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site maintained by the Florida Cooperative Extension Service.
Copyright 2005, Board of Trustees, University of Florida
3Ciu- -o 75 C ircu la S-275
'FL ORIGRAZE' RHIZOMA PEANUT A Perennial Forage Legume
G. M. Prine, L. S. J. E. Moore and R.
Coter. Main scene: Coverage of Florigraze rhizoma peanut in
May, 1978 following establishment by placing rhizome mats 1 foot square (930 cm') in hills 6 feet apart in every direction on March 4, 1977. Inset: Closeup of Florigraze
'FLORIGRAZE' RHIZOMA PEANUT
A Perennial Forage Legume
G. M. Prine, L. S. Dunavin, J. E. Moore and R. D. Roush
This publication was printed in cooperation with the USDA Soil Conservation Service
This public document was promulgated at an annual cost of $2,723.30 or a cost of 54.5r per copy to inform Florida Extension personnel, ranchers, and forage producers of research
results and potential uses of Florigraze rhizoma peanut.
Dr. G. M. Prine is Professor, Agronomy Department, University of Florida, Gainesville. Dr. L. S. Dunavin is Associate Professor of Agronomy, IFAS Agricultural Research Center at Jay. Dr. J. E. Moore is Professor, Animal Science Department, University of Florida, Gainesville. R. D. Roush is Manager, SCS, Plant Materials Center, Brooksville, Florida.
Introduction 1 O rig in 1 D escription 1 E stablishm ent 2 Forage Y ields 9 Hay Digestibility and Protein Content 10 M anagem ent for Hay 15 Dehydrated Products 15 Grazing M anagem ent 16 W inter M anagem ent 17 Fertilization and Liming Established Rhizoma Peanuts 17 P ests 19 Ornam ental U ses 19 C over Crop 20 W eediness 20 Planting M aterial 21 References 22
Trade names of products, where given, are used for the purpose of providing specific information. Use of a commercial name is not intended as an endorsement of products named, nor as criticism of similar products not named.
'Florigraze' rhizoma peanut (Arachis glabrata Benth.) is a warmseason perennial forage legume having value as both a hay and grazing crop. Florigraze can be grown alone or in a mixture with perennial summer grasses, and promises to fulfill the need for a persistent, high quality perennial legume on the well-drained soils of Florida. The rhizoma peanut is a new crop to both farmers and researchers, so many of the details in managing the crop are incomplete at present.
Florigraze peanut was first observed by G. M. Prine when a rapidly spreading peanut plant appeared in the spring of 1962 between year-old plots of 'Arb' (PI 118457) and PI 151982 rhizoma peanuts on the main Agronomy Farm at Gainesville. When it appeared that the plant was different from plants in either adjacent plot, vegetative material was collected and established in a separate plot. This peanut was tested as Gainesville Selection No. 1. (GS-1) until named Florigraze. We suspect that Florigraze is a seedling from Arb; the Arb material was collected by W. Archer near Campo Grande, Brazil in 1936 (10).
Rhizoma peanut is the common name given perennial members in section Rhizomatosae of the peanut genus Arachis which have underground stems or rhizomes. Florigraze has rhizomes and is a long-lived perennial of the species glabrata, one of the 30 to 50 species in the genus Arachis (6). Most of these species are perennial, but several species are annuals, including the common peanut (A. hypogaea L.). The origin of A. glabrata is in South America, where this species is reported from about 8' to 350 south latitude (7). Naturally occurring stands of glabrata and other wild species of the genus Arachis form an important part of the herbage supporting vast herds of cattle in South America. The Soil Conservation Service (SCS), Plant Materials Center at Brooksville, Florida has named and distributed to farmers for testing several introductions of rhizoma peanut. Small acreages of two
of these cultivars, Arb (2) and 'Arblick' (PI 262839), are now growing in the state.
Florigraze peanut is finer stemmed and has narrower leaflets on the quadrifoliate leaves than Arb or Arblick. The rhizome diameter of Florigraze is smaller and usually has a greater number of rhizomes per unit area of soil. A rhizomateous mat of Florigraze (Figure 1) has more budding points and develops more shoots per unit of soil surface than a similar sized mat of Arb or Arblick. Florigraze and Arb flowers are yellow-orange, whereas Arblick flowers are creamy-yellow. Florigraze usually does not flower as profusely as Arb or Arblick. Seeds develop very rarely on these three rhizoma peanuts.
Florigraze is adapted to well-drained soils but not to "flatwoods soils"or to any soil which is subject to high water tables. It grows most rapidly during the warm, moist periods of the year, even though some growth will occur during any long frost-free period. A new planting of Florigraze peanuts survived a winter at the SCS Plant Materials Center near Americus, Georgia when temperatures dropped as low as 3'F (-14'C) (13). Florigraze peanuts can survive low temperatures because of their rhizome system which grows several inches below the soil surface; however, with a long cold season, forage production will be too low for practical use. The potential yield of rhizoma peanuts is greater in the longer warm season of South Florida than in North Florida. Florigraze production in the Continental United States will be limited to Florida and warmer portions of other southernmost states.
