Proc. Fla. State Hort. Soc.

115: 2002. 267

Proc. Fla. State Hort. Soc

. 115:267-272. 2002.

PROPAGATION AND ESTABLISHMENT OF PERENNIALPEANUTS FOR GROUND COVERS ALONG ROADSIDES AND HIGHWAY RAMPS

A

REF

A. A

BDUL

-B

AKI

1

Sustainable Agricultural Systems LaboratoryARS,USDA

Beltsville, MD 20705

H

ERBERT

H. B

RYAN

, W

ALDEMAR

K

LASSENAND

M

AHARANIE

C

ODALLO

University of FloridaTropical Research and Education Center

Homestead, FL 33031

Additional index words

.

Arachis pintoi

, forage peanuts, rootedplugs, turf mats

Abstract.

Some perennial peanut (

Arachis pintoi)

cultivars andaccessions have the potential for use as ground covers alongroadsides and highway ramps in regions with mild winters.They tolerate drought conditions, grow well in sandy and cal-careous soils of low fertility, fix N, recycle nutrients, preventsoil erosion through a thick above-ground cover and an inten-sive root system, produce beautiful flowers, remain green allyear round, and do not require any mowing or fertilizer. Avail-ability of propagation material has been a limiting factor in ex-panding their use, especially on a large scale. We describe apractical method for producing two types of propagation ma-terial - rooted plugs and mats. We further describe the plantingand establishment of

Arachis pintoi

, cv. ‘Amarillo’, and acces-sion No. IRFL 7154 as a roadside demonstration in a residen-tial area of North Miami, Fla. This demonstration providesevidence of the great potential and attractiveness of this spe-cies as a ground cover along roadsides and highway ramps insouthern Florida. Rooted plugs are less costly to produce andtransport than mats. On the other hand, it takes less time andmanagement to get an established stand from mats than fromrooted plugs.

The rhizomatous perennial peanut species

Arachis glabra-ta

Benth (Section Rhizomatosae) and the stoloniferous spe-cies

Arachis pintoi

Krapovickas and W. C. Gregory (sectionCaulorrhizae) were introduced into Florida from Brazil in1932 (Blickensderfer et al., 1964) and in 1968 (National Ger-mplasm Resources on-line database, ARS/USDA), respective-ly. Following introduction, they have been evaluatedextensively in Florida and the Gulf Coast region primarily forhay production (Blickensderfer et al., 1964; Prine, 1980; Reedand Ocumpaugh, 1991; Rich et al., 1995; Ruttinger, 1989; Va-lencia et al., 1999). The broad genetic base of the tested ac-cessions made it possible to select for desirable traits such ashigh biomass production with elevated nutritive quality(French et al., 1994; Ruttinger, 1989), resistance to

Meloidogy-ne arabicida

(Dominguez et al., 1990) and

M. exigua

(Vallejos,1992) nematodes, shade tolerance (Cook et al., 1990), abilityto fix nitrogen, recycle nutrients, reduce soil erosion, and addorganic matter to the soil (Bryan et al., 2001).

Arachis

spp. re-quire minimal management inputs once the stands are estab-

1

Corresponding author.

lished (Argel, 1994; de la Cruz et al., 1994). The extensiveresearch on the accessions resulted in the release of three cul-tivars of

A. glabrata

: ‘Arb’ in 1964 (Blickensderfer et al., 1964);‘Florigraze’ in 1978 (Prine et al., 1981); and ‘Arbook’ in 1985(Prine et al., 1986). Additionally, the

A. pintoi

cultivars, ‘Ama-rillo’ and ‘Porvenir’, were released in Australia in 1987 (Cooket al., 1990) and Latin America in 1997 (Argel and Villarreal,1998), respectively. Progress in the use of

Arachis

spp in live-stock production has been reviewed for Latin America (Las-cano, 1994; Pizarro and Rincon, 1994), Central America andMexico (Argel, 1994), Asia, Africa and the Pacific (Stür andNdikumana, 1994), and the United States (French et al.,1994; Sollenberger et al., 1989).

