Estacionalidade e estabilidade de produção de forragem de progênies de Brachiaria ruziziensis

Abstract

The objective of this study was to evaluate the forage biomass productivity of Brachiaria ruziziensis progenies and yield stability over different cuts, representing favorable and nfavorable periods of forage development. 118 progenies of B. ruziziensis and the controls B. decumbens cv. Basilisk, B. brizantha cv. Marandu, B. ruziziensis cv. Common and Brachiaria sp. were evaluated using a randomized block design with two replicates. There were seven cuts assessment with an average interval of 60 and 90 days in water (5 cuts) and dry (2 cuts) seasons. In each cut, plants height (ALT) and dry (PBS) and green (PBV) biomass forage yield were measured. The averages of the different cuts made in dry or water seasons were used to perform statistical analysis in a factorial (progeny x times) for the effects of progeny production seasonality. The stability analysis also was performed. Despite the large concentration of PBV and PBS in the rainy season, the existence of genetic variability between progenies of B. ruziziensis for ALT, PBV and PBS were observed in both rainy and dry seasons. Some evaluated materials showed production stabilities higher than commercial cultivars of Brachiaria indicating the possibility of identification and selection of B. ruziziensis material with higher average and stable production over the year.