| Information on the performance of Ubon Stylo (Stylosanthes guianensis; var. vulgaris x var. pauciflora ), (95 percent of germination) during the establishment period is limited in Puerto Rico. The effect of four seeding rates (5, 10, 15, 20 kg ha-1) of Ubon Stylo on seedling emergence per m 2, vigor (height every three weeks), dry matter yield (DM; kg ha -1) and botanical composition (percent of Ubon Stylo and weeds) when harvested at 98 day after sowing (DAS) was evaluated. Seeding rates was achieved with a calibrated Brillion seeder. There were significant differences (p<0.05) between seeding rates on seedling emergence. There was an increase in seedling emergence 18 to 89 plants per m2 as seeding rates increased from 5 to 20 kg ha-1. There was no interaction between seeding rate x time of measurement (p>0.05) on plant height. A quadratic and logarithmic increase in plant height was observed with increasing seeding rates. Plant heights were greater than 80-cm for the 10 to 20 kg ha -1 seeding rates. Seeding rates also had an effect on DM yield and botanical composition. An increase of 47 percent (2,900 kg ha-1 ) was observed when the seeding rate increased from 5 to 10 kg ha -1. The proportion of Ubon Stylo in the samples from the 10, 15, and 20 kg ha-1 seeding rates were 84, 84 and 87 percent, respectively. The lowest proportion (61 percent) of Ubon Stylo was observed at the lowest seeding rate (5 kg ha-1). In conclusion, a seeding rate of 10 kg ha-1 of Ubon Stylo provides suitable plant populations (42 plants per m2), adequate plant heights ≥ 80-cm, and 84 percent composition of Ubon Stylo which surpassed the 6,000 kg of DM yield at 98 DAS.;After the establishment phase, DM yield and crude protein (CP) effects were evaluated for four seeding rates, three cutting heights (10, 15, and 20-cm), and four harvests. Four seeding rates were the main plots, and cutting heights were the sub-plots. Ubon Stylo at 90 day regrowth was harvested four times during the year (harvest times were the sub-sub-plots). The analysis shows that the differences in the DM yield, obtained by influence of the mean effect of cutting height were not significant, moreover, these differences in DM yield were not significant to the interactive effects of seeding rate x cutting height x time of harvest, nor a seeding rate x cutting height, or cutting height x time of harvest interaction (p>0.05). There was, however, a significant interaction (p<0.05) between seeding rate x harvests time. A higher DM yield for the June harvest (13,000 kg ha-1) at the 15 kg ha-1 seeding rate was observed. There were seeding rate main effects (p=0.0630) and time of harvest effects (p<0.05) on DM. The highest DM yields were observed for the 10 and 15 kg ha -1 seeding rates. Yields of DM in June were greater than those of March and December, 47 percent and 32 percent, respectively. There were no significant treatment effects on crude protein, averaging 13 percent. In conclusion, Ubon Stylo cutting height can range from 10 to 20-cm. This study also found that the 10 kg ha-1 seeding rate resulted in the highest DM yield. In addition, the high DM yields observed during the summer months suggest that the harvest periods can be shortened during the summer season to improve crude protein concentration. |