The

Arachis

spp. have several attractive traits that have notbeen adequately explored in the U.S. other than for forageproduction. On the other hand,

A. pintoi

has been used inmany areas of Costa Rica and Columbia for the protection ofsteep roadside slopes and as an ornamental in home gardensand parks (Lascano, personal communication). For example,the prolific production, attractive flowers, and the ability totolerate shaded environments while out-competing mostweed species are important properties for cultivars/acces-sions to be grown in shaded parks and along roadsides. Goodgrowth potential under shaded conditions is also importantfor use as ground covers in tree orchards.

A. pintoi

cv ‘Amaril-lo’ and IRFL 4222 have attractive flowers and grow well inshaded areas (Cook et al., 1990). The bright yellow flowers of‘Amarillo’ and IRFL 7154 emerge above a dense green foliarmat, resulting in a more attractive ground cover than grass forroadsides and highway ramps. Additional advantages overgrass ground covers include good growth potential on low fer-tility calcareous soils, an ability to fix their own nitrogen,drought tolerance, and, few requirements for mowing. Thislast property greatly reduces maintenance cost and makes the

Arachis

spp. a truly sustainable ground cover (Rouse and Mul-lahey, 1997).

Three main factors have limited the expansion of peren-nial

Arachis

use: 1) inadequate sources of planting material(vegetative propagation requires about 7 m

3

of plant materialper ha), 2) inadequate mechanization to cut, dig and plantthe propagules, and 3) slow establishment rates, which maytake up to three years (Valentim et al., 1987). Some measureof weed control is usually required during the lengthy periodof establishment. Planting perennial peanut with a nursecrop, such as buckwheat or alfalfa, has proven to be highlybeneficial (Anonymous 2001).

Also, maintaining the nurse crop at a 5 to 8-cm stubbleheight reduces weed competition and stimulates lateralspreading of the

Arachis

stolons. Some of the herbicides thathave been used successfully include the application of glypho-sate ten days before planting

A. pintoi

stolons followed onemonth later with an application of Fluazifop-p-butyl or set-hoxydim and light mowing at three months (de la Cruz et al.,1994; Dwyer et al., 1989; Kretschmer, personal communica-tion). In addition, Rouse and Mullahey (1997) reported effec-tive grass control with Fluazifop-p-butyl, an important factor

268

Proc. Fla. State Hort. Soc.

115: 2002.

in the establishment of the rhizoma peanut. Furthermore, M.J. Williams (personal communication) found that glyphosateprovided selective weed suppression in rhizomatous perenni-al peanut cultivars.

We report on a practical procedure for large-scale pro-duction of rooted plugs using stolon cuttings from

A. pintoi

,cv. ‘Amarillo’ and IRFL 7154, and on subsequent productionof mats from rooted plugs. We further describe the plantingand establishment of a roadside demonstration plot in a resi-dential area of north Miami, Fla., as evidence of the great po-tential and attractiveness of this species as a ground coveralong roadsides and highway ramps in southern Florida.

Materials and Methods

Source of plant material for propagation

. ‘Amarillo’ and IRFL7154 were two of the 16 cultivars/accessions of perennial

Ara-chis

obtained from the collection of Prof. Albert E.Kretschmer, Jr., Indian River Research and Education Center,University of Florida, Ft. Pierce, Fla. They were planted on 3Mar. 1997, at the Tropical Research and Education Center(TREC), University of Florida, Homestead, to serve as plantmaterial sources for further research. Each cultivar/accessionwas planted in a 2.2 m

×

9.5 m plot. Planting methods and sub-sequent management throughout the establishment periodare described in Bryan et al., 2001. Unrooted stolons from‘Amarillo’ and IRFL 7154 were the source of cuttings used inthese experiments for establishing a propagation procedurefor the production of rooted plugs and mats as well as for es-tablishing a demonstration plot on a roadside of a residentialarea in North Miami. They were chosen because of their vig-orous growth, rapid establishment, dark-green, thick foliage,and abundant yellow flowers (Kretschmer et al., 2001).

