Perfilhamento do capim-marandu com altura fixa ou variável durante as estações do ano

Abstract

The productivity and stability of a pasture is completely related to tillering of the plant population in the pasture. This study aimed to understand the tillering of Urochloa brizantha syn. Brachiaria brizantha cv. Marandu (marandu palisadegrass) with fixed or variable heights during the seasons of the year and, from that, identify defoliation strategies that optimize their tillering on the pasture. Four defoliation strategies were studied: 15 cm marandu palisadegrass in autumn and winter and 30 cm in spring and summer; marandu palisadegrass 30 cm in autumn, 15 cm in winter and 30 cm in spring and summer; 30 cm marandu palisadegrass in autumn, 15 cm in winter and early spring and 30 cm in late spring and summer; and 30 cm marandu palisadegrass throughout the experimental period. The experimental design was completely randomized with split plots. During the seasons, we evaluated the tiller appearance rate (TAR), tiller mortality rate (TMR), balance (BAL) between TAR and TMR and the stability index (SI). In winter and late spring, TAR and BAL were lower compared to other times of the year. In the pastures managed with 30 cm throughout the experimental period and 30 cm in autumn, 15 cm in winter, 15 cm in early spring, 30 cm in late spring and 30 cm in summer, TMR were higher in winter and early of spring. Marandu palisadegrass has high flexibility for defoliation management, but, leave marandu palisadegrass grow from 15 cm in winter to 30 cm in spring increases tillering. Marandu palisadegrass can be managed 30 cm in autumn, 15 cm in winter and 30 cm in spring and summer.