reviewed for Latin America (Las- Homestead, FL 33031 cano, 1994; Pizarro and Rincon, 1994), Central America and Mexico (Argel, 1994), Asia, Africa and the Pacific (Stür and Additional index words. Arachis pintoi, forage peanuts, rooted Ndikumana, 1994), and the United States (French et al., plugs, turf mats 1994; Sollenberger et al., 1989). The Arachis spp. have several attractive traits that have not been adequately explored in the U.S. other than for forage Abstract. Some perennial peanut (Arachis pintoi) cultivars and accessions have the potential for use as ground covers along production. On the other hand, A. pintoi has been used in roadsides and highway ramps in regions with mild winters. many areas of Costa Rica and Columbia for the protection of They tolerate drought conditions, grow well in sandy and cal- steep roadside slopes and as an ornamental in home gardens careous soils of low fertility, fix N, recycle nutrients, prevent and parks (Lascano, personal communication). For example, soil erosion through a thick above-ground cover and an inten- the prolific production, attractive flowers, and the ability to sive root system, produce beautiful flowers, remain green all tolerate shaded environments while out-competing most year round, and do not require any mowing or fertilizer. Avail- weed species are important properties for cultivars/acces- ability of propagation material has been a limiting factor in ex- sions to be grown in shaded parks and along roadsides. Good panding their use, especially on a large scale. We describe a growth potential under shaded conditions is also important practical method for producing two types of propagation material - rooted plugs and mats. We further describe the planting for use as ground covers in tree orchards. A. pintoi cv ‘Amaril- and establishment of Arachis pintoi, cv. ‘Amarillo’, and acces- lo’ and IRFL 4222 have attractive flowers and grow well in sion No. IRFL 7154 as a roadside demonstration in a residen- shaded areas (Cook et al., 1990). The bright yellow flowers of tial area of North Miami, Fla. This demonstration provides ‘Amarillo’ and IRFL 7154 emerge above a dense green foliar evidence of the great potential and attractiveness of this spe- mat, resulting in a more attractive ground cover than grass for cies as a ground cover along roadsides and highway ramps in roadsides and highway ramps. Additional advantages over southern Florida. Rooted plugs are less costly to produce and grass ground covers include good growth potential on low fer- transport than mats. On the other hand, it takes less time and tility calcareous soils, an ability to fix their own nitrogen, management to get an established stand from mats than from drought tolerance, and, few requirements for mowing. This rooted plugs. last property greatly reduces maintenance cost and makes the Arachis spp. a truly sustainable ground cover (Rouse and Mul- The rhizomatous perennial peanut species Arachis glabra- lahey, 1997). ta Benth (Section Rhizomatosae) and the stoloniferous spe- Three main factors have limited the expansion of peren- cies Arachis pintoi Krapovickas and W. C. Gregory (section nial Arachis use: 1) inadequate sources of planting material Caulorrhizae) were introduced into Florida from Brazil in (vegetative propagation requires about 7 m3 of plant material 1932 (Blickensderfer et al., 1964) and in 1968 (National Ger- per ha), 2) inadequate mechanization to cut, dig and plant mplasm Resources on-line database, ARS/USDA), respective- the propagules, and 3) slow establishment rates, which may ly. Following introduction, they have been evaluated take up to three years (Valentim et al., 1987). Some measure extensively in Florida and the Gulf Coast region primarily for of weed control is usually required during the lengthy period hay production (Blickensderfer et al., 1964; Prine, 1980; Reed of establishment. Planting perennial peanut with a nurse and Ocumpaugh, 1991; Rich et al., 1995; Ruttinger, 1989; Va- crop, such as buckwheat or alfalfa, has proven to be highly lencia et al., 1999). The broad genetic base of the tested ac- beneficial (Anonymous 2001). cessions made it possible to select for desirable traits such as Also, maintaining the nurse crop at a 5 to 8-cm stubble high biomass production with elevated nutritive quality height reduces weed competition and stimulates lateral (French et al., 1994; Ruttinger, 1989), resistance to Meloidogy- spreading of the Arachis stolons. Some of the herbicides that ne arabicida (Dominguez et al., 1990) and M. exigua (Vallejos, have been used successfully include the application of glypho- 1992) nematodes, shade tolerance (Cook et al., 1990), ability sate ten days before planting A. pintoi stolons followed one to fix nitrogen, recycle nutrients, reduce soil erosion, and add month later with an application of Fluazifop-p-butyl or set- organic matter to the soil (Bryan et al., 2001). Arachis spp. re- hoxydim and light mowing at three months (de la Cruz et al., quire minimal management inputs once the stands are estab- 1994; Dwyer et al., 1989; Kretschmer, personal communication). In addition, Rouse and Mullahey (1997) reported effective grass control with Fluazifop-p-butyl, an important factor 1Corresponding author.