Production of rooted plug

s. Stolon cuttings about 8 to 10 cmlong (2 to 3 nodes), with or without leaves, were taken from3- month old stolons (Fig. 1). Generally a single stolon provid-ed two adequate cuttings. The cuttings were first treated withcowpea ‘EL’ Rhizobium inoculant at the rooting zone to stim-ulate root growth, and then planted in styrofoam trays con-taining Pro-Mix BX (Premier Horticulture Inc., Red Hill, PA18076). Each tray contained 72 cells, (4.5

×

4.5

×

8 cm). Threecuttings were planted in each cell (Fig. 2). The propagation

trays were placed under a partially shaded frame over a layerof plastic mulch to prevent root growth into the soil below. Anautomated mist system maintained adequate moisture duringthe propagation period. Stolons developed a prolific root sys-tem within 7 to 9 weeks and were ready to transplant into thebeds. Rooting under these conditions was about 80% (Fig. 3).

Production of mats from rooted plugs

. The system we devel-oped to produce mats from rooted plugs consisted of a seriesof flat 3.2 m

×

1.6 m beds with a 60-cm alleys between beds(Fig. 4). Iron rods (40-cm length, 2-cm diameter) were ham-mered into the limestone substrate at the 4 corners of eachbed. The bed floor was leveled and a strong string was secure-ly tied to the rods at a 10-cm height around the bed perime-ter. Plastic mulch sheeting was laid within the bed, extendingup and over the string to form sidewalls with excess sheetingtucked back under the floor plastic. Drainage was provided byseveral punctures to the plastic floor. This bed enclosure wasthen filled with compost (West Palm Beach in-vessel co-com-post consisting by dry weight of 30% biosolids and 70% yardwaste) to a depth of 9 cm, irrigated with an automated sprin-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 nut-sedges - from below and to the sides from invading the com-post, and (2) they prevented the peanut roots from

Fig. 1. Cuttings taken from a fully developed stand for the production ofrooted plugs.

Fig. 2. Cuttings treated with Rhizobium at the rooting end and planted instyrofoam trays using 3 cuttings per cell.

Fig. 3. A tray of rooted plugs ready to transplant to produce mats. Insertshows rooted plugs.

Proc. Fla. State Hort. Soc.

115: 2002. 269

penetrating into the gravely soil, which would have causedgreat damage to the roots upon removal of the mats.

The beds for production of mats were arranged in a ran-domized complete block design with three replications. Ex-cellent establishment was achieved on all beds. Thetransplants grew rapidly and covered the whole bed area with-in 5 months. The stolons grew exponentially, branched pro-fusely, and initiated new roots. However, the tendency of thesurface of the compost to dry rapidly prevented rooting.Therefore a ca. 1.5 cm layer of topsoil was applied to the sur-face of the compost, and thereafter rooting occurred. The ex-tensive network of roots and stolons held the bedding mediain place. The new stolons resulted in a highly efficient standcapable of capturing solar radiation, fixing N, and producingattractive flowers (Bryan et al., 2001) (Fig. 5).