Once established, Florigraze is quite drought resistant. If drought is severe, the top growth may completely die and then regenerate from rhizomes following rainfall. During shorter drought periods, top growth is slow, but recovery is rapid after adequate rainfall occurs. Around the world, Florigraze peanut should be productive on well-drained soils in humid tropical and subtropical areas.
Florigraze can be planted in moderately-well to extremely welldrained soils of all textures. Peanuts, to be dug for rhizomes, should only be planted on sandy soils without rocks or high clay content which interfere with digging. Coverage of Florigraze is often slow on eroded clay subsoils, apparently due to inability of rhizomes to penetrate the dense soil.
Soils should be tested before planting rhizoma peanuts, and lime and fertilizer should be applied and incorporated into soil prior to planting. If soil test recommendations are not available, 300 pounds
per acre (336 kg/ha) of 0-10-20 (N-P205-K20) fertilizer before planting and 300 pounds per acre of the same fertilizer in early August of the establishment season is recommended. Sulfur and minor elements should also be applied prior to planting on most soils. A soil pH range of 5.8 to 6.5, usually suggested for the common peanut, appears to be satisfactory for rhizoma peanuts. Soil CaO and MgO should be at least 750 and 100 pounds/acre (840 and 112 kg/ha), respectively.
Shoots of Florigraze cut at late hay stage and planted in soil under field conditions rarely survive, so Florigraze needs to be propagated from rhizomes. We have used modified potato diggers to lift most of our Florigraze rhizomes (Figures 2 and 3). Some peanut diggers might also be modified to do this job satisfactorily.
Recently a bermudagrass sprig digger was used to dig Florigraze rhizomes (Figure 4). There was some rhizome loss in harvesting, but most rhizome pieces lived after planting and put up one or more shoots. Because the sprig digger tears rhizomes into short pieces, usually less than 12 inches (30 cm), the amount of area covered per rhizome piece may be small in the planting year. It is possible that with more experience this machine can be adapted to digging peanut rhizomes.
To harvest rhizomes with the modified potato digger, the rhizome mass is first cut into square or rectangular mats or long ribbons with gangs of rolling coulters. Then the digger lifts and shakes soil from the rhizomes and deposits them on top of the soil. Mat squares smaller than 12 inches (30 cm) on a side are difficult to dig. Rhizomes dig easiest when cut in long narrow ribbons in the direction of digging. They should not be allowed to stand for long periods in sunlight, but should be collected into loosely packed piles and shaded.
Planting Material and Spacing Needed
The quantity of rhizome material needed per hill is large for Florigraze peanuts. A square foot (930 cm2) or more of rhizome mat should be planted in each hill when sufficient plant material is available. Rhizome mats one foot square or larger can be planted in hills up to six feet (1.8 m) apart in every direction. However it is best to gently separate the mat into four pieces and plant in hills 3 feet (0.9 m) apart. Using either method, one acre (0.4 hectare) of wellestablished Florigraze can plant 36 acres (14.4 hectares). This
Figure 1. Rhizomateous mat piece from a well-established stand of Florigraze rhizoma peanut.
Figure 2. Digging Florigraze peanut rhizomes with one-row potato digger.
Figure 3. Digging Florigraze peanut rhizomes with a two-row potato
Figure 4. Digging Florigraze peanut rhizomes with a bermudagrass sprig
assumes that all of the original acre is dug for rhizomes and cut into 1 square foot (30 x 30 cm) mats and each mat is distributed over 36 square feet (3.4 M2) of soil. Rhizomes will probably be sold by volume. To have a planting rate similar to the preceding example, it will take 25 to 40 bushels (0.9 to 1.4 m3) of rhizomes per acre (0.4 ha), depending upon the size of rhizomes. The smaller the diameters of rhizomes, the lower the planting rate needed per acre or hectare.
In the early years following the release of Florigraze, it will be necessary to plant the maximum acreage with the minimum amount of rhizomes. This can be done by dividing the rhizome mat into individual pieces about 12 inches (30 cm) long and planting one rhizome piece per hill. This should only be done on land without any perennial grass and with excellent weed control. Complete coverage the first year will generally not occur with this method of planting. Hills should be no further than 36 inches (91 cm) apart in any direction. Using this method, 6 to 10 bushels (0.2 to 0.35 m:) of rhizomes will be needed to plant 1 acre (0.4 ha).
Time to Plant
Florigraze should be planted during the winter months (December, January, February, and early March), when the top growth is either dead or dormant. The rhizomes are more resistant to drying out then than during the warm season, and soil moisture need not be optimum. Florigraze planted during winter spreads from rhizomes which develop in late summer and fall of the planting year. If planting is delayed until the summer, limited new rhizome development occurs the first fall and little spread occurs until the second year. Winter-planted Florigraze develops a good root system, and first-season plantings have survived long spring droughts. When weeds are palatable, it is possible to rotationally graze them down during the first season; however, grazing also removes peanut top growth and limits first season coverage. No grazing should take place until the peanuts are over 4 inches (10 cm) tall. Livestock should be removed as soon as weeds are eaten down. Livestock should not be left on peanuts longer than 10 days in each grazing cycle the first season, and a rest period of at least 6 weeks should occur before grazing again.