Proc. Fla. State Hort. Soc. 115: 2002. 267

in the establishment of the rhizoma peanut. Furthermore, M. J. Williams (personal communication) found that glyphosate provided selective weed suppression in rhizomatous perennial peanut cultivars. We report on a practical procedure for large-scale production of rooted plugs using stolon cuttings from A. pintoi, cv. ‘Amarillo’ and IRFL 7154, and on subsequent production of mats from rooted plugs. We further describe the planting and establishment of a roadside demonstration plot in a residential area of north Miami, Fla., as evidence of the great potential and attractiveness of this species as a ground cover along roadsides and highway ramps in southern Florida.

Materials and Methods

Source of plant material for propagation. ‘Amarillo’ and IRFL 7154 were two of the 16 cultivars/accessions of perennial Ara- chis obtained from the collection of Prof. Albert E. Fig. 2. Cuttings treated with Rhizobium at the rooting end and planted in Kretschmer, Jr., Indian River Research and Education Center, styrofoam trays using 3 cuttings per cell. University of Florida, Ft. Pierce, Fla. They were planted on 3 Mar. 1997, at the Tropical Research and Education Center (TREC), University of Florida, Homestead, to serve as plant trays were placed under a partially shaded frame over a layer material sources for further research. Each cultivar/accession of plastic mulch to prevent root growth into the soil below. An was planted in a 2.2 m × 9.5 m plot. Planting methods and sub- automated mist system maintained adequate moisture during sequent management throughout the establishment period the propagation period. Stolons developed a prolific root sys- are described in Bryan et al., 2001. Unrooted stolons from tem within 7 to 9 weeks and were ready to transplant into the ‘Amarillo’ and IRFL 7154 were the source of cuttings used in beds. Rooting under these conditions was about 80% (Fig. 3). these experiments for establishing a propagation procedure Production of mats from rooted plugs. The system we developed to produce mats from rooted plugs consisted of a series for the production of rooted plugs and mats as well as for es- × tablishing a demonstration plot on a roadside of a residential of flat 3.2 m 1.6 m beds with a 60-cm alleys between beds area in North Miami. They were chosen because of their vig- (Fig. 4). Iron rods (40-cm length, 2-cm diameter) were ham- orous growth, rapid establishment, dark-green, thick foliage, mered into the limestone substrate at the 4 corners of each and abundant yellow flowers (Kretschmer et al., 2001). bed. The bed floor was leveled and a strong string was secure- Production of rooted plugs. Stolon cuttings about 8 to 10 cm ly tied to the rods at a 10-cm height around the bed perime- long (2 to 3 nodes), with or without leaves, were taken from ter. Plastic mulch sheeting was laid within the bed, extending 3- month old stolons (Fig. 1). Generally a single stolon provid- up and over the string to form sidewalls with excess sheeting ed two adequate cuttings. The cuttings were first treated with tucked back under the floor plastic. Drainage was provided by cowpea ‘EL’ Rhizobium inoculant at the rooting zone to stim- several punctures to the plastic floor. This bed enclosure was ulate root growth, and then planted in styrofoam trays con- then filled with compost (West Palm Beach in-vessel co-com- taining Pro-Mix BX (Premier Horticulture Inc., Red Hill, PA post consisting by dry weight of 30% biosolids and 70% yard 18076). Each tray contained 72 cells, (4.5 × 4.5 × 8 cm). Three waste) to a depth of 9 cm, irrigated with an automated sprin- cuttings were planted in each cell (Fig. 2). The propagation kling system, and planted with six evenly spaced root plugs. The plastic floor and sides of the bed served two purposes: (1) they prevented weed propagules with the exception of nutsedges - from below and to the sides from invading the compost, and (2) they prevented the peanut roots from

Fig. 1. Cuttings taken from a fully developed stand for the production of Fig. 3. A tray of rooted plugs ready to transplant to produce mats. Insert rooted plugs. shows rooted plugs.