Weeds were controlled by means of herbicides supple-mented with hand weeding. Cadre (imazapyc) provided ex-cellent control of both purple and yellow nutsedges.Roundup was effective against many weed species, and Fluazi-fop-p-butyl was effective in killing grasses. Basagran (benta-zon) damaged a significant percentage of dayflower plants,

but this treatment did not eradicate this weed. However, a fewdays 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 werebeggarticks (

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 lightgreen to pale yellow during the cool, short-day months whenphotosynthesis and new foliage formation were slow. The de-ficiency was corrected with one drenching of Sequestrene®138Fe (Ciba Geigy, Greensboro, NC) at 5 kg·4000 L

-1

/ha onemonth 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 pe-rennial peanut mats could be removed and used aspropagation material. A grass edger was used to cut throughthe thick stoloniferous mat and plastic floor. The plastic wasincluded in the roll to assure maximum retention of the com-posts and rootlets. The 3.6

×

1.6-m bed was cut lengthwise intofive 3.2

×

0.3-m strips. These strips were then cut in half. Thusone bed generated ten 1.6

×

0.3-m mats. This convenient matdimension can be easily rolled and carried by one person(Fig. 6). The 1.6

×

0.3-m mat comprised the standard propa-gation and transport unit for large-scale planting at targetsites. During shipment and handling, these rolled mats heldadequate amounts of water for several days. At the plantingsite, the mat was unrolled, further divided into forty 15

×

7 cmpieces, and these pieces were then planted at 70-cm within-row and 70-cm between row spacings. Watering and weedcontrol were critically important during the first 6 weeks fol-lowing planting to ensure successful establishment.

A successful roadside demonstration

. A demonstration plotwas initiated to compare ‘Amarillo’ and IRFL 7154 with grassas ground covers along a roadside. The location was a centermedian strip (9.1-m long

×

2.3-m wide) that had already beenplanted into grass, at the entrance of a residential area at NW102nd Avenue, 40 m south of NW 52nd Street, Miami, Florida(Fig. 7). Prior to this demonstration the grass received exten-sive management inputs including frequent watering, routinemowing, fertilization and herbicide application for weed con-

Fig. 4. A nursery of 3.2 × 1.6-m plastic beds for production of mats. Notethe major differences in growth rate (vigor), intensity of green leaf color andflower production across various A. pintoi cultivars/accessions.

Fig. 5. A fully established ‘Amarillo’ bed displaying characteristicallydense, green foliage and prolific flower production.

Fig. 6. An established ‘Amarillo’ bed cut into 3.2 × 0.3-m strips, rolled, andtransported for use as propagation material.

270

Proc. Fla. State Hort. Soc.

115: 2002.

trol. The objective of this demonstration was to show how pe-rennial peanut could both reduce roadside plantingmaintenance and provide an aesthetically pleasing greenground cover with attractive yellow flowers. Clearly, these fac-tors make perennial peanut a favorable alternative to grass forroadside landscaping. Participants in this demonstration plotwere the United States Department of Agriculture/Agricul-tural Research Service (represented by the senior author),the University of Florida Tropical Research and EducationCenter, Homestead (represented by the junior authors), Mi-ami-Dade County Parks Department, South Florida ResourceConservation and Development Council, and South DadeSoil and Water Conservation District.

One part of the strip (3.1-m long) was planted to ‘Amaril-lo’; the rest (6.0-m long) was planted into IRFL 7154. This ac-cession performed well in our nursery at Homestead, and hadexcellent traits for use at roadsides similar to ‘Amarillo’. Thegrass was scraped to a depth of 10 cm, the soil was loosened,and then mixed with compost to provide good contact be-tween the mat roots and the underlying soil. Using the previ-ously described rolled mats, the perennial peanut was plantedas a 90-cm wide strip along the center of the median withroughly 60-cm wide unplanted borders on either side. Thetransplanted mats were pressed tight to encourage good con-tact between the emergent roots and the underlying soil-com-post mixture. Additional compost was spread over the matsand watered to cover the roots and keep them moist. Duringthe first few weeks after planting, the perennial peanut plants

received the same watering regime that was being applied tothe grassy landscaping. Following planting on 28 Nov. 2000until full establishment, the plot was mowed only once, andreceived no fertilizer and no other inputs other than water. Infact, the perennial peanut planting received much more wa-ter than necessary, since the irrigation regime was still target-ed for the surrounding grass-based landscaping. Within oneyear, the plot was fully established, providing an aestheticallyattractive alternative to the traditional weed-infested grassstands typifying residential roadside median strips. Under pe-rennial 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 insouth Florida is severely constrained by the limited supply ofpropagation material. To address this constraint, strategiesmust be developed that will allow for the efficient vegetativeproduction of rooted propagules on small and large scales.We were inspired to develop these propagation methods be-cause it is very difficult to harvest seed or intact roots in theKrome gravelly loam soil in Miami-Dade County. However,since many