Rhizoma Peanut-Grass Mixtures
The seed or vegetative material of a grass can be planted between the peanut rows during the summer following winter planting. However, care should be taken to avoid disturbing the peanut plants
in planting grass. Nitrogen fertilizer should not be applied to grass on soils where grass will survive without. On other soils, small amounts of N up to 30 pounds per acre (33.6 kg/ha) could be applied to grass but not close to the peanuts. The ideal practice is to keep the grass alive with minimum competition for the peanut until the peanut is established and furnishing nitrogen for the grass.
The planting of Florigraze in established perennial grass sods is not recommended, as competition from the grass delays establishment. However, if the perennial grass sod is plowed under in the fall and disced twice at several week intervals prior to planting Florigraze, the grass will usually recover enough during the summer to make a satisfactory mixture with the peanut. In this situation, it is very important not to apply any nitrogenous fertilizer. It is also desirable to plant Florigraze hills close together (not over 3 feet (91 cm) apart) in anticipation of reduced spread of the peanut the first season.
In mid-April 1976, two rows 36 inches (91 cm) apart of corn, soybeans, sorghum, southern peas, and peanuts were planted between rows 9 ft. (2.7 m) apart of Florigraze established the last week of February, 1976. In the spring of 1977, the Florigraze development was as good where crops were grown as on the control area where no crops were planted. However, the Florigraze spread about 2V2 feet (76 cm) to each side of the rows from original hills, so a large strip in middle between peanut rows was not covered by peanut at the end of the first season. Growing of row crops in middles between Florigraze peanut rows offers economic return during the establishment year. Research is continuing to see if crops can be grown between narrower rows of Florigraze during the first establishment year.
The rhizomes should be planted as soon as possible after digging for the strongest development of new plants; however, loosely packed rhizomes have sprouted satisfactorily after storing under a tarpaulin for 7 days in winter, with occasional wetting to prevent drying out.
Planting requires several steps. The first is to prepare a furrow wide and deep enough to accept the rhizome piece or mat and to allow for complete coverage with 2 or 3 inches (5 to 7.5 cm) of soil in heavy soils and 3 to 32 inches (7.5 to 9 cm) in sandy soils. When the
rhizome is placed in the furrow, a granular or liquid peanut inoculant should be applied either under or over the rhizome mat and quickly covered with soil. Ideally, all these planting steps will be done with a planter which will open the furrow, apply inoculant, place rhizome mat, and cover in one operation.
Rhizomes dug with a bermudagrass sprig digger can be planted with the bermudagrass sprig planter. In a preliminary study, planting rhizomes in 20 inch (51 cm) rows at rate of 40 bushels (1.4 m3) of rhizomes per acre (0.4 ha) with the sprig planter was successful in giving good first season coverage where weeds were controlled.
Weed control is essential during the first season, if maximum coverage from the planting is to be obtained. Where spacing of rows permits, it may be desirable to cultivate between peanut rows. Care must be taken not to hit peanut plants with cultivation equipment, as this breaks off the developing new roots and loosens the rhizome mat in the soil. No cultivation should be made after July of the planting year, as the new rhizomes beginning to develop from the peanut hills may be damaged.
I Research indicates that most herbicides which are effective and recommended for common peanut will also be useful for weed control in establishing and maintaining rhizoma peanuts. Particularly helpful to establishment of Florigraze has been the pre-plant incorporation of benefin (BALAN), trifluralin (TREFLAN), vernolate (VERNAM), and tank-mixtures of benefin and vernolate and trifluralin and vernolate herbicides. A tank-mixture of alachlor (LASSO) and dinoseb (PREMERGE) applied at first emergence of rhizoma peanut shoots in spring has controlled both winter weeds and spring weeds. Bentazon (BASAGRAN) and 2,4 DB have been applied over top of rhizoma peanut throughout the growing season. Because rhizoma peanut is a new crop starting off with low acreage no herbicides have been labeled for specific use on rhizoma peanut.
Hopefully this situation will be rectified in the future so that herbicides can be legally used on rhizoma peanut. Once a herbicide is approved for use on rhizoma peanut, one should read the label carefully to see limitations on use of forage for grazing, silage, or hay.
Normally some weeds become established and may shade the developing peanut hills. When this happens, mow the tall weeds just above the peanut canopy with a mower. Do not remove any peanut top growth if you expect maximum coverage by the end of the first season.
When Florigraze was first planted in 1962, it established more rapidly than other rhizoma peanut selections planted at the same time. In 1965, Florigraze peanut was planted in a nursery with Arb and Arblick and a number of other rhizoma peanut introductions. The most productive of these are listed in Table 1. By the spring of 1967, the Florigraze plots were superior in coverage to all other rhizoma peanuts. The nursery plots were harvested twice a year for hay for four years beginning in 1967 (Table 1). During the first two harvest seasons the Florigraze plots were quite superior in hay yields to other accessions (Table 1). The more rapid establishment of Florigraze was a factor in this early superiority. During the last two seasons, Florigraze yields were equal to or better than the other peanut cultivars and accessions. Over the four-year period, the hay yield of Florigraze averaged 0.7 tons per acre (1570 kg/ha) per year greater than the next closest peanut cultivar or introduction.
