RICEBEAN [Vigna umbellata (Thunb.) Ohwi and Ohashi] LANDRACES OF NAGALAND IN DIFFERENT ENVIRONMENTS

Stability of yield and its attributes were assessed for 13 landraces genotypes of Rice bean over six environments during Kharif season 2016 and 2017, on six different growing seasons, to determine the quantitative responses of different Rice bean genotypes at six different environments. The combined analysis of variance revealed highly significant differences among Genotypes (G), Environment (E) and interactions of Genotypes and environments(G x E) for most of the studied traits. The joined regression analyses of variances due to environment (linear) were highly significant for characters like Days to 50% flowering, number of pods per plant, 80%maturity, 100 seed weight and seed yield per plant under study, which indicated the genetic control of response to the environment. The variance due to GxE (linear) was significantly different for 50% flowering, pod length, number of seeds per pod and 100 seed weight and non-significant for days to primary branches, pods per cluster, number of pods per plant, plant height, number of primary branches per plant, number of pods per plant, number of seeds per pod, 80% maturity and seed yield per plant. It indicated the differential response of varieties to various growing season. Varieties RbnG3, RbnG5, RbnG8, RbnG9 and RbnG12 showed higher seed yield, regression coefficient equivalent to unity and deviation from regression equivalent to zero. It indicated that these varieties were suitable for cultivation on a wide range of environments as these had greater stability along with high yield