Farmers keep trying to avoid using chemical fertilizer without losing high yield. A field experiment was conducted in the fields of Agriculture College, University of Baghdad during winter seasons of 2015 and 2016 to investigate the response of three bread wheat (Triticum aestivum L.) cultivars (Ibaa99, Abu-Ghraib3 and Buhooth22) to the frequency of spraying with biofertilizer (EM-1) (one time at tillering stage, twice at tillering and stem elongation stages and three times at tillering, stem elongation and booting stages) in addition to the control (without spraying), to the increase of grain yield. Randomized complete block design (RCBD), in split plots arrangement and four replications, was used. Spraying treatments were placed as main plots and cultivars as subplots. The results showed that Ibaa99 cultivar, three times of EM-1 spraying and their interaction gave the highest averages of grain yield (3.89 and 4.31), (3.85 and 4.36) and (4.11 and 4.58 ton*ha-1), respectively, for both seasons. It can be concluded that yield responded significantly to the frequency of EM-1 spraying during vegetative stages.
