Stability of blackgram (Vigna mungo L. Hepper) varieties for seed yield

Twelve blackgram varieties were evaluated for six seasons from Rabi 2009 to Rabi 2011 at Thrissur, Kerala, India to assess the genotype x environmental interactions. Analysis of variance on the data pooled over seasons showed significant difference between varieties, seasons and the interaction between varieties and seasons for days to flowering and yield. Flowering in blackgram was found to be influenced by photothermic index (PTI) rather than growing degree days (GDD). Rainfall received during the first three weeks after sowing had greater influence on seed yield. Analysis of genotype x environment interaction by AMMI model showed blackgram variety T9 as the best variety with respect to yielding ability suited for cultivation under favourable conditions. The varieties CO6 and TAU 1 with moderate yield capacity were found to be highly stable under differing environments and hence can be recommended for cultivation when prediction of environment is not possible.