Indian Journal oj Agricultural Scie/ICes 64 (4) : 237..1), April 1994 Stability analysis for yield and component characters in ricebean (Vigna umbellata) V K DOBHAL 1 and N K GAUTAM 2 Regional Station, National Bureau of Plant Genetic Resources, Phagli, Himachal Pradesh 171004 Received: 16 November 1992 ABSTRACT An experiment was conducted during 1988-91 to study the stability parameters for yield and 3 component characters in 11 genotypes of ricebean [Vigna umbellata (Thunb.) Ohwi & Ohashi]. Genotype X environment (G X E) interaction was significant for pods/plant, clusters/plant, pod length yieldlp1ant. Both linear and non·linear components were predominant in G X E interaction for aU the characters, except for clusters/plant where linear component accounted for most of the G X E interactions. GenotyPes 'RB 49' (19.89 g/plant) and 'RB 40' (20.40 g/plant) were high yielding and most stable for aU the characters and could be utilized in a breeding progranune. No significant correlation was observed among the 3 stability parameters (mean, bi and SZ eli) for all the characters. These parameters may therefore be considered while breeding stable varieties of riccbean. Though work has been done on nutrition, evolution, taxonomy and cultural practices of ricebean [Vigna umbellata (Thunb.) Ohwi & Ohashi], information is meagre on the extent of its genotype x environment (G x E) interac- tion. The crop is highly sensitive to environ- ment fluctuations (Chandel et al. 1988), Hence an experiment was conducted to work Ollt the extent of G x E interaction to isolate high-yielding, stable genotypes that may be used either as a variety or as a donor parent in a breeding programme. MATERIALS AND METIIODS The material consisted of 11 genotypes of ricebean, viz 'RB 4', 'RB 56'; ·C X M 12 P 13', 'RB40', 'RB49', 'CxM8P2', 'RB26', 'RB 39', 'RB 17', 'RB 53' and 'RB 32'. These lScientist (plant Breeding), 2scientisL (Economic Botany) were grown in randomized blOCk design with 3 replications during the rainy seasons of 1988-91. The plot consisted of 3 rows of 10 plants each, with 15 em plant-to-plantspacing and 50 cm row-to-row spacing. The crop received a basal dose of 10 tonnes farmyard manure and 20 kg N/ha, and was grown in grovelled sandy-loam soil underrainfed con- dition. Data were recorded on 5 random com- petitive plants for clusters/plant. pods/plant, pod length and yield/plant at maturity. Average data of 5 plants were utilized for statistical analysis. The stability parameters were worked out as suggested by Eberhart and Russell (1966), RESULTS AND DISCUSSION Environment (Yea:J:)-wise analysis of variance revealed that significant differences existed among genotyPes under each environ- ment for clusters/plant, pods/plant, pod length 237