Effects of biofertilizers and iron nano‐oxide on maize yield and physiological properties under optimal irrigation and drought stress conditions

In this research, effects iron nano‐oxide and biofertilizers and chemical was investigated on the yield and some traits of Maize under normal and drought stress conditions in two years (2018 and 2019). The experiment was performed in the form of split–spilt plot in a complete random block design with three replications. The studied irrigation treatment included three levels (normal, 85% and 65% optimum water requirement) in the main plots and iron nano‐oxide at four levels (0, 0.5, 1, and 1.5 g/L) in subplots, and biofertilizers at four levels (noninoculation, inoculation with mycorrhiza, inoculation with pseudomonas and combined inoculation of mycorrhiza and pseudomonas) in sub‐plots. The results showed that grain yield, 1000‐grain weight, and leaf chlorophyll contents decreased by drought stress. Use of pseudomonas and mycorrhiza increased these traits in normal and stress conditions, but iron nano‐oxide had no significant effect on the measured traits. Also, drought stress increased malondialdehyde, ion leakage, catalase, peroxidase, proline, and polyphenol oxidase in both light and severe stress regimes. The amount of antioxidant enzymes increased under drought stress conditions in corn. The results indicated that all the characteristics measured by double inoculation with Pseudomonas and Microoriza had the best performance in conditions of water shortage and the use of these biofertilizers increases yield, 1000‐seed weight, and chlorophyll content of maize. Also, the use of biofertilizers modulates the effect of drought stress and reduces its negative effