EFFECT OF SALINITY ON YIELD AND YIELD COMPONENTS OF PINTO BEANCULTIVARS

A Factorial experiment based on randomized complete block design (RCBD) with three replications was conducted in 2010, to evaluate yield and yield components of three pinto bean cultivars (COS16, Talash and Khomain) under a non-saline (control) and three saline (4, 8 and 12 dSm-1 NaCl) conditions in the greenhouse. Ten seeds were sown in each pot filled with 900 g perlite, using 40 pots. After emergence, seedlings were thinned and 4 plants were kept in each pot. Mean number of pods per plant, 100 grain weight, plant biomass, grain yield per plant and harvest index decreased, due to salinity. Reduction in grain yield increased with increasing salinity. COS16 had more but smaller grains per plant, while Khomain produced less but larger grains, compared with other cultivars. Grain yield of Khomain was about 11.50% and 19.44% more than that of Talash and COS16, respectively. However, grain yield of Khomain and Talash was statistically similar. Pods per plant, 100 grains weight and plant biomass had significant positive correlation with grains yield per plant. The highest positive correlation was observed between 100 grains weight and grain yield, suggesting that the yield differences among pinto bean cultivars mainly resulted from differences in mean 100 grain weight. It was concluded that salinity can considerably reduce grain yield of pinto bean cultivars, but the extent of this reduction depends on the severity of stress and genotype.