268 Proc. Fla. State Hort. Soc. 115: 2002.

but this treatment did not eradicate this weed. However, a few days after the weed had been sprayed, it became very weak, and could be removed easily by hand. The weeds that ap- peared to be most resistant to selective chemical control were beggarticks (Bidens spp.), prickly sida (Sida spinosa) and artil- leryweed (Pilea microphylla). ‘Amarillo’ and IRFL 7154 exhibited mild iron deficiency during the cool, short winter days. Some foliage turned light green to pale yellow during the cool, short-day months when photosynthesis and new foliage formation were slow. The deficiency was corrected with one drenching of Sequestrene® 138Fe (Ciba Geigy, Greensboro, NC) at 5 kg·4000 L-1/ha one month following transplanting into the beds. Once plant foliage achieved 100% bed coverage, the stur- dy network of stolons and roots was ready for harvest. The perennial peanut mats could be removed and used as Fig. 4. A nursery of 3.2 × 1.6-m plastic beds for production of mats. Note propagation material. A grass edger was used to cut through the major differences in growth rate (vigor), intensity of green leaf color and flower production across various A. pintoi cultivars/accessions. the thick stoloniferous mat and plastic floor. The plastic was included in the roll to assure maximum retention of the com- posts and rootlets. The 3.6 × 1.6-m bed was cut lengthwise into penetrating into the gravely soil, which would have caused five 3.2 × 0.3-m strips. These strips were then cut in half. Thus great damage to the roots upon removal of the mats. one bed generated ten 1.6 × 0.3-m mats. This convenient mat The beds for production of mats were arranged in a ran- dimension can be easily rolled and carried by one person domized complete block design with three replications. Ex- (Fig. 6). The 1.6 × 0.3-m mat comprised the standard propa- cellent establishment was achieved on all beds. The gation and transport unit for large-scale planting at target transplants grew rapidly and covered the whole bed area with- sites. During shipment and handling, these rolled mats held in 5 months. The stolons grew exponentially, branched pro- adequate amounts of water for several days. At the planting fusely, and initiated new roots. However, the tendency of the site, the mat was unrolled, further divided into forty 15 × 7 cm surface of the compost to dry rapidly prevented rooting. pieces, and these pieces were then planted at 70-cm within- Therefore a ca. 1.5 cm layer of topsoil was applied to the sur- row and 70-cm between row spacings. Watering and weed face of the compost, and thereafter rooting occurred. The ex- control were critically important during the first 6 weeks fol- tensive network of roots and stolons held the bedding media lowing planting to ensure successful establishment. in place. The new stolons resulted in a highly efficient stand A successful roadside demonstration. A demonstration plot capable of capturing solar radiation, fixing N, and producing was initiated to compare ‘Amarillo’ and IRFL 7154 with grass attractive flowers (Bryan et al., 2001) (Fig. 5). as ground covers along a roadside. The location was a center Weeds were controlled by means of herbicides supple- median strip (9.1-m long × 2.3-m wide) that had already been mented with hand weeding. Cadre (imazapyc) provided ex- planted into grass, at the entrance of a residential area at NW cellent control of both purple and yellow nutsedges. 102nd Avenue, 40 m south of NW 52nd Street, Miami, Florida Roundup was effective against many weed species, and Fluazi- (Fig. 7). Prior to this demonstration the grass received exten- fop-p-butyl was effective in killing grasses. Basagran (benta- sive management inputs including frequent watering, routine zon) damaged a significant percentage of dayflower plants, mowing, fertilization and herbicide application for weed con-

Fig. 5. A fully established ‘Amarillo’ bed displaying characteristically Fig. 6. An established ‘Amarillo’ bed cut into 3.2 × 0.3-m strips, rolled, and dense, green foliage and prolific flower production. transported for use as propagation material.

Proc. Fla. State Hort. Soc. 115: 2002. 269

received the same watering regime that was being applied to the grassy landscaping. Following planting on 28 Nov. 2000 until full establishment, the plot was mowed only once, and received no fertilizer and no other inputs other than water. In fact, the perennial peanut planting received much more water than necessary, since the irrigation regime was still target- ed for the surrounding grass-based landscaping. Within one year, the plot was fully established, providing an aesthetically attractive alternative to the traditional weed-infested grass stands typifying residential roadside median strips. Under perennial peanut, overall management costs were also reduced, since mowing and fertilizer inputs were not required.

