MORFOGÊNESE DO CAPIM-MARANDU SOB TRÊS CONDIÇÕES DE REBAIXAMENTO PARA O DIFERIMENTO

Abstract

The experiment was conducted to verify witch strategy of pasture lowering to stockpiling - in advance of a few months or abruptly and immediately before deferment period - would result in tillers with higher growth rates during the deferment period of Urochloa brizantha cv. Marandu (marandu palisadegrass). The deferment period was 90 days and occurred from 03/15/2017 to 06/15/2017. Three strategies for lowering the plants before the deferment period were evaluated: I) marandu palisadegrass with 15 cm for four months before the start of the deferment period (15/15 cm); II) marandu palisadegrass with 30 cm from November 2016, but at the beginning of the deferment period the plants were lowered to 15 cm (30/15 cm); and III) 45 cm marandu palisadegrass from November 2016 until the start of the deferment period, when the plants were lowered to 15 cm (45/15 cm). The experiment was conducted in a completely randomized design with four replicates. The evaluation of morphogenesis occurred in two periods. The phyllochron of the canopy under 15/15 cm was larger than those under 30/15 cm and 45/15 cm. Leaf life span was higher in grass managed with 15/15 cm than in grass with 30/15 cm. The leaf elongation rate (LER) at the beginning of the deferment was higher in the grasses managed with 30/15 cm and 45/15 cm, compared to that under 15/15 cm. However, the LER did not vary between the retraction strategies at the end of the deferment period. The lowering of marandu palisadegrass from 30 or 45 cm to 15 cm at the beginning of the deferment period results in a tillers with a higher growth rate during the deferment period when compared to the maintenance of marandu palisadegrass with 15 cm for four months before deferment period.