In May 1966, another cultivar trial comparing Arb, Arblick, and Florigraze was planted at Gainesville. Because of the slow establishment of Arb and Arblick, no hay cuttings were made until 1970,
Table 1. Hay yields of rhizoma peanut cultivars and accessions at Gainesville over 4 growing seasons during 1967 to 1971.
Dry Matter Yield
or P.1. 4-year
Number 1967 1968 1970 1971 average
-------------------------tons/acrej --------------------------Florigrazet 3.2 5.9 5.2 4.1 4.6 A*
Arbt 2.1 4.1 5.3 4.2 3.9 B
Arblickt .6 2.1 3.3 3.3 2.3 C
262794 1.8 3.4 5.4 3.3 3.5
262818 1.0 3.4 3.7 4.3 3.1
262819 1.7 3.5 3.9 2.6 3.0
262828 1.5 3.3 3.8 3.0 2.9
262832 2.1 3.1 3.2 3.0 2.9
262840 1.0 3.2 5.2 3.9 3.3
Overall average 1.7 3.6 4.4 3.5 3.4
Data in this table were taken from Prine (11).
Averages of replicated cultivars not marked with same large letter are significantly different at the .05 level.
t Data for these accessions are averages of duplicate plots. Other yields are for
$ To convert tons per acre (tons/A) to metric tons per hectare (t/ha), multiply by
though Florigraze plots could have been cut for hay in 1968. A 'Pensacola' bahiagrass sod had been plowed under prior to planting. Consequently the bahiagrass volunteered from seed and vegetative sprouts and formed a mixture with the peanuts. The Florigraze peanut produced the highest hay yield each season and also had highest content of legume in hay (Table 2). The rapid establishment of Florigraze was associated with a reduced number of bahiagrass plants surviving on these plots. All peanut cultivars eventually dominated over the bahiagrass in the mixture. The yields of individual cuttings of hay for three harvests in each of the years 1974 and 1975 are presented in Table 3.
In 1970, Florigraze was planted with Arb and Arblick at the Jay Agricultural Research Center and at the SCS Plant Materials Center at Brooksville. Hay yields and other data for Florigraze compared with Arb and Arblick at Jay are presented in Table 4 and at Brooksville in Table 5. Florigraze was superior to Arb and Arblick at both locations.
Table 2. The hay yields of three rhizoma peanut cultivars growing in mixture with Pensacola bahiagrass on Kanapha fine sand at Gainesville, Florida during 5 growing seasons.
Pensacola bahiagrass Growing Season 5-Season
in mixture with 1970 1972 1973 1974 1975 Average
------------ dry matter yield (tons/A)t ---------------Florigraze 4.7 a* 3.2 a 5.5 a 5.3 a 5.0 a 4.7 A*
Arb 3.4 b 2.5 c 3.2 c 3.7 b 4.2 b 3.4 B
Arblick 3.6 b 2.8 b 3.8 b 3.7 b 4.8 ab 3.8 B
---------- estimated % peanut forage in hay --------Florigraze 90 90 90 90 90 90
Arb 25 60 60 80 70 60
Arblick 25 70 55 65 80 60
Cuttings per season 2 2 2 3 3
* Season and 5-season yield averages not marked with same letter are significantly
different at the .05 level.
t To convert tons per acre to metric tons per hectare (t/ha), multiply tons/A by 2.24.
HAY DIGESTIBILITY AND PROTEIN CONTENT
Florigraze was higher than Arb and Arblick in percent in vitro organic matter digestion (IVOMD) and percent protein over a fouryear period at Gainesville (Table 6). Florigraze forage was also
Table 3. Production of hay, protein content, and in vitro digestion of three rhizoma peanuts
bahiagrass for different cuttings over a two-year period at Gainesville, Florida.
in mixture with Pensacola
Cultivar June 20 Aug 12 Oct 20 Season total June 18 Aug 22 Oct 14 Season total
harvest harvest harvest harvest harvest harvest
---------------------------------dry matter yieldt (lb/A)t ---------------------------------------Florigraze 4210 4160 2050 10420 a* 4560 3930 1510 10,000 a*
Arb 2580 3370 1540 7490 b 3210 3710 1410 8330 b
Arblick 2840 3450 1160 7450 b 3880 3170 1610 8660 ab
Bahiagrass only 1000 590 580 2170 c 750 970 360 2080 c
-----------------------------------------------% crude proteint ----------------------------Florigraze 15.8 18.2 19.1 12.4 12.2 18.3
Arb 15.2 15.6 17.7 12.1 11.3 15.2
Arblick 15.7 15.3 12.8 11.1 9.8 14.0
Bahiagrass only 7.9 10.0 12.5 9.0 7.7 11.5
---------------------% IVOMDt- ------------------------------Florigraze 66.7 63.7 71.7 56.1 57.1 67.1
Arb 63.2 55.4 67.8 54.5 53.9 64.2
Arblick 62.0 56.7 59.6 59.9 52.7 57.2
Bahiagrass only 47.4 45.9 51.2 41.5 43.1 42.2
This experiment was fertilized annually in March with 500 pounds per acre of 0-10-20 (N-P20- K20) fertilizer. No extra N was applied to
bahiagrass only plots.
t Dry matter yields are the mean of 6 replications, while % crude protein and % IVOMD (% of organic matter in sample digested) are the mean
of 3 of the 6 replications.
t To convert lb/A to kg/ha, multiply lb/A by 1.12.
