A field experiment conducted in 1981 and 1982 at the Corozal Substation to determine the effects of solid cattle manure on the green forage, dry forage, and crude protein yields of stargrass (Cynodon nlemfuensis var. nlemfuensis) and on soil composition, showed that after 720 days the maximum manure application, without supplemental nitrogen fertilization, increased dry forage and crude protein yields significantly over the unfertilized control. Solid manure 65% dry matter and 1.6% nitrogen, .10% phosphorus, and .34% potassium; was applied at six rates (2,800, 5,600, 11,200, 16,800, 22,400 and 31,360 kg/ha/year) Stargrass harvested every 45 days. Manure treatments were supplemented with commercial fertilizer to provide 504, 73, and 336 kg/ha/year of N, P and K, respectively. Two check treatments were included: one received 3,360 kg/ha/year of 15-5-10 fertilizer as a standard fertilization and the other received neither fertilizer nor manure. Surface-applied manure at rates of 2,800, 5,600, 11,200, 16,800 and 22,400 kg/ha/year, supplemented with N, P and K, and the fertilized control gave similar dry forage yields. Stargrass P content tended to increase with manure applications, but K, Ca and Mg contents were similar to the standard fertilization. Soil available P and exchangeable K tended to increase with manure applications.

The persistence and dry forage production of nine accessions (8 Hemarthrias and one Cynodon) in mob grazing were measured during a 387-day period. During the short day season, accession H. altissima USDAPI 364888 produced the highest dry forage yield, but did not differ significantly (P<.05) from the others except for H. altissima USDAPI 364873 and 364875. During the long-day season, H. altissima USDAPI 364888 again produced the highest dry forage yield, not differing significantly (P<.05) from H. altissima 364873, 364875 and 409744 and C. plectostachyum 341818. For the whole 387-day period, accessions H. altissima USDAPI 364888, 364873 and 409744 and C. plectostachyum 341818 showed excellent yields in terms of consumed forage. However, no significant differences (P<.05) were observed among accessions during the period mentioned. Similarly although no significant differences (P<.05) were observed in terms of weed infestation percentages, accessions H. altissima USDAPI 364875 and C. plectostachyum USDAPI 341818 had higher weed infestation percentage than the other accessions. In terms of leaves to stem ratios C. plectostachyum USDAPI 341818 produced the highest percentages without differing significantly (P<.05) from H. altissima USDAPI 364873 and 379617.

The productive potential of 11 guinea grass forage genotypes was evaluated at harvest intervals of 45 days during the short and long day seasons. Guinea grass genotypes PRPI 3637 and 3622 produced the highest dry matter yields. P. maximun PRPI 12917 (cultivar Makueny) was not different from 3637 or 3622 during short days; however, during long days it differed from cultivar 3637. In vitro true digestibility (IVTD) estimated by the predicting equation of Arroyo-Aguilú and Coward-Lord was similar for most cultivars under evaluation. Cultivar Guadalupe produced the highest IVTD values during both seasons. Among all genotypes, P. maximun 3637 and 3634 consistently had the highest average regrowth percentages and the best capacity to recover.

The effects of three seeding rates (3.36, 6.72, and 10.08 kg of clean seeds per ha) and two planting methods (row and broadcast), with and without seedbed firming, on the establishment and yield (green forage, dry forage, and crude protein), of common Guinea grass (Panicum maximum Jacq.) were evaluated for 370 days in an Ultisol. Seeding rates influenced significantly the dry forage and crude protein yields of Guinea grass during the first 3 months of growth. The high rate (10.08 kg/ha) significantly increased dry forage yields by 22 and 49% over the medium (6.72 kg/ha) and low (3.36 kg/ha) seeding rates, respectively. The medium rate significantly increased dry forage and crude protein yields by 23 and 26% over the low seeding rate. Row planting was significantly better than broadcast planting only during the first 3 months of growth, increasing dry forage yields by 23% and crude protein yields by 17%. Seedbed firming after planting did not affect yields either during the first 3 months of growth or over the entire period of study (9 cuttings). During 370 days (9 cuttings) the high and medium seeding rates did not differ significantly with respect to yields; however, both outyielded significantly the low seeding rate. The highest yields were obtained with treatments that combined high seeding rate with row planting. The number of tufts varied among treatments from 4 to 6 per m2. Mean crude protein, P, K, Ca, and Mg contents in the harvested forage were 11.21, .28, 3.13, .75 and .19%, respectively. It was concluded that, a good stand of Guinea grass can be obtained in 3 months when sown in August with 6.72 kgjha of processed seeds or 33.6 kg/ha of unprocessed seeds.