Effects of water deficit on nutrient content and grain protein of bread wheat genotypes

Plant nutrient uptake from the soil is dependent on soil moisture, fertilizers applied, soil chemicals and some other environmental factors. The objective of this study was to gain a better understanding of how water deficit affects grain yield and quality of bread wheat genotypes. Two field experiments were conducted at the Agriculture Research Station of Miandoab in West Azarbayjan during 2007-2008 and 2008-2009 to examine the effects of water supply (irrigation after I-1 = 70, I-2 = 100, I-3 = 130 and I-4 = 160 mm evaporation from Class-A pan) on macronutrients concentrations, protein content and grain yield in 10 winter wheat genotypes (Zarrin, Alvand, Shahryar, Sardari, C-80-4, C-81-10, C-81-4, C-83-3, C-83-8 and C-84-9). Irrigation and genotypes showed significant differences in grain yield and protein and macronutrients concentrations. Grain yield and macronutrient concentrations (K, Ca and Mg) in all genotypes decreased, but protein and P concentrations of grains increased with decreasing water availability. Macronutrients such as N, P and Ca in shoots decreased, but K and Mg increased as water supply was limited. These results suggest that wheat genotypes respond differentially to water deficit and macronutrients. The highest grain yield per unit area under well-irrigated and severe water deficit was obtained for Zarrin and C-84-9 genotypes, respectively.