Season total values for the same measurement not marked by the same letter are significantly different at the .05 level.
Table 4. The dry matter yield, protein content, and in vitro digestion of
three rhizoma peanut cultivars at Jay Agricultural Research Center over five growing seasons.
Growing Season 5-Season
1972 1973 1974 1975 1976
--------------dry matter hay yield (tons/A)t--------Florigraze 3.0 2.6 3.8 3.8 4.0 3.4
Arb 1.2 0.9 1.4 1.4 0.9 1.2
Arblick 1.3 1.2 1.9 2.5 2.7 1.9
-----------------------% crude protein --------------Florigraze 16.4 13.3 14.0 14.6
Arb 11.2 8.9 10.3 10.1
Arblick 14.7 13.3 10.8 12.9
-------------------------% IVOMD- ----------------Florigraze 69.2 64.4 66.1 66.6
Arb 62.4 58.0 59.9 60.1
Arblick 64.2 64.5 62.2 63.7
This experiment was planted in August 1970 and was cut twice annually as hay. t To convert tons per acre (tons/A) to metric tons per hectare (t/ha), multiply tons/A
T % IVOMD = % of organic matter in sample which was digested.
Table 5. Hay yield of three rhizoma peanut cultivars at the SCS Plant
Materials Center at Brooksville for three years.
Dry Matter Yield
Cultivarst 1973 1974 1975 3-year
------------------------- tons/acret -------------Florigraze 4.0 2.0 2.5 2.8
Arblick 2.5 2.8 2.3 2.5
Arb 2.6 2.4 1.8 2.3
t Peanuts were planted July 31 and August 1,1969, and were all well established at
initiation of harvesting. Fertilizer rate was 1000 lb/A (1120 kg/ha) of 0-10-20
fertilizer annually in split application.
$ To convert tons per acre (tons/A) to metric tons per hectare (t/ha) multiply tons/A
Table 6. The average annual organic matter digestibility and protein and
mineral contents of hay from three rhizoma peanut cultivars over
four seasons at Gainesville, Florida.
Constituent unit Arb Arblick Florigraze
IVOMD % 60.8 57.0 62.2
Digestible OM produced lb/A 3860 2230 4390
Protein content % 12.8 13.5 14.0
Protein produced lb/A 1000 630 1290
N content % 2.05 2.16 2.24
N in hay lb/A 160 100 206
P content % .30 .29 .28
P in hay lb/A 24 14 26
K content % 2.17 2.13 1.74
K in hay lb/A 180 110 125
Ca content % 1.42 1.34 1.52
Ca in hay lb/A 115 66 131
Mg content % .35 .29 .47
Mg in hay lb/A 30 15 43
Data in this table were taken from Prine (11). Average seasonal hay yields of each
cultivar cut twice annually during each of 4 seasons is given in Table 1.
To convert lb/A to kg/ha, multiply lb/A by 1.12.
higher than Arb and Arblick forage in percentage IVOMD and protein during the three seasons at Jay ARC (Table 4) and for all three cuttings during two seasons at Gainesville (Table 3).
The protein content of Florigraze hay has ranged from 12% to 19%, and IVOMD percentages from 55% to 72% in hay cut after six weeks or more of regrowth. When IVOMD values have been below 60%, it was traceable to extremely mature peanut plants and/or to peanuts being in mixture with mature grass or weeds. Young perennial peanut forage, such as would be available to grazing animals, should be even higher in protein and IVOMD percentage than was found for hay.
Florigraze and 'Florunner' (common) peanut hays were chopped and fed to sheep for the determination of quality in terms of voluntary intake and digestion (Table 7). These hays were made after 60 days or more of regrowth, because it requires at least this long for Florigraze to become tall enough to cut for hay using conventional machinery. Digestion of organic matter (OM) was relatively high in all peanut hays in both years and compared favorably with that of younger 'Florida 66' alfalfa hay in previous trials.
Voluntary intakes of Florigraze hays were high enough to suggest no problems with palatability. Even though Florigraze hays
Table 7. Organic matter digestibility and intake of total digestible organic
matter by sheep fed alfalfa and common and rhizoma peanut hays.
Body Organic Matter
Hays Digestibility Intake
lb % -------- (g/d)/kgt -----1975 season
(60 days old) 88 66.8 66.9 46.9
(over 4 months old) 84 62.1 57.9 35.9
cut July 25
Florunner common peanut (108 days after seeding) 90 68.5 75.3 51.6
Florunner common peanut (mature seed stage 130
days after seeding) 93 69.7 74.9 52.2
(cut July 1, 62 days old) 95 68.2 89.4 61.0
(cut September 9, 70
days old) 95 64.9 82.5 53.6
Florida 66 alfalfat
4.5 weeks old 63.7 70.4 81.6 90.7 53.6 60.5
6 weeks old 62.5 68.1 86.0 87.7 46.7 58.0
t Data on alfalfa taken from Tiharuhondi (14).
