This worked aimed to evaluate the effects of deferring and grazing periods on the tiller population density, morphological component mass of forage and falling index on Brachiaria decumbens cv. Basilisk pastures. Two assays were carried out: first year and second year. Subdivided plots were used according to a randomized block design with two replicates. The treatments were composed of combinations of deferred periods and grazing periods. In the first year, 103, 121, 146 and 163-day deferring periods were used; and 73, 103, 131 and 163-day deferring periods in the second year. The grazing periods were 1, 29, 57 and 85 days. The increase in the deferring period increased the population density of reproductive tillers (from 37 to 304 tillers/m² in the second year) and reduced the density of vegetative tillers (from 1,253 to 889 tillers/m² in the first year; from 1,235 to 627 tillers/m² in the second year). Throughout the grazing period, decrease in the vegetative (from 988 to 868 tillers/m² in the first year) and reproductive tillers (from 216 to 0 tillers/m² in the first year; from 203 to 0 tillers/m² in the second year) occurred, as well as increase in dead tillers (from 463 to 1,088 tillers/m² in the first year and from 341 to 1,010 tillers/m² in the second year). Pastures subjected to longer deferring and grazing periods showed higher dead stem mass (6093 and 3819 kg/ha of dry mass in the first and second years, respectively) and lower green foliar blade mass (341 and 177 kg/ha of dry mass in the first and second years, respectively). Brachiaria decumbens cv. Basilisk pastures submitted to long deferring and grazing periods have unfavorable structural characteristics to animal production.
deferring period; grazing period; morphological composition; number of tillers; pasture structure