Arachis

species produce seed, for those with accessto sandy soil it may be cheaper to produce seed than rootedplugs or mats for propagation (A. E. Kretschmer, Jr., pers.comm.).

Our approach describes two options for the production ofrooted propagules, rooted plugs and stolon mats. Both op-tions are suitable for long-distance transport and marketing,without risk of drying or any other damage that would reducethe quality and survival of the planting material. Once estab-lished, the small plastic lined beds serve as a source of propa-gation material. Cuttings for rooted plug production can bemade at any time during the year. Trays for rooted plugsshould have a cell size of 5

×

5

×

7 cm in order to maintain suf-ficient moisture for the development of a strong root system.Production cost is low since, in the subtropical climate ofsouth Florida, supplementary heat and light are not needed.Only a partially shaded area and an automated sprinkler sys-tem are needed.

Mat production is more costly and takes longer time toprepare. Though the proposed flat beds for mat productionare simple to build, management requirements are higher,including irrigation, weed control, and harvest. Shippingmats is more costly than shipping plugs on a hectare basis. Onthe other hand, mats provide extensive rooting material forlarge-scale planting. Furthermore, the stand gets establishedfaster, and competition by weeds is significantly less relative tostand establishment efforts with rooted plugs alone.

One advantage of

A. pintoi

over

A. glabrata

is that it pro-duces seed. However, the technical and economical feasibili-ties of propagating it by seed to protect roadsides have notbeen explored. To our knowledge, the potential use of peren-nial peanuts along roadsides and highway ramps in the U.S.has not been explored with

A. pintoi

despite the availability ofcultivars, and accessions that have the desirable traits. Peren-nial peanuts offer many advantages over grass as ground cov-ers. Once established, the extensive root system and thickfoliage cover of perennial peanut prevents soil erosion evenon the steep slopes that are typically encountered with high-way ramps. Perennial peanuts have greatly reduced fertilizerrequirements, since they fix nitrogen, and can efficiently re-

Fig. 7. A demonstration plot of ‘Amarillo’ (front half) and IRFL 7154(back half) planted in the street median of a residential area in North Miami,Fla. Photo taken in early spring before full bloom.

Proc. Fla. State Hort. Soc.

115: 2002. 271

cycle nutrients by storing essential nutrients in their largestoloniferous biomass (Bryan et al., 2001). These low growinglegumes require almost no mowing and watering is rarelyneeded even under drought conditions. Above all, the peren-nial peanut performs well in low fertility calcareous soils andcan tolerate heavy traffic and wheel pressure by landscapingequipment. These properties collectively reduce manage-ment costs, which ultimately make perennial peanut a sustain-able ground cover with almost no maintenancerequirements.

In contrast to the low maintenance cost of perennial pea-nut, maintenance cost of grass along roadsides is high. In theyear 2000-2001, Florida Department of Transportation spent17.9 million dollars on mowing 297,010 ha of roadsides (Ta-ble 1). An additional 0.56 million dollars was spent on fertil-izer. This brings the mowing and fertilizer cost to an averageof $62.15 per ha

per year. It should be noted that the mainte-nance cost of sloped areas ($260.63 per ha) is about 6.9 timesmore than that of flat, open areas that utilize large-size mow-ers. Use of perennial peanut on these sloped ramps would sig-nificantly reduce maintenance costs.

