Effect of Water Deficit on Seed Yield and Accumulation of Seed Minerals in Common Bean Genotypes

This research was conducted to evaluate the impact of field water deficit on quality and accumulation of some mineral nutrients in the bean seeds. Field experiment was carried out as split plot based on RCBD with four replications in Seed and Plant Improvement Institute, Karaj, Iran, in both normal irrigation and water deficit conditions as main plots and eight bean genotypes (red beans: KS31163, KS31164 and KS31170; white beans: KS41237, KS41107; Chitti beans: KS21478, KS21486 and KS21489) as sub plots, in 2009 and 2010 cropping seasons. Seed yield and accumulation of nitrogen, iron, zinc and phosphorus in the seeds were assessed. The results indicated that seed yield and minerals were reduced by water deficit. Genotype KS31163 had the highest seed yield under both irrigation conditions. The impact of drought on iron and phosphorus was more than on zinc and nitrogen. The highest Fe reduction was assessed in red bean genotype KS31170. The white beans showed lower levels of Fe and N in the seeds than red and Chitti beans under water deficit conditions, while stored more phosphorus amounts. In both conditions, KS21478 and KS41237 genotypes had the highest and the lowest amount of zinc, respectively. The greatest impact of water deficit was related to the iron accumulation in the seed, averaging more than 19 percent. Overall, water deficit decreased the concentration of mineral nutrients in the seeds. The cumulative amount of minerals in the seeds of KS31170, KS21478 and KS31163 were more than other genotypes under both irrigation conditions.