1 Grams of organic matter per day for metabolic body weight in kilograms.
had a lower intake than Florunner hays in the 1975 trial, the intake of digested OM (an estimate of Total Digestible Nutrients) was well above the maintenance requirement. Excellent intakes were recorded for 1976 Florigraze hays with digestible OM intakes equal to 1.8 to 2.0 times the maintenance requirement. These digested OM intake values compare favorably to those of 4.5 week-old Florida 66 alfalfa (1.8 to 2.1) and are superior to those of 4- to 6-week-old 'Suwannee' bermudagrass (1.3 to 1.8) and 'Pangola' digitgrass (1.3 to 1.7) in similar studies (8 and 14).
MANAGEMENT FOR HA Y
Florigraze can be used in a pure stand or in a mixture with grasses for hay. Established rhizoma peanuts grow very well with improved bahiagrasses, digitgrasses and bermudagrasses. Florigraze cut twice a year for hay makes a satisfactory quality hay. However, cutting three times (particularly in Peninsular Florida) will give improved quality and, in most years, higher yields than just two harvests.
Grasses need to be cut four or more times per year for the best quality hay, so if cut only two or three times as recommended for rhizoma peanut-grass mixtures, the grass portion of the hay is very poor quality. For this reason, and also because Florigraze furnishes the nitrogen, Florigraze should make up 75% or more of a mixture grown for hay. The best quality hay would come from pure (100%) stands of Florigraze. However, in actual practice it is difficult to grow rhizoma peanuts without some contamination by volunteer annual and/or perennial grasses. The last hay harvest of a season may be critical in maintaining the vigor of the Florigraze stand. If a crop of hay is cut, and regrowth takes place for only a short period of time and is killed by frost before food reserves are restored in the rhizomes, the plant will be weakened. This problem has not yet been researched, but if the last cutting can not be made 5 or 6 weeks before killing frost is expected, it may be best to wait until frost occurs and then cut hay. Frost-killed top growth can also be grazed.
Rhizoma peanuts excel for hay production, as they are high in dry matter content. At the hay stage, it commonly exceeds 25% dry matter. This means rapid drying and early baling of hay. However, the hay is high quality, and when rained upon, rots rapidly. Managers may decide to both cut hay and graze during the same season.
The persistence, high quality, and yield of Florigraze peanut makes it a potential crop for dehydrating as a high quality hay or leaf meal. It should compare very favorably to alfalfa hay and leaf meals and should be useful for the same purposes. Leaf meal made from Florigraze has high xanthophyll levels and was as effective as alfalfa leaf meal in maintaining yolk color of eggs (3). The pelleting characteristics of Florigraze hay have not been studied.
Because of the limited number of plantings of Florigraze peanut, grazing observations have been limited. A Florigraze-Pensacola bahiagrass pasture was closely grazed by cattle for six years, and the Florigraze stand maintained and even increased. No N was applied to this pasture. Florigraze-Pensacola bahiagrass pastures have been grazed successfully by horses at the Horse Research Unit near Ocala for two seasons.
Rhizoma peanuts, including Florigraze, are surviving in a plot area which became lawn in 1964 and which has been mown since then every 2 weeks during the summer season. Thus, it appears that close defoliation or heavy grazing will not eliminate established Florigraze from a stand. Under such conditions, the Florigraze goes into a rosette type growth, and leaves are oriented flat on the ground, where they cannot easily be removed by grazing. This is a survival phase and not a rapid growth stage; consequently, rhizoma peanut maintained under such grazing pressure produces low forage yields.
When Florigraze is not overgrazed, it assumes an erect habit of growth and is easily consumed by grazing animals. If Florigraze is to fix nitrogen for grass and make a substantial amount of forage, it must have enough top growth for leaves to adequately intercept incoming light. This means that continuous grazing should be at a stocking rate low enough for peanut growth to maintain an average height of at least 4 inches (10 cm). Rotationally-grazed Florigraze should not be grazed longer than 10 days, and a 3-week or longer rest period should proceed the next grazing period.
If another plant cuts off the sunlight normally received by the peanut, then the peanut plant is weakened in proportion to amount of shading. The taller plant, be it weed or companion forage grass, must be removed by mowing or grazing if the peanut is to be maintained in the most vigorous condition. However, well-established rhizoma peanut plants can survive under shading for long periods of time. Undergrazing of a Florigraze-grass mixture, particularly when nitrogen fertilization has been added to stimulate the grass, may reduce the peanut in established stands. Similarly tall weeds can damage stands.
Mixtures of Florigraze with bahiagrass, digitgrass, and bermudagrass have grown well with no nitrogen fertilizer added. In these mixtures the grass is dependent upon the peanut for most of its nitrogen. The grass gets its nitrogen from the breakdown of peanut plant material and from manure and urine of livestock grazing the mixture. Because the productivity of a peanut-grass sod depends upon the nitrogen-fixing properties of the peanut, the peanut should
be the dominant plant in the sod and should make up two-thirds or more of the stand.
Cattle readily eat Florigraze forage, but usually do not select the peanut to the exclusion of the grass. There is a tendency, where density of peanut stands vary, to graze both grass and peanuts first in the areas where the peanut is the thickest. For this reason, uniform stands of peanut in grass mixtures are desirable.
