Sustainable production of moth bean through genotype management under arid environments

Field studies were conducted during low (1995: 266.5 mm) and high (1996: 424 mm) rainfall years to evaluate the performance of early and late genotypes of moth bean (Vigna aconitifolia (Jacq.) Marechal) in a genocropping system (i.e. planting early and late genotypes together). Early (RMO-40) and late (Maru moth) flowering genotypes were planted as sole or mixed crops either within alternate or paired rows or mixture (1:1 by weight) of each genotype providing 100% or 50% plants of each variety in a plot. The crop performance, water use and water use efficiency were better during high as compared to low rainfall year due to more favourable soil moisture conditions. Furthermore, seed yield of early genotype when grown as sole crop was higher as compared to late genotype in the low rainfall year, but under the high rainfall situation late genotype performed better. However, when grown as mixed crop as alternate rows the seed yield was 2·5% and 42·9% higher than sole crops of early and late genotypes, respectively, under low rainfall conditions of 1995. During 1996 also the mixed crop provided higher seed yield than sole genotype, notwithstanding favourable moisture conditions. The improved performance of mixed crop, particularly under the low rainfall situation, could be attributed to more efficient use of water, low initial canopy development and higher photosynthetic rates. It has been concluded that for yield stability of moth bean, planting of early and late genotypes in a 1:1 ratio as alternate rows is most appropriate under low as well as high rainfall conditions.