INTRODUCTION

'Floralta' Limpograss (Hemarthria altissima [Poir] Stapf and C. E. Hubb) is the direct release of an increase of USDA plant introduction 364888. This introduction was first extensively evaluated in Florida beginning in 1974. A systematic evaluation of performance in small plot experiments and grazing animal experiments has shown Floralta to be superior to the other released limpograsses in total dry matter yield. Floralta is superior to 'Redalta' and 'Greenalta' limpograss in in vitro organic matter digestion (IVOMD) and generally equal to or perhaps slightly lower in IVOMD than 'Bigalta'. Floralta was specifically selected for persistence under grazing and is markedly superior to Bigalta. Floralta is best adapted to the poorly drained sandy soils of peninsular Florida, but good production has been obtained in west Florida also. Superior production data on Floralta have been reported from Venezuela, Ecuador, and New Zealand.

ORIGIN AND DESCRIPTION

Floralta limpograss is a stoloniferous perennial tropical grass of the tribe Andropogonea of the family Poaceae. The plant introduction (P.I.364888) now designated as Floralta was originally collected from a small island in the Luvuvhu River several kilometers above its confluence with the Limpopo River in Kruger National Park, Republic of South Africa (Oakes 1973). Floralta has a tetraploid chromosome number (2n = 36) (Quesenberry, et al., 1982). Like most other limpograsses, Floralta produces few seed, and is thus vegetatively propagated. Its general morphological appearance is similar to Bigalta in that it has larger stems and wider leaves than the diploid Redalta and Greenalta cultivars. Floralta has a more intense purple coloration under cool temperature stress or fertility deficiency than Bigalta, but it generally does not show the intense red pigmentation that Redalta shows under similar environmental conditions. Floralta appears to be similar to other released cultivars of limpograss in winter hardiness. Oakes (1980) reported that Floralta showed 80% survival, whereas Redalta, Greenalta, and Bigalta had 84%,78% and 76%, survival, respectively, at several locations in the United States. At a more temperate latitude (49°S) in New Zealand, Floralta was significantly more winter hardy than Bigalta.

SMALL PLOT EVALUATIONS

Gainesville, Florida

A series of forage yield and performance experiments at Gainesville, following the scheme proposed by Quesenberry et al. (1977) led to the initial identification of Floralta as a superior genotype. The first of these experiments was a small plot clipping trial established at the Beef Research Unit (BRU) near Gainesville in 1974 (Ruelke et al., 1976). Floralta was the top yielding genotype in this experiment in both 1975 and 1976 with markedly superior performance in 1976. The IVOMD data from 1976 shows that Floralta was superior to Redalta and Greenalta and comparable to Bigalta (Table l ).

In late 1976, a second series of small plot experiments was established to compare a selected group of limpograss genotypes under clipping defoliation and under mob grazing defoliation. Mob grazing is a research technique for forage evaluation where a large number of cattle are allowed to consume in 1 to 3 days the forage production from small plots of a number of different forage genotypes. The animals are then removed and the grass is allowed to regrow. Both experiments were planted at the BRU and first harvested in 1977. The clipping experiment was harvested four times at 5-week intervals. The clipping plots were fertilized with 200 Ibs/A 16-4-8 (N-P2O5-K2O) complete fertilizer with micronutrients after each harvest. The mob grazing experiment was grazed five times at 5-week intervals. The grazing plots received 300 Ibs/A of 0- 10-20 fertilizer in the spring of each year and 100 Ibs/A of 33-0-0 fertilizer before each regrowth period. The yield of the grazed plots was estimated using a simple disk meter and converted to Ibs/A by multiplying total disk heights by the regression coefficient of 110. Table 2 shows that Floralta limpograss was superior to other cultivars in both 1977 and 1978 in total yield and persistence under clipping defoliation. The IVOMD data from 1977 show that Floralta is comparable to Bigalta under similar management conditions and superior to Redalta and Greenalta. Floralta had persistence superior to Bigalta under grazing defoliation in both 1977 and 1978. The higher yields of Redalta and Greenalta in 1978 under grazing are probably due to poorer animal acceptance of these cultivars than of Floralta. The technique used in mob grazing resulted in more complete utilization of Floralta than Greenalta and Redalta. Thus at the end of the grazing period Floralta had less stubble than Greenalta and Redalta, which resulted in less regrowth for Floralta than for Greenalta and Redalta. In 1979 Floralta was highest in yield and maintained good persistence.

