The objective of this study was to evaluate morphogenesis in basal and aerial tillers of marandu grass ( Urochloa brizantha Hochst . ex A. Rich. Stapf “Marandu”) subjected to lowering strategies prior to pasture deferral. The pastures were maintained at 3 mean heights for 5 months (15, 25, and 35 cm), and thereafter those managed at 25 and 35 cm were lowered to 15 cm at the beginning of the deferral period (DP). Pastures maintained at 15 and 25 cm before deferral showed a greater number of basal tillers (1328 and 1281 tillers/m 2 , respectively), but a lower number of aerial tillers (145 and 246 tillers/m 2 , respectively), compared with the pasture managed at 35 cm (959 basal tillers/m 2 and 367 aerial tillers/m 2 ). The lowering strategy did not influence the morphogenesis of aerial tillers during the DP. Basal tillers exhibited a higher elongation rate (0.23 cm/day) and greater stem length (26.04 cm) in the pasture maintained at 15 cm for 5 months before the DP compared with the other treatments. Tiller population decreased from the beginning (1381 basal tillers/m 2 and 477 aerial tillers/m 2 ) to the end (989 basal tillers/m 2 and 127 aerial tillers/m 2 ) of the DP. Morphogenetic characteristics, except for leaf lifespan, were also lower at the end than at the beginning of the DP for both basal and aerial tillers. Stem and leaf lengths of basal and aerial tillers were greater at the end of the DP. Maintaining marandu grass pastures at 15 cm for 5 months before the DP results in a greater number of tillers with increased stem growth during the DP.
Silva et al. (Thu,) studied this question.