Results and Discussion

The large-scale expansion of perennial peanut use in south Florida is severely constrained by the limited supply of propagation material. To address this constraint, strategies must be developed that will allow for the efficient vegetative production of rooted propagules on small and large scales. We were inspired to develop these propagation methods because it is very difficult to harvest seed or intact roots in the Krome gravelly loam soil in Miami-Dade County. However, since many Arachis species produce seed, for those with access to sandy soil it may be cheaper to produce seed than rooted plugs or mats for propagation (A. E. Kretschmer, Jr., pers. comm.). Our approach describes two options for the production of rooted propagules, rooted plugs and stolon mats. Both options are suitable for long-distance transport and marketing, Fig. 7. A demonstration plot of ‘Amarillo’ (front half) and IRFL 7154 without risk of drying or any other damage that would reduce (back half) planted in the street median of a residential area in North Miami, the quality and survival of the planting material. Once estab- Fla. Photo taken in early spring before full bloom. lished, the small plastic lined beds serve as a source of propagation material. Cuttings for rooted plug production can be made at any time during the year. Trays for rooted plugs trol. The objective of this demonstration was to show how pe- × × rennial peanut could both reduce roadside planting should have a cell size of 5 5 7 cm in order to maintain suf- maintenance and provide an aesthetically pleasing green ficient moisture for the development of a strong root system. ground cover with attractive yellow flowers. Clearly, these fac- Production cost is low since, in the subtropical climate of tors make perennial peanut a favorable alternative to grass for south Florida, supplementary heat and light are not needed. roadside landscaping. Participants in this demonstration plot Only a partially shaded area and an automated sprinkler sys- were the United States Department of Agriculture/Agricul- tem are needed. tural Research Service (represented by the senior author), Mat production is more costly and takes longer time to the University of Florida Tropical Research and Education prepare. Though the proposed flat beds for mat production Center, Homestead (represented by the junior authors), Mi- are simple to build, management requirements are higher, ami-Dade County Parks Department, South Florida Resource including irrigation, weed control, and harvest. Shipping Conservation and Development Council, and South Dade mats is more costly than shipping plugs on a hectare basis. On Soil and Water Conservation District. the other hand, mats provide extensive rooting material for One part of the strip (3.1-m long) was planted to ‘Amaril- large-scale planting. Furthermore, the stand gets established lo’; the rest (6.0-m long) was planted into IRFL 7154. This ac- faster, and competition by weeds is significantly less relative to cession performed well in our nursery at Homestead, and had stand establishment efforts with rooted plugs alone. excellent traits for use at roadsides similar to ‘Amarillo’. The One advantage of A. pintoi over A. glabrata is that it pro- grass was scraped to a depth of 10 cm, the soil was loosened, duces seed. However, the technical and economical feasibili- and then mixed with compost to provide good contact be- ties of propagating it by seed to protect roadsides have not tween the mat roots and the underlying soil. Using the previ- been explored. To our knowledge, the potential use of peren- ously described rolled mats, the perennial peanut was planted nial peanuts along roadsides and highway ramps in the U.S. as a 90-cm wide strip along the center of the median with has not been explored with A. pintoi despite the availability of roughly 60-cm wide unplanted borders on either side. The cultivars, and accessions that have the desirable traits. Peren- transplanted mats were pressed tight to encourage good con- nial peanuts offer many advantages over grass as ground cov- tact between the emergent roots and the underlying soil-com- ers. Once established, the extensive root system and thick post mixture. Additional compost was spread over the mats foliage cover of perennial peanut prevents soil erosion even and watered to cover the roots and keep them moist. During on the steep slopes that are typically encountered with high- the first few weeks after planting, the perennial peanut plants way ramps. Perennial peanuts have greatly reduced fertilizer requirements, since they fix nitrogen, and can efficiently re-

