Effects of Supplemental Irrigation and biofertilizers on Yield and Yield Components of Dryland wheat (Triticum aestivum L.)

The effects of supplemental irrigation and biofertilizers on yield and yield components of Sardary wheat cultivar, were studied by an field experiment as split plot based on randomized complete block design at Research Station of the University of Kurdistan in 2013-2014 growing season. Factors consisted of three irrigation levels: without irrigation, irrigation at flowering stage and irrigation during grain filling were assigned to the main plots, and five fertilizer levels: Nitrokara biofertilizer, Phosphate Barvar2 biofertilizer, Nitrokara + Phosphate Barvar2 biofertilizers, Nitrokara + Phosphate Barvar2 biofertilizer + 50% chemical fertilizer and 100% chemical fertilizer were allocated to subplots. The results of analysis of variance showed that the effect of irrigation was significant on dry weight, plant height, and spike length, number of spike per unit area, seed number per spike, 1000-grain weight, grain yield, and seed protein content. Integrated application of biological fertilizer (Nitrokara and Phosphate Barvar2) along with chemical fertilizers produced the highest seed yield (319.9 g.m-2). The lowest grain yield was obtained from Nitrokara (227.3 g.m-2) treatment. Our results showed the positive impact of irrigation at flowering and grain filling stages and inoculation of biological fertilizers (Nitrokara and phosphate Barvar2) with 50% chemical fertilizer on dry weight, number of seeds per plant, 1000-grain weight and grain yield. Integrated application of biological and chemical fertilizers while meeting the nutritional needs of the plant and incresing seed yield, could significantly reduce the use of chemical fertilizers. According to the results of this experiment, a supplementary irrigation during flowering or seed filling stage was effective in increasing the yield of rainfed wheat.