The effect of interaction of chemical and biological fertilizers in different moisture regimes on the morphophysiological and grain yield of wheat

In order to study the effect of bio fertilizers and moisture regime on different moisture regimes on the morphophysiological and grain yield of Arg wheat cultivar, an experiment in the form of a split plot based on randomized complete block design with four replications was conducted at Zahak-Zabol Agricultural and Natural Resources Research Station during 2016-2017 crop year. Irrigation regimes were carried out on three levels as the main plots: irrigation after 45% (control) (S1), 65% (S2) and 85% moisture evacuation from soil (S3); biofertilizer sources were applied in seven levels: control ( F1), application of the locally common fertilizer, application of Azotobacter fertilizer along with the locally common fertilizer (F2), Azotobacter fertilizer with 50% of the locally common fertilizer (F3), Phosphabacter frtilizer with the locally common fertilizer ( F4), phosphabacter fertilizer with 50% of the corresponding chemical control fertilizer (F5), Azotobacter phospha-bacter fertilizer along with the locally common fertilizer (F6), and Azotobacter and phosphabacter along with 50% of the locally common fertilizer (F7), with all these seven serving as the subplots. The results showed the interactive effect of moisture regime and biofertilizer on the grain yield was significant at 1% level. This was such that in severe drought stress, biofertilizers with a mean of (6237 kg.ha-1) led to the grain yield increase of 38.8%, as compared to the control. Also, the improvement and increase in the 1000-seed weight, and biologic yield and harvest index were 27.6, 17.8 and 29.6 percent, respectively. Overall, the results of this study showed that in the irrigation under drought stress conditions at all stages of development, the use of Azotobacter and phosphabacter biofertilizers could have a positive effect on the grain yield, biologic yield, harvest index and leaf chlorophyll index, thereby improving the negative effects of drought stress.