270 Proc. Fla. State Hort. Soc. 115: 2002.

cycle nutrients by storing essential nutrients in their large replications. Good establishment has been achieved in all the stoloniferous biomass (Bryan et al., 2001). These low growing plots. In summary, this paper presents two strategies for the legumes require almost no mowing and watering is rarely efficient propagation of perennial peanut plant material, that needed even under drought conditions. Above all, the peren- can be enlisted to improve the often neglected and unsightly nial peanut performs well in low fertility calcareous soils and appearance of public roadsides and highway ramps. can tolerate heavy traffic and wheel pressure by landscaping Acknowledgments. We acknowledge the very helpful sugges- equipment. These properties collectively reduce manage- tions from Drs. A. E. Kretschmer, C. E. Lascano, and R. Rice. ment costs, which ultimately make perennial peanut a sustainable ground cover with almost no maintenance Literature Cited requirements. In contrast to the low maintenance cost of perennial pea- Anonymous. 2001. Perennial peanut, Arachis pintoi. http://agrss.sher- nut, maintenance cost of grass along roadsides is high. In the man.hawaii.edu/onfarm/crop/crop0003.html. Argel, P. J. 1994. Regional experience with forage Arachis in Central America. year 2000-2001, Florida Department of Transportation spent p. 134-143. In P. C. Kerridge and B. Hardy (eds.). Biology and Agronomy 17.9 million dollars on mowing 297,010 ha of roadsides (Ta- of Forage Arachis. International Center for Tropical Agriculture. CIAT, ble 1). An additional 0.56 million dollars was spent on fertil- Cali, Columbia. izer. This brings the mowing and fertilizer cost to an average Argel, P. J. and M. Villarreal C. 1998. Nuevo mani forrajero perenne (Arachis of $62.15 per ha per year. It should be noted that the mainte- pintoi Krapovickas y Gregory) cultivar ‘Porvenir’ (CIAT 18744): Legumi- nosa herbacea para alimentacion animal, el mejoramiento y conservacion nance cost of sloped areas ($260.63 per ha) is about 6.9 times del suelo y el embellecimiento del paisaje. Ministerio de Agricultura y Ga- more than that of flat, open areas that utilize large-size mow- naderia de Costa Rica (MASG), Centro Internacional de Agricultura ers. Use of perennial peanut on these sloped ramps would sig- Tropical (CIAT). Boletin Tecnico. 32 p. nificantly reduce maintenance costs. Blickensderfer, C. B., H. J. Haynsworth, and R. D. Roush. 1964. Wild peanut is a promising forage legume for Florida. Crops Soils 17:19-20. On the aesthetic side, many perennial peanut accessions/ Bryan, H. H., A. Abdul-Baki, J. B. Reeves, III, L. M. Carrera, W. Klassen, G. cultivars such as ‘Amarillo’ and IRFL 7154 routinely produce Zinati, and M. Codallo. 2001. Perennial Arachis spp. as a multipurpose liv- a prolific and attractive stand of yellow flowers set against a ing mulch, ground cover and forage. J. Veg. Crop Production 7:113-136. pleasing green background that persists year-round (Figs. 4 Cook, B. G., R. J. Williams, and G. P. M. Wilson. 1990. Register of Australian and 5). In an established stand, the leaf surface area routinely herbage plant cultivars. B. Legumes. 21. Arachis (a) Arachis pintoi Krap. et Greg. nom. nud. (Pinto peanut) cv. ‘Amarillo’. Aust. J. Exp. Agric. 30:445- exceeds the soil surface area by a factor of 15 or more. This 446. high-density biomass efficiently captures light energy, which, de la Cruz, R., S. Suarez, and. E. Ferguson. 1994. The contribution of Arachis in turn, is used to produce organic matter food reserves for pintoi as a ground cover in some farming systems of tropical America. p. the plant. Over time the high-N leaf litter will serve to enrich 102-108. In P. C. Kerridge and B. Hardy (eds.). Biology and Agronomy of Forage Arachis. International Center for Tropical Agriculture, CIAT, Cali, the sandy or calcareous soils prevalent in south Florida. Columbia. The demonstration plot established in north Miami high- Dominguez, J. A., N. Marban, and R. de la Cruz. 1990. Leguminosas de lights an important niche that can be successfully addressed coberuaras associadas con tomate var. Dina Guabayo y su efecto sobre Me- by A. pintoi perennial peanuts, namely, sustainable, low-main- loidogyne arabicida Lopez y Salazar. Turrialba 40:217-221. tenance attractive landscaping for use on roadsides and high- Dwyer, G. T., P. J. O’Hare, and B. J. Cook. 1989. Pinto’s peanut: A ground cover for orchards. Queensl. Agric. J. 6:153-154. way ramps. Currently there are millions of hectares of park French, E. C., G. M. Prine, W. R. Ocumpaugh, and R. W. Rice. 1994. Regional areas, roadsides and highway ramps throughout the southern experience with forage Arachis in the United States. p. 169-186. In P. C. and Gulf Coast USA that can be planted to this ground cover. Kerridge and B. Hardy (eds.). Biology and Agronomy of Forage Arachis. Replacing these currently grass/weed-based systems with pe- International Center for Tropical Agriculture, CIAT, Cali, Columbia. Kretschmer, A. E., Jr., T. C. Wilson, R. S. Kalmbacher, R. N. Pittman, and J.W. rennial peanut will effectively reduce maintenance costs. It Hebb, Jr. 2001. Evaluation of growth, yield, flowering and nut production also would save the Parks Services and the Highways Adminis- of a group of wild, nut-producing peanuts in south Florida. Soil Crop Sci. trations millions of dollars, and would provide the local pop- Soc. Fla. Proc. 60:105-113. ulace a more aesthetically pleasing landscape on roadsides Lascano, C. E. 1994. Nutritive value and animal production of forage Arachis and highway ramps. Reproducibility of establishment was sub- species. p. 109- 20 In P. C. Kerridge and B. Hardy (eds.). Biology and Agronomy of Forage Arachis. International Center for Tropical Agricul- stantiated in a separate study (data not shown) initiated in ture, CIAT, Cali, Columbia. Aug. 2001 in which the two accessions were established be- National Germplasm Resources Laboratory on-line database, Germplasm Re- tween trees in five rows in an Annona grove at TREC. The lat- sources Information Network, ARS, USDA, Beltsville, MD indicates that ter experiment is a randomized complete block with five Arachis pintoi was first received in Nov. 1968 as P. I. 338314 from a collection in Cruz das Almas, Brazil. Pizarro, E. A. and A. Rincon. 1994. Regional experience with forage Arachis in South America. p. 144-157. In P. C. Kerridge and B. Hardy (eds.). Biol- ogy and Agronomy of Forage Arachis. International Center for Tropical Table 1. Roadside mowing cost for the state of Florida during the year Agriculture, CIAT, Cali, Columbia. 2000-2001. Prine, G. M. 1980. Growing perennial peanuts for rhizomes. Agron. Res. Re- port AY 80-6, Dept. of Agronomy, Agr. Exp. Sta., IFAS, Univ. of Florida, Area Cost/ha Total cost Gainesville, Fla. Mower size (ha) $ million $ Prine, G. M., L. S. Dunavin, R. J. Glennon, and R. D. Roush. 1986. ‘Arbook’ rhizoma peanut: A potential forage legume. Fla. Agric. Exp. Sta. Circ. S- Large machine mowing 257,618 38.04 9.8 332. Intermediate machine mowing 10,256 126.76 1.3 Prine, G. M. L. S. Dunavin, J. E. Moore, and R. D. Roush. 1981. ‘Florigraze’ Small machine mowing 16,858 213.55 3.6 rhizoma peanut, a perennial forage legume. Univ. of Florida Agric. Exp. Slope mowing 12,278 260.63 3.2 Stn., Gainesville, Fla. Circ. S-332 297,010 60.27 17.9 Reed, R. L. and W. R. Ocumpaugh. 1991. Screening rhizoma peanut for ad- Total for mowing aptation to calcareous soils. J. Plant Nutr. 14:163-174. Fertilizer 1.89 0.56 Rich, J. R., G. S. Rahi, E. C. French, and C. B. Olson. 1995. Status of perennial peanut production in north Florida. Soil Crop Sci. Soc. Fla. Proc. 54:41- Source: J. Allen and K. McCrary, Department of Transportation, Florida 43.