Pure stands of Florigraze peanut could be planted in small pastures adjacent to larger perennial grass pastures. Suitable openings through the fence would allow calves to supplement their diet by grazing the better quality peanut pasture from late April to early October. Such creep pastures should be near areas where the cattle naturally congregate, such as a watering tank or shade. Creep grazing of the summer annual legumes, hairy indigo (Indigofera hirsuta L.) and joint vetch (Aeschynomene americana L.), has profitably increased both daily gains and total weight of calves where their mothers were grazing Pensacola bahiagrass (9). Florigraze should give similar benefits without the need for annual establishment.
Florigraze grows better in the spring if the top growth of the previous season is grazed, mown closely, or burned off. Leaf disease in spring is usually associated with dense dead topgrowth remaining from the previous season. When the peanut top growth is killed by frost, the dead top growth can be burned off without damage to the peanut, if burned before new shoots emerge after a killing frost. Cool-season weeds often grow in the rhizoma peanut sod during winter and can compete with the peanut during early spring. It will be possible to control these weeds with herbicides when approved. Some control of winter weeds is possible by close mowing of weeds in spring before peanut is high enough to be damaged by the mowing.
FERTILIZATION AND LIMING
ESTABLISHED RHIZOMA PEANUTS
The rhizoma peanut is an excellent competitor for nutrients available in the soil and will give good growth on rather infertile soils. The amount of fertilization depends upon the type of use and
amount of forage produced. If the peanut is used as pasture, where nutrients are recycled, annual applications of 300 to 500 pounds per acre (340 to 560 kg/ha) of 0-10-20 or 0-10-30 (N-P205-K20) fertilizer should maintain the peanut or peanut-grass mixtures. When Florigraze is used as a hay plant, the fertilizer amounts applied should at least replace the amounts of nutrients removed in the hay. Table 8 gives an estimate of the fertilizer nutrients needed to replace nutrients in different quantities of hay. For example, a 6-ton (13.4 t/ha) crop will contain 34 pounds/acre (38 kg/ha) P and 210 pounds/acre (235 kg/ha) of K. The amount of P and K in 6 tons (13.4 t/ha) of hay is equal to about 850 pounds per acre (950 kg/ha) of 0-10-30 (N-P205-K20) fertilizer. Sulfur needs would be roughly equivalent to P. Applications of fertilizer in March and in July are recommended for hay production. Continuous high hay yields will require heavy fertilization, though peanut may often make excellent hay yields for several years on residual soil fertility.
The nitrogen need of Florigraze is supplied by nitrogen-fixing Rhizobium bacteria; hence the recommendation to inoculate. new peanut plantings with Rhizobium peanut inoculant. Florida soils normally contain native Rhizobium bacteria which will infect rhizoma peanuts, but natural inoculation is often inadequate in the planting season for maximum growth. Nitrogen fertilization has reduced both the nodulation and spread of establishing Florigraze and reduced the amount of peanut in a Florigraze mixture (1); nitrogenous fertilizer therefore should not be applied to Florigraze,
Table 8. Amount of nutrients in different yields of Florigraze peanut hay.
Nutrients in Oven-Dry Hay
or Nutrient ------------- tons/acret hay yield ------Compound Contentt 1 2 3 4 5 6
% --------lb/At of nutrient-N 2.24 45 90 134 180 224 269
P .28 6 11 17 22 28 34
P205 .64 14 25 39 50 64 78
K 1.74 35 70 104 139 174 209
K20 2.10 42 84 125 168 209 251
Ca 1.52 30 61 91 122 152 182
Mg .47 9 19 28 38 47 56
t Based on data from Table 6.
To convert tons per acre (tons/A) to metric tons per hectare (t/ha), multiply tons/A
by 2.24; to convert lb/A to kg/ha, multiply lb/A by 1.12.
either alone or in mixtures. The Ca and Mg content of peanut hay is high (Table 5), so dolomitic limestone will need to be applied every few years. It would take about 840 pounds (940 kg/ha) of dolomitic limestone containing 54% CaC02 and 44% MgC02 to replace both Ca and Mg contained in 6 tons (13.4 t/ha) of hay. Adequate quantities of all essential minor elements must be supplied for good peanut growth. If the minor element status of the soil is unknown, application of a complete minor element mixture, such as FTE 503, is recommended.
Insect pests have not been troublesome on Florigraze rhizoma peanut. Two leaf spot diseases caused by Phyllosticta and Stemplylium fungi have been identified by Freeman (5), but no long term or serious damage has been observed from these or other diseases. Also, no buildup of pathogenic nematodes has been observed in rhizoma peanuts. The relative freedom of Florigraze peanuts from pests may be due to the relatively small acreages involved. Greater pest damage is expected when acreage of Florigraze increases and the crop comes into contact with a greater variety of pests.
Rhizoma peanuts can be grown alone or in mixture with grasses as a ground cover in sunny and lightly shaded areas having low traffic. The bright flowers of rhizoma peanuts add interesting contrast to the green foliage. Florigraze does not flower as profusely as Arb and Arblick when used for ground cover. The peanut can be allowed to grow tall or can be cut frequently and maintained as a lawn. When managed as a lawn, rhizoma peanuts probably should not be cut closer than 2 inches (5 cm) above the soil.