Following these clipping and grazing experiments, an experiment was initiated in 1980 (Christiansen 1982) to study the effects of several different defoliation and N fertilization treatments on Floralta, Bigalta, and Redalta. Table 3 is an abstract of a portion of these data and shows that Floralta was generally either first or second in total dry matter yield at all defoliation frequencies and all N fertilization levels. At the 9-week defoliation treatment Floralta yielded 10,890 lbs/A when fertilized with approximately 110 lbs/A of N. This treatment approximates the type of yields that could be expected under a stockpiling management regime. Of interest also are the extremely high yields obtained on Floralta with approximately 430 lbs/A of N, harvested at either the 9 or 18-week defoliation frequency.

An experiment designed to evaluate the fall production potential of Floralta was initiated on August 1, 1981 (Ruelke and Quesenberry 1983). Previous summer growth of Floralta was removed to a height of approximately 3 inches on August 4, 1981, and 67 Ibs/A of N was applied as 15-5- 10 fertilizer. Dry matter yield harvests were then taken at 2-week intervals beginning 4 weeks after the initial staging of the experiment and continuing until February 1, 1982. As shown in Figure 1, Floralta reached a yield plateau of approximately 9,000 lbs/ A about October 1, with only minimal accumulation of dry matter occurring after this date. A slight decrease in total dry matter accumulation occurred after the first killing frost. Little or no additional accumulation occurred in north central Florida prior to the termination of the experiment on February 1. Crude protein (CP) content declined as the grass matured to levels at which animals may require supplementation after about October 1. These low CP values were similar to those found with the other limpograsses in previous research (Quesenberry and Ocumpaugh, 1980).

ARC, Jay, Florida

Floralta and Redalta limpograsses have been compared with a number of bermudagrasses in northwest Florida at the Jay Agricultural Research Center (ARC). Table 4 shows that Floralta gave comparable yields to the best yielding bermudagrasses in the establishment year (1978); however, in 1979 and 1980, yields of the limpograsses were generally poorer than the bermudagrasses. These data probably indicate that this cooler and dryer location in northwest Florida is not as well suited for limpograss production as the warmer and wet, sandy, flatwood soils of central and south Florida.

Floralta limpograss has also been compared at the Jay ARC with two other pasture grasses ['Tifton 44' bermudagrass (Cynodon daclylon L.) and 'Pensacola' bahiagrass (Paspalum notatom Flugge)], planted in combination with 'Florigraze' rhizome peanut. This peanut-grass experiment, established in 1980, was harvested in 1981 on August 24, and on June 16 and August 30 in 1982. Floralta maintained a better grass-peanut mixture and was highest in total dry matter yield in 1981 and 1982 (Table 5). In the spring of 1982 all legume-grass combinations showed a high percentage of Florigraze rhizome peanut. Summer 1982 production shows a higher percent of Floralta and significantly greater total dry matter yield than the other grass-legume combinations.

New Zealand

Floralta has received only limited evaluation at international locations. In one experiment at Palmerston North, New Zealand (a rather temperate environment at latitude 40° south), Floralta was compared with four other limpograsses including Bigalta. Floralta yielded 11,690 lbs/A vs 10,800 for Bigalta in the first year of this experiment; however, the best yielding introduction yielded 15,800 lbs/A. These yield differences are probably due to variability in winter hardiness. Floralta was more winter hardy than Bigalta at this location, but less winter hardy than two other unreleased plant introductions (PI. 364884 and 349753). These results suggest that Floralta is probably not suited to colder locations in the southeastern United States.

