Leaves per tiller as the criterion to determine optimum defoliation frequency in pastures of Brachiaria decumbens

Revista Facultad Nacional de Agronomía Medellín

Diana Leidy Manrique Luna¹  Juan Evangelista Carulla Fornaguera¹ 

[1] Universidad Nacional de Colombia;

关键词: brachiaria grass;    grazing management;    tropical grasses;    urochloa decumbens;   

DOI  :  10.15446/rfnam.v73n2.77292

来源: DOAJ

【 摘 要 】

Two studies were performed to establish the best defoliation frequency in Brachiaria decumbens using the number of leaves per tiller as a criterion. In the first study, 3,500 tillers with 2, 3, 4, 5, or 6 leaves were collected in 10 farms. The number of green, senescent, and dead leaves was counted. A pooled sample of tillers by each farm with a given number of leaves was analyzed for nutritional quality; a complete randomized block design was used for this study. In a second study, it was implemented a complete ramdomized design with repeated measures over time (2 defoliations), and the effect of defoliating B. decumbens at 3, 4, or 5 leaves per tiller on its growth, dry matter yield, and nutritional quality were evaluated. In the first study, all leaves remained green until the tiller had 3 leaves. At the fourth leaf, few tillers (2.3%) had senescent leaves, but at 6 leaves, most tillers had senescent (40.6%) or dead (24.4%) leaves. Crude protein and digestibility decreased as the number of leaves in a tiller increased (P<0.001). In the second study, the rate of dry matter accumulation was the highest for plots defoliated at 4 leaves (P<0.05). Green stems (43.9%) represented a larger proportion of dry matter than green leaves (31.4%), and their proportions were similar among treatments. Crude protein and digestibility of stems decreased as the number of leaves per tiller increased (P<0.001), but the quality of leaves was similar. These findings suggest that these pastures should be defoliated at 4 leaves per tiller.

【 授权许可】

Unknown