Florigraze and similar rhizoma peanuts offer promise of beautifying the road shoulders along highways where good soil drainage is available. The peanut should be useful in reducing erosion, both by forming a dense rhizomatous sod and in furnishing nitrogen for perennial grasses in mixture with the peanut. The relatively short, dense growth of rhizoma peanuts would not require frequent mowing.
Good nitrogen-fixing ability and a low dense cover make Florigraze and other rhizoma peanuts potential cover crops for use in orchards and vineyards not requiring a clean soil surface. Rhizoma peanuts have been planted between rows of pecans, oranges, peaches, and grapes. The benefits of planting peanuts in this manner have not quantified yet. Maximum benefits should occur if peanuts are planted at the same time as the fruit crop. The peanut should compete very little with fruit crop during the establishment year and provide free nitrogen and weed protection in following years. The peanut can be mown as necessary. Peanuts could be cut for hay during the time that fruit or nut crop plants have only a small canopy, as the canopy is developing; the peanut would be restricted to areas not densely shaded.
Because of its long establishment period, rhizoma peanut will usually not be destroyed to plant another crop until after many years growth. However, when an established peanut sod is plowed or destroyed it can furnish up to 425 pounds of N per acre to following crops (3).
Ryegrass and other cool-season annual crops which can germinate with only shallow soil surface scarification can be planted in rhizoma peanut sod. Care should be taken that peanut rhizome system is not damaged in planting. How much damage such a cool-season crop causes to the peanut in the following season has not been determined. Any damage to peanut should be minimized if the winter crop is not allowed to make dense, tall growth in the spring period. Grazing, mowing for hay, or harvesting for silage are possible methods of controlling the winter crop in spring to minimize damage to the peanuts.
Florigraze and other rhizoma peanuts should not become serious weedy pests. The peanut grows on its original planting site unless physically moved to other sites. The rhizoma peanut is easily killed by plowing the soil with moldboard plow and harrowing once or twice at intervals to kill sprouting shoots. Breaking up the rhizome mat greatly weakens the peanuts, and developing shoots are reduced in number and vigor. Consequently rhizoma peanuts are much easier to eradicate than rhizomatous grasses such as bermudagrass.
Distribution of Florigraze rhizome planting material to commercial rhizome growers was made in February 1979 and January and February, 1980 and will continue in January and February, 1981. Florigraze rhizomes should become commercially available in winter of 1981-82 from rhizome growers that received planting material in February 1979 and January and February, 1980. Anyone desiring to obtain foundation stock of Florigraze to produce rhizomes or needing lists of commercial rhizome growers who have received foundation stock should contact:
Florida Foundation Seed Producers Inc.
P. 0. Box 309
Greenwood, FL 32443
Phone (904) 594-4721
1. Adjei, M. B., and G. M. Prine. 1976. Establishment of perennial peanuts (Arachis glabrata Benth.). Soil and Crop Sci. Soc. Fla. Proc.
2. Blickensderfer, C. B., H. J. Haynsworth, and R. D. Roush. 1964. Wild
peanut is promising forage legume for Florida. Crops and Soils
3. Breman, J. W. 1980. Forage growth and quality of Florigraze perennial peanut (Arachis glabrata Benth.) under six clipping regimes.
Masters Thesis, Univ. of Fla. Agronomy Dept. 59 p.
4. Damron, B. L. 1979. Unpublished data. Univ. of Fla. Poultry Sci. Dept.
5. Freeman, T. E. 1975. Personal communication. Univ. of Fla. Plant
6. Gregory, W. C., M. P. Gregory, A. Krapovickas, B. W. Smith, and J. A.
Yarbrough. 1973. Structures and Genetic Resources of Peanuts. In Peanut Culture and Uses. American Peanut Res. and Ed. Assoc. Inc.,
Stillwater, Oklahoma. Pp. 47-133.
7. Hermann, F. J. 1954. A synopsis of the genusArachis. USDA Agricultural Monograph No. 19. 26 p.
8. Moore, J. E., and 0. C. Ruelke. 1978. Composition and quality of'Florida 66' alfalfa, 'Suwannee' bermudagrass and 'Pangola' digitgrass
hays. The Fla. Beef Cattle Res. Rept. 1978. Pp. 61-64.
9. Ocumpaugh, W. R. 1979. Creep grazing for calves. Proc. 28th Annual
Beef Cattle Shortcourse. Univ. of Fla., Animal Sci. Dept. Pp. 159-165.
10. Prine, G. M. 1964. Forage possibilities in the genus Arachis. Soil and
Crop Sci. Soc. Fla. Proc. 24:187-196.
11. Prine, G. M. 1973. Perennial peanuts for forage. Soil and Crop Sci. Soc.
Fla. Proc. 32:33-35.
12. Williams, M. 1973. Perennial peanuts look good for forage. Sunshine
State Agric. Res. Rep. 18(4-5): 14-16.
13. Powell, John. 1967. Personal communication. SCS Plant Materials
Center, Americus, Ga.
14. Tiharuhondi, E. R. 1974. Influence of management on herbage yield,
persistence, carbohydrate reserves and nutritive value of 'African' and 'Florida 66' alfalfa (M'dicago .stira L.). Ph.D. Dissertation, Univ. of
Fla. Agronomy Dept. 183 p.
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