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Rouse, R. E. and J. J. Mullahey. 1997. Perennial peanut ground cover in citrus Kerridge and B. Hardy (eds.). Biology and Agronomy of Forage Arachis. orchard middles and discussion of potential environmental benefits. International Center for Tropical Agriculture, CIAT, Cali, Columbia. Proc. Fla. State Hort. Soc. 110:70-81. Valentim, J. F., O. C. Ruelke, and G. M. Prine. 1987. Interplanting of alfalfa Ruttinger, A. E. 1989. Evaluation of perennial Arachis germplasm for agro- and rhizoma peanut. Soil Crop Sci. Soc. Fla. Proc. 46:52-55. nomic performance, response to root-knot nematode, and three peanut Valencia, E., M. J. Williams, and L. E. Sollenberger. 1999. Yield and botanical leaf spot diseases. M.S. Thesis. University of Florida, Gainesville, Fla. composition of rhizoma peanut-grass swards treated with herbicides. Sollenberger, L. E., C. S. Jones, and G. M. Prine. 1989. Animal performance Agronomy J. 91:956-961. on dwarf elephant grass and rhizoma peanut pastures. XVI International Vallejos, R. M. 1992. Coberturas vivas en la cultivo de café (Coffea arabica), su Grassland Congress, Nice, France. pp. 1189-1190. establecimiento y relacyon con malezas y Meloidogyne exigua. M.S. Thesis. Stür, W. W. and J. Ndikumana. 1994. Regional experience with forage Arachis Centro Agronomica Tropical de Investigacion y Encenanza (CATIE), in other tropical areas: Asia, Africa, and the Pacific. p. 187-198. In P. C. Turrialba, Costa Rica. 64p.