On the aesthetic side, many perennial peanut accessions/cultivars such as ‘Amarillo’ and IRFL 7154 routinely producea prolific and attractive stand of yellow flowers set against apleasing green background that persists year-round (Figs. 4and 5). In an established stand, the leaf surface area routinelyexceeds the soil surface area by a factor of 15 or more. Thishigh-density biomass efficiently captures light energy, which,in turn, is used to produce organic matter food reserves forthe plant. Over time the high-N leaf litter will serve to enrichthe sandy or calcareous soils prevalent in south Florida.

The demonstration plot established in north Miami high-lights an important niche that can be successfully addressedby

A. pintoi

perennial peanuts, namely, sustainable, low-main-tenance attractive landscaping for use on roadsides and high-way ramps. Currently there are millions of hectares of parkareas, roadsides and highway ramps throughout the southernand Gulf Coast USA that can be planted to this ground cover.Replacing these currently grass/weed-based systems with pe-rennial peanut will effectively reduce maintenance costs. Italso would save the Parks Services and the Highways Adminis-trations millions of dollars, and would provide the local pop-ulace a more aesthetically pleasing landscape on roadsidesand highway ramps. Reproducibility of establishment was sub-stantiated in a separate study (data not shown) initiated inAug. 2001 in which the two accessions were established be-tween trees in five rows in an Annona grove at TREC. The lat-ter experiment is a randomized complete block with five

replications. Good establishment has been achieved in all theplots. In summary, this paper presents two strategies for theefficient propagation of perennial peanut plant material, thatcan be enlisted to improve the often neglected and unsightlyappearance of public roadsides and highway ramps.

Acknowledgments

. We acknowledge the very helpful sugges-tions from Drs. A. E. Kretschmer, C. E. Lascano, and R. Rice.

Literature Cited

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Arachis pintoi.

http://agrss.sher-man.hawaii.edu/onfarm/crop/crop0003.html.

Argel, P. J. 1994. Regional experience with forage

Arachis

in Central America.p. 134-143. In P. C. Kerridge and B. Hardy (eds.). Biology and Agronomyof Forage

Arachis

. International Center for Tropical Agriculture. CIAT,Cali, Columbia.

Argel, P. J. and M. Villarreal C. 1998. Nuevo mani forrajero perenne (Arachispintoi Krapovickas y Gregory) cultivar ‘Porvenir’ (CIAT 18744): Legumi-nosa herbacea para alimentacion animal, el mejoramiento y conservaciondel suelo y el embellecimiento del paisaje. Ministerio de Agricultura y Ga-naderia de Costa Rica (MASG), Centro Internacional de AgriculturaTropical (CIAT). Boletin Tecnico. 32 p.

Blickensderfer, C. B., H. J. Haynsworth, and R. D. Roush. 1964. Wild peanutis a promising forage legume for Florida. Crops Soils 17:19-20.

Bryan, H. H., A. Abdul-Baki, J. B. Reeves, III, L. M. Carrera, W. Klassen, G.Zinati, and M. Codallo. 2001. Perennial

Arachis

spp. as a multipurpose liv-ing mulch, ground cover and forage. J. Veg. Crop Production 7:113-136.

Cook, B. G., R. J. Williams, and G. P. M. Wilson. 1990. Register of Australianherbage plant cultivars. B. Legumes. 21.

Arachis

(a)

Arachis pintoi

Krap. etGreg.

nom. nud.

(Pinto peanut) cv. ‘Amarillo’. Aust. J. Exp. Agric. 30:445-446.

de la Cruz, R., S. Suarez, and. E. Ferguson. 1994. The contribution of

Arachispintoi

as a ground cover in some farming systems of tropical America. p.102-108. In P. C. Kerridge and B. Hardy (eds.). Biology and Agronomy ofForage

Arachis

. International Center for Tropical Agriculture, CIAT, Cali,Columbia.