INTERMEDIATE LEVEL GRAZING EVALUATIONS

Gainesville, Florida

A mob grazing experiment was initiated in 1977 on Floralta and seven other advanced lines of limpograss to evaluate production and persistence under grazing conditions. Each of four approximately 1/4 acre pastures was assigned one of the four different grazing defoliation frequencies (3, 5, 7 and 9 weeks). Small plots of the eight different limpograsses were vegetatively established in the summer of 1977 in two replications in each pasture. Grazing treatments were imposed in the spring of 1978. By the end of the first season Bigalta and PI. 364874 were showing marked decreases in percent stand of limpograsses at the 5,7, and 9-week grazing frequencies compared with Floralta. The marked superiority of Floralta in overall persistence was clearly demonstrated by the end of the third season (Figure 2). At the 3, 5, and 9-week defoliation intervals, both Bigalta and P.I. 364874 had drastic stand reduction, whereas Floralta and Redalta remained near 80% ground cover at all four defoliation frequencies. A major factor contributing to the persistence of Redalta is poor animal acceptability. Floralta, however, showed no evidence of animal unpalatability and plots were generally grazed as closely as Bigalta.

ARC, Ona, Florida

A companion mob grazing experiment similar in design to the one at Gainesville was established at the ARC, Ona in 1978, and grazing treatments were imposed in 1979. Grazing defoliation frequencies in this experiment were 3, 6, 9, and 12 weeks. Common bermudagrass (Cynodon daclylon L.) is a major weed problem at this location in improved pasture experiments and often becomes the predominant species under heavy grazing pressures. Floralta had consistently higher percent ground cover than Bigalta at all grazing frequencies in both years of this experiment (Figure 3). These data suggest, however, that frequent, close defoliation of Floralta may also result in increased weed competition. Dry matter yields taken prior to each grazing from April 1980 to March 1981 show that Floralta yielded more than Bigalta at all grazing frequencies (Table 6).

ANIMAL PERFORMANCE

Gainesville, Florida

In 1980 an animal performance grazing trial designed to compare beef gains on Floralta limpograss and Pensacola bahiagrass (Paspalum notatum Flugge) was established at the BRU. Grazing was initiated on these pastures in the spring of 1981, using the put-and-take technique to maintain an adequate level of available forage. The Floralta paddocks were ready to graze approximately 6 weeks earlier than the Pensacola bahiagrass paddocks, and continued producing forage 28 days longer in the fall than Pensacola (Figure 4). Mean number of animals per/acre was 1.2 throughout the grazing season for Pensacola and varied from 1.2 to 2.4 on Floralta with a mean of 1.63 throughout the grazing season. Average daily gains (ADO) were similar on Floralta and on Pensacola bahiagrass (0.77 and 0.72 lbs/A, respectively); however, the increased carrying capacity and additional calendar days of grazing per acre resulted in an almost two-fold difference in total gain per acre for Floralta. The 1982 results of this grazing experiment again showed that animal days per acre and average number of animals per acre were greater for Floralta limpograss than Pensacola bahiagrass, although ADG was slightly higher for Pensacola than Floralta (Table 7). In 1982 the Floralta pastures appeared to be under utilized in the early part of the grazing season resulting in lower quality forage and thus lower ADG in the late summer and fall. Floralta pastures should be grazed sufficiently close in the early summer to prevent a buildup of mature stems near the soil.

Ecuador

Mixed grass-legume pastures of Floralta limpograss, Neonotonia wightii (Arnott) Lackey, and Centrosema pubescens Benth, were compared with other pastures of guinea grass, Panicum maximum Jacq, and Neonotonia wightii in a grazing experiment conducted at the Pichilingue Tropical Experiment Station in Ecuador. Data from the 1981 grazing season show that average daily gains on Floralta limpograss plus legume pastures were slightly higher during the wet season and considerably higher during the dry season (Table 8). However, the robust guinea grass carried a greater number of animals per acre compared to Floralta limpograss (0.96 vs. 0.80, respectively) and, thus, total gains per acre on the guinea grass-legume mixture were higher in the wet season but equal to the Floralta limpograss-legume mixture in the dry season. These data suggest that Floralta limpograss is well adapted to a tropical environment with alternating wet and dry seasons and shows promise for animal gains similar to the more robust guinea grass under similar management conditions.

