Altura inicial e período de diferimento em pastos diferidos de capim-braquiária

• Autor(a) principal: Gouveia, Francisco de Souza
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5973
• topic: Manejo de pastagem; Brachiaria decumbens; Massa de forragem; Pasture management; Brachiaria decumbens; Herbage mass; CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL

This work was conducted with the objective of generating recommendations for initial heights and periods of deferment in Brachiaria decumbens cv. Basilisk evaluating its effects on herbage mass, pasture and structural characteristics of the interaction between. The experiment was conducted at the Forage Industry, Federal University of Viçosa, in Viçosa, MG, in the period from January to July of the years 2010 and 2011. Treatments consisted of three sward heights (10, 20 and 30 cm) at the beginning of deferment and three periods of deferment, and that in 2010 the durations were 171, 141 and 109 days in 2011 and 131, 100 and 71 days, arranged in split plot in a randomized complete block design with three replications. In plots (2 x 6 m) evaluated the deferment periods and, in the subplots (2 x 2 m), the sward heights initial. The variables evaluated were tiller density, herbage mass and its morphological components, heights and tipping index and volumetric density of morphological components. There was interaction between the deferral period and initial height of the pasture, in at least one of the experimental years, for the number of vegetative tillers, herbage total mass, mass of alive culm, dead blade mass, relationship between leaf blade masses alive and stem alive, plant height extended and volumetric at density alive blade leaf and alive stem. The pastures deferred for a short period had lower total forage mass (3.876 kg/ha de DM), of alive culm (942 kg/ha de DM), of dead leaf (785 kg/ha de DM) and culm dead (1.282 kg/ha de DM), greater number vegetative tillers (797 tillers/m²), lower number of reproductive tillers (2 tillers/m²), index lower tipping (1,4), upper mass alive leaf blade (655 kg/ha de DM) and high volumetric densities of blade leaf alive (24 kg/ha.cm de DM). The higher pastures at the beginning of the deferral had fewer vegetative tillers (431 tillers/m²), higher total forage mass (4.116 kg/ha de DM), leaf blade dead (968 kg/ha de DM), of dead stem (1.902 kg/ha de DM), higher the plant height extended (64 cm), and of pasture (41 cm). The resulting effects the deferral period and initial height of the pasture were of the same nature. The variation in the length of the deferral period influenced 100% of evaluated traits in 2010 and 85% in 2011. The use of long deferral period reduces the effects of sward height on the structure of signal grass. You can reduce the deferral period and increase the initial height of pasture B. decumbens to obtain forage mass similar to that obtained with greater adoption of the deferral period and lower sward height. Pastures B. decumbens cv. Basilisk deferred for use in July can be managed with periods of deferral 71-109 days and initial height of 20 to 30 cm. The initial height of 10 cm is recommended when taking longer deferral period.