Dominguez, J. A., N. Marban, and R. de la Cruz. 1990. Leguminosas decoberuaras associadas con tomate var. Dina Guabayo y su efecto sobre

Me-loidogyne arabicida

Lopez y Salazar. Turrialba 40:217-221.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.French, E. C., G. M. Prine, W. R. Ocumpaugh, and R. W. Rice. 1994. Regional

experience with forage

Arachis

in the United States. p. 169-186. In P. C.Kerridge and B. Hardy (eds.). Biology and Agronomy of Forage

Arachis

.International Center for Tropical Agriculture, CIAT, Cali, Columbia.

Kretschmer, A. E., Jr., T. C. Wilson, R. S. Kalmbacher, R. N. Pittman, and J.W.Hebb, Jr. 2001. Evaluation of growth, yield, flowering and nut productionof a group of wild, nut-producing peanuts in south Florida. Soil Crop Sci.Soc. Fla. Proc. 60:105-113.

Lascano, C. E. 1994. Nutritive value and animal production of forage

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species. p. 109- 20 In P. C. Kerridge and B. Hardy (eds.). Biology andAgronomy of Forage

Arachis

. International Center for Tropical Agricul-ture, CIAT, Cali, Columbia.

National Germplasm Resources Laboratory on-line database, Germplasm Re-sources Information Network, ARS, USDA, Beltsville, MD indicates that

Arachis pintoi

was first received in Nov. 1968 as P. I. 338314 from a collec-tion in Cruz das Almas, Brazil.

Pizarro, E. A. and A. Rincon. 1994. Regional experience with forage

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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,Gainesville, Fla.

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-332.

Prine, G. M. L. S. Dunavin, J. E. Moore, and R. D. Roush. 1981. ‘Florigraze’rhizoma peanut, a perennial forage legume. Univ. of Florida Agric. Exp.Stn., Gainesville, Fla. Circ. S-332

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Rich, J. R., G. S. Rahi, E. C. French, and C. B. Olson. 1995. Status of perennialpeanut production in north Florida. Soil Crop Sci. Soc. Fla. Proc. 54:41-43.

Table 1. Roadside mowing cost for the state of Florida during the year2000-2001.

Mower sizeArea(ha)

Cost/ha$

Total costmillion $

Large machine mowing 257,618 38.04 9.8Intermediate machine mowing 10,256 126.76 1.3Small machine mowing 16,858 213.55 3.6Slope mowing 12,278 260.63 3.2

Total for mowing 297,010 60.27 17.9

Fertilizer 1.89 0.56

Source: J. Allen and K. McCrary, Department of Transportation, Florida

272

Proc. Fla. State Hort. Soc.

115: 2002.

Rouse, R. E. and J. J. Mullahey. 1997. Perennial peanut ground cover in citrusorchard middles and discussion of potential environmental benefits.Proc. Fla. State Hort. Soc. 110:70-81.

Ruttinger, A. E. 1989. Evaluation of perennial

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germplasm for agro-nomic performance, response to root-knot nematode, and three peanutleaf spot diseases. M.S. Thesis. University of Florida, Gainesville, Fla.

Sollenberger, L. E., C. S. Jones, and G. M. Prine. 1989. Animal performanceon dwarf elephant grass and rhizoma peanut pastures. XVI InternationalGrassland Congress, Nice, France. pp. 1189-1190.

Stür, W. W. and J. Ndikumana. 1994. Regional experience with forage

Arachis

in other tropical areas: Asia, Africa, and the Pacific. p. 187-198. In P. C.

Kerridge and B. Hardy (eds.). Biology and Agronomy of Forage

Arachis

.International Center for Tropical Agriculture, CIAT, Cali, Columbia.

Valentim, J. F., O. C. Ruelke, and G. M. Prine. 1987. Interplanting of alfalfaand rhizoma peanut. Soil Crop Sci. Soc. Fla. Proc. 46:52-55.