Proc. Fla. State Hort. Soc. 115:272-275. 2002. RATING LANDSCAPE TREES: LESSONS LEARNED FROM AN EXPERT SURVEY

ALFREDO B. LORENZO1 expert opinions and the associated difficulties and problems Florida A&M University others might encounter going through a similar undertaking in Landscape Design and Management Program Florida. This study also examines the degree of agreement Tallahassee, FL 32307 among the professional groups in the rating of species listed for Louisiana by the International Society Arboriculture (ISA).

CATALINO A. BLANCHE Trees have become widely recognized as important com- USDA/CSREES- NRE ponent of urbanized and developing landscapes. Urban land- Washington, DC 20250 scape trees are also called amenity trees because they produce a variety of tangible and intangible benefits for urban dwell- JAMES F. HENSON ers and have monetary value. The need to know the monetary Southern University and A&M College value of landscape trees is no longer limited to real estate USDA/NRCS/ National Plant Data Center transactions, lawsuits, insurance claims, tax purposes but also Baton Rouge, LA 70813 for tree inventories and tree care investment decisions. The most common and widely used method for establish- EDWIN R. DUKE ing the value of large trees is through the use of formulas. In Florida A & M University the United States, several formulas and methods of determin- Ornamental Horticulture Program ing the monetary value of landscape trees have been devel- Tallahassee, FL 32307 oped over the years. These formulas and methods are described in the 8th edition of the Guide for Plant Appraisal by Additional index words. landscape trees, tree value, trunk-for- the Council of Tree and Landscape Appraisers (CTLA). mula method These formulas are each a function of four primary factors, namely, size, species, condition and location factors. The Abstract. The monetary value of landscape trees is needed for most widely used of these formulas is the trunk formula meth- various purposes including tree inventories, real estate trans- od for trees too large to be physically replaceable. Using the actions, lawsuits, insurance claims, tax purposes, and tree formula requires the determination of a species rating value care investment decisions. Several formulas and methods based solely upon species characteristics. Watson (2000) com- have been developed to determine these values. The most pared the trunk formula method with other formulas, and widely used method, the trunk formula method, requires a spe- concluded that the major differences in appraised values us- cies rating value for the tree being appraised. Pooling judg- ing the trunk formula are attributed to species rating value. ments and opinions of tree experts, such as foresters, horticulturists, landscape architects, nurserymen and ar- Tree appraisers, arborists, foresters, and other plant pro- borists, is a widely used procedure to derive species rating fessionals have been using species values that came with the value. Due to differences in training and background of tree Guide. These species rating values were subjectively assigned by professionals, and the wide variability of landscapes in any a group of experts in 1970 (Lewis, 1970). The current species given area, professional agreement on the rating of a species rating values are in five categories of 20% class intervals. The is difficult to reach, but yet, necessary to be useful. This study Guide classifies trees according to species and varieties, varying describes our experiences in developing species rating values according to different geographical areas in the country. for Louisiana trees using the traditional technique of pooling The problem with the system of species rating by pooling experts is that it gives a wide range of values to every species. This translates to very divergent appraisals by two or more 1Corresponding author. plant/tree professionals of a tree in question. Experiment sta-

272 Proc. Fla. State Hort. Soc. 115: 2002.