<b> Initial height of pasture deferred and utilized in winter and tillering dynamics of signal grass during the following spring </b>

Abstract

ABSTRACT. Tillering dynamics during regrowth in the spring (September to December 2009) on signal grass (Brachiaria decumbens cv. Basilisk) pastures deferred in the beginning of April 2009 is evaluated. Four pasture heights were evaluated at the beginning of deferment (10, 20, 30 and 40 cm). The experimental design consisted of completely randomized blocks with two replications. Rise in pasture height at the beginning of deferment decreased the appearance rate, increased the mortality rate and reduced the survival rate, the balance between appearance and mortality and the stability index of the tiller population at the beginning of the spring. Pastures deferred at initial height of 30 and 40 cm presented relatively stable tiller appearance rate between the beginning and end of spring. However, these pastures presented greater mortality rate, lower survival rate, lower balance between appearance and mortality and lower stability index of the tiller population at the beginning of spring when compared to rates at the end of spring. Pastures managed with shorter initial heights (10 and 20 cm) provided more tissue renewal in the subsequent growth season after their utilization in the winter.

O capim-marandu baixo no início do diferimento melhora a morfologia do pasto e aumenta o desempenho dos ovinos no inverno

“…Um modo de melhorar a morfologia do pasto diferido consiste na manutenção do dossel forrageiro baixo no início do período de diferimento (Sousa et al, 2012). Assim, há estímulo ao perfilhamento (Santana et al, 2014), isto é, ocorre maior aparecimento de perfilhos jovens no pasto, os quais têm alta relação folha/colmo. Dessa forma, o pasto diferido com menor altura pode ter morfologia mais favorável à seletividade do animal e, consequentemente, pode incrementar o desempenho animal em pastagens diferidas durante o inverno.…”

Sheep production during the rainy season in marandu palisadegrass swards previously utilized under deferred grazing

“…Forage production and, in fact, the stocking rate, may have been lower in the high pasture, due to the large amount of dead forage in the canopy, which may have limited tillering (Santana et al, 2014). Similarly, in the high/mowed pastures, tillering and forage production may also have been delayed at the beginning of the grazing period due to the high forage mass cut, which shaded the base of the plants.…”

“…It is possible that the large amount of dead forage from the previous winter has limited tillering in these pastures (Santana et al, 2014) and, consequently, reduced forage production. In fact, for the maintenance of at least two sheep per paddock, in order to measure the animal responses, the average height of the high pastures reduced to a level below the target.…”

“…This happened because the mowing promoted the elimination of much of the old forage, allowing the renewal of tillers in the pasture. Thus, there was more expressive participation of the young and vegetative tillers after mowing (Souza et al, 2015), which presented the greatest elongation and leaf appearance rates (Paiva et al, 2011), and has better morphological composition (Santos et al, 2010). On the other hand, the high marandu palisadegrass at the end of winter promoted greater shading at the base of the plants, inhibiting tillering (Santos et al, 2011); which generated a pasture with high percentage of dead tissues during spring and early summer (Souza et al, 2015).…”

“…However, deferred pastures with high forage mass at the end of winter may have their regrowth compromised in the spring due to shading at the base of the plants, which inhibits tilling (Santos et al, 2011;Santana et al, 2014). High amounts of stems and dead forage in late winter, common in deferred pastures, may also remain interspersed with spring regrowing plants, contributing to worsen pasture structure and hinder selective grazing of animals.…”