Valencia, E., M. J. Williams, and L. E. Sollenberger. 1999. Yield and botanicalcomposition of rhizoma peanut-grass swards treated with herbicides.Agronomy J. 91:956-961.

Vallejos, R. M. 1992. Coberturas vivas en la cultivo de café (

Coffea arabica

), suestablecimiento y relacyon con malezas y

Meloidogyne exigua

. M.S. Thesis.Centro Agronomica Tropical de Investigacion y Encenanza (CATIE),Turrialba, Costa Rica. 64p.

Proc. Fla. State Hort. Soc

. 115:272-275. 2002.

RATING LANDSCAPE TREES: LESSONS LEARNED FROM AN EXPERT SURVEY

A

LFREDO

B. L

ORENZO

1

Florida A&M UniversityLandscape Design and Management Program

Tallahassee, FL 32307

C

ATALINO

A. B

LANCHE

USDA/CSREES- NREWashington, DC 20250

J

AMES

F. H

ENSON

Southern University and A&M CollegeUSDA/NRCS/ National Plant Data Center

Baton Rouge, LA 70813

E

DWIN

R. D

UKE

Florida A & M UniversityOrnamental Horticulture Program

Tallahassee, FL 32307

Additional index words.

landscape trees, tree value, trunk-for-mula method

Abstract.

The monetary value of landscape trees is needed forvarious purposes including tree inventories, real estate trans-actions, lawsuits, insurance claims, tax purposes, and treecare investment decisions. Several formulas and methodshave been developed to determine these values. The mostwidely used method, the trunk formula method, requires a spe-cies rating value for the tree being appraised. Pooling judg-ments and opinions of tree experts, such as foresters,horticulturists, landscape architects, nurserymen and ar-borists, is a widely used procedure to derive species ratingvalue. Due to differences in training and background of treeprofessionals, and the wide variability of landscapes in anygiven area, professional agreement on the rating of a speciesis difficult to reach, but yet, necessary to be useful. This studydescribes our experiences in developing species rating valuesfor Louisiana trees using the traditional technique of pooling

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Corresponding author.

expert opinions and the associated difficulties and problemsothers might encounter going through a similar undertaking inFlorida. This study also examines the degree of agreementamong the professional groups in the rating of species listedfor Louisiana by the International Society Arboriculture (ISA).

Trees have become widely recognized as important com-ponent of urbanized and developing landscapes. Urban land-scape trees are also called amenity trees because they producea variety of tangible and intangible benefits for urban dwell-ers and have monetary value. The need to know the monetaryvalue of landscape trees is no longer limited to real estatetransactions, lawsuits, insurance claims, tax purposes but alsofor tree inventories and tree care investment decisions.

The most common and widely used method for establish-ing the value of large trees is through the use of formulas. Inthe United States, several formulas and methods of determin-ing the monetary value of landscape trees have been devel-oped over the years. These formulas and methods aredescribed in the 8th edition of the

Guide for Plant Appraisal

bythe Council of Tree and Landscape Appraisers (CTLA).These formulas are each a function of four primary factors,namely, size, species, condition and location factors. Themost widely used of these formulas is the trunk formula meth-od for trees too large to be physically replaceable. Using theformula requires the determination of a species rating valuebased solely upon species characteristics. Watson (2000) com-pared the trunk formula method with other formulas, andconcluded that the major differences in appraised values us-ing the trunk formula are attributed to species rating value.

Tree appraisers, arborists, foresters, and other plant pro-fessionals have been using species values that came with the

Guide

. These species rating values were subjectively assigned bya group of experts in 1970 (Lewis, 1970). The current speciesrating values are in five categories of 20% class intervals. The

Guide

classifies trees according to species and varieties, varyingaccording to different geographical areas in the country.

The problem with the system of species rating by poolingexperts is that it gives a wide range of values to every species.This translates to very divergent appraisals by two or moreplant/tree professionals of a tree in question. Experiment sta-