PEST PROBLEMS

No major insect problems have been observed on Floralta limpograss. The armyworm complex which attacks many tropical grasses in Florida can cause severe damage in isolated circumstances. Damage appears to be no worse on Floralta than most other tropical grasses. In a series of sting nematode (Belonolaimus longicaudatus Rau) tolerance trials (Quesenberry and Dunn, 1978), Floralta was significantly poorer in sting nematode tolerance than the most tolerant line; however, it was not significantly different from the released cultivars of Bigalta and Redalta in sting nematode tolerance. Floralta was significantly less susceptible to the yellow sugar-cane aphid (Siphaflava Forbes) than Pangola digitgrass (Digitaria decumbens Stent), and was not different from Greenalta (Oakes, 1978).

No major foliar diseases of Floralta limpograss have been identified.

WINTER HARDINESS

Oakes (1980) has shown that Floralta limpograss was slightly less winter hardy than Redalta, but equal to or more winter hardy than Greenalta and Bigalta. Research experience in Florida has indicated that little or no winter killing occurred in Gainesville with minimum temperatures of 14°F ( - 10°C). Observations at the ARC, Jay, Florida, indicate that some winter killing did occur during the winter of 1981-82. The minimum temperature experienced at this location was 8°F ( - 13°C) with the temperature below freezing for 53 consecutive hours. Plot studies at the ARC, Ona, indicated that Floralta was more cold tolerant than Bigalta in 1981 -82. The minimum low temperature at this location was 14°F. Other data from New Zealand also indicate that Floralta is superior to Bigalta in winter hardiness.

PRODUCTION AND MANAGEMENT

RECOMMENDATIONS

Initial Establishment

Floralta limpograss is vegetatively propagated. It produces few, if any, viable seed. Ruelke et al. (1978) compared three planting techniques (sprigged, sprigged and disked, and sprigged and disked, plus cultipacked) for establishment of limpograss. The disked, and disked, plus cultipacked establishment methods, where two-thirds or more of the limpograss stems were covered with soil, were superior planting techniques to simple spreading of the material on top of the soil without disking. A soil compaction operation such as cultipacking or rolling is recommended to improve establishment of limpograss. In this experiment, planted on August 1, 1977, Floralta spread more rapidly than Redalta, but slightly less rapidly than Bigalta. Ratings from the experiment taken on April 17, 1978, (8 months after planting) showed that Floralta had overall higher percent ground cover than both Redalta and Bigalta, resulting in greater 1978 total dry matter yield from comparable establishment treatments. This experiment demonstrates that within 3 months after establishment a satisfactory percent ground cover can be obtained from Floralta. Establishment year fertilization in this experiment at Gainesville was 66, 20, and 40 lb/A of N, P2O5, and K2O, respectively.

Mature Floralta planting material should be mowed, allowed to wilt only slightly, and baled green for transportation to a new planting area (Figure 5). Experience has shown that a bermudagrass sprig planter can be used effectively for establishing Floralta limpograss; however, for rapid coverage it is recommended that the normal 40 inch planting row spacing of this device should be reduced to 20 inch centers. Using a bermudagrass sprig planter with 20 inch rows requires approximately 15 to 20 bales per acre for establishment. An alternate approach is broadcasting planting material, either by hand or mechanically, and incorporating it into the soil. Observations have suggested that a supplemental nitrogen application 2 to 3 weeks prior to mowing planting material promotes more rapid establishment. Establishment fertilizer should be low in nitrogen and high in phosphorus and potassium to encourage root development without promoting excess weed growth. A minimum rate of 400 Ibs/A of 5-10-15 with minor elements should be applied prior to planting. When Floralta plants reach about 4 to 5 inches in height, an application of Dicamba (3, 6-dichloro-0-anisic acid) at 0.5 to 0.75 lbs/A may be useful to control broadleaf weeds. Once the grass becomes well rooted, nitrogen should be applied to stimulate forage growth.

Annual Maintenance

Research at Gainesville has shown that Floralta responds with increasing dry matter yields to nitrogen fertilizer application up to 430 lbs/A of N (Table 3); however, these rates are not generally recommended. In this same experiment, yields of 10,890 lbs/A were obtained with 110 lbs/A of N at 9-week harvest intervals. N fertilizer at this level also produced adequate crude protein content. N, P2O5, and K2O aplied in a 4:1:2 ratio generally is acceptable for tropical grasses. Follow soil test recommendations to avoid any nutrient deficiencies.

Limpograss is moderately susceptible to 2, 4-D herbicide, and this product is not recommended for use on Floralta for broadleaf weed control. Dicamba, used at the recommended rates, has shown no phytotoxicity on limpograss and can be used for maintenance control of broadleaf weeds in Floralta. Read and follow label directions concerning grazing of herbicide treated pastures. Weed invasion should be less in Floralta pastures than in Bigalta pastures because of Floralta's superior persistence.

PLANTING MATERIAL

Vegetative planting material will be available in the summer of 1984 at the Beef Research Unit, Gainesville, Florida, and at the ARC, Ona, Florida. Distribution will be on a limited quantity basis.

The Florida Foundation Seed Producers, Inc., PO. Box 309, Greenwood, Florida, 32433, will maintain a list of growers who have obtained foundation planting material for future distribution to producers.

LITERATURE CITED

1. Christiansen, Scott. 1982. Energy reserves and agronomic characteristics of four limpograsses (Hemarthria altissima (Poir) Stapf et C.E. Hubb) for Florida's flatwoods. Ph.D. Dissertation. University of Florida.
   
   
2. Oakes, A.J. 1973. Hemarthria collection from South Africa. Turrialba 23:37-40.
   
   
3. Oakes, A.J. 1978. Resistance in Hemarthria species to the yellow sugar
   cane aphid, Sipha flava (Forbes). Trop. Agric. (Trinidad) 55:377-381.
   
   
4. Oakes, A.J. 1980. Winter-hardiness in limpograss, Hemarthria altissima. Proc. Soil Crop Sci. Soc. Fla. 39:86-88.
   
   
5. Quesenberry, K.H., and R.A. Dunn. 1978. Differential responses of He

   marthria genotypes to sting nematodes in a greenhouse screening trial. Proc. Soil Crop Sci. Soc. Fla. 37:58-61.
   
   

6. Quesenberry, K.H., A.J. Oakes, and D.S. Jessop. 1982. Cytological and geographical characterizations of Hemarthria. Euphytica 31 :409-416.
   
   
7. Quesenberry, K.H., and W.R. Ocumpaugh. 1979. Persistence, yield, and digestibility of limpograss genotypes under clipping and grazing. Agronomy Abstracts. p. 108.
   
   
8. Quesenberry, K.H., and WR. Ocumpaugh.1980. Crude protein, IVOMD, and yield of stockpiled limpograss. Agron. J. 72: 1021-1024.
   
   
9. Quesenberry, K.H., Rex L. Smith, S.C. Schank, and W.R. Ocumpaugh. 1977. Tropical grass breeding and early generation testing with grazing animals. Proc. 34th Southern Pasture and Forage Crop Improvement Conference.
   
   
10. Ruelke, O.C., and K. H. Quesenberry. 1983. Effects of fertilization timing on the yields, seasonal distribution, and quality of limpograss forage. Proc. Soil Crop Sci. Soc. Fla. 42: 132-36.
    
    
11. Ruelke, O.C., K.H. Quesenberry, and W.R. Ocumpaugh. 1978. Planting technique effects on establishment, ground cover, production and digestion of Hemarthria altissima (Poir) Stapf et C.E. Hubb. Proc. Soil Crop Sci. Soc. Fla. 38:40-42.
    
    
12. Ruelke, O.C., K.H. Quesenberry, and D.A. Sleper. 1976. Comparison of greenhouse vs. field plot techniques for evaluating new germplasm of limpograss (Hemarthria altissima (Poir) Stapf et C.E. Hubb). Agronomy Abstracts. p. 112.

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