EVALUATION OF HARVESTING TIME ON SEED YIELD AND QUALITY OF Brachiaria brizantha

Abstract

The study assessed the effect of harvest time after anthesis on Brachiaria brizantha cv. Marandu seed yield and quality. The experiment was conducted under rain fed conditions during 2007, at the Experimental Research Unit, Universidad del Papaloapan, Loma Bonita, Oaxaca, Mexico. Treatments were seven harvest times, at 4, 8, 12, 16, 20, 24 and 28 days after anthesis (DAA), distributed in a completely randomized block design with four replicates. Variables evaluated were: total seed yield (TSY), pure seed yield (PSY), panicles/m(2), panicle length, harvested spikelets per panicle, 1000 seed weight, spikelet abscission rate, seed purity and germination. Harvest time had a positive effect (P<0.001) on TSY and PSY (P<0.05), where the highest values (149.2 and 38.4kg.ha(-1)) were observed for seed harvested at 24 DAA. Number of harvested spikelets per panicle was the variable more closely associated to TSY, with r=0.45. Spikelet abscission rate and seed germination percentage showed differences among treatments (P<0.05). It can be concluded that the largest seed yield was obtained at 24 DAA, once 27\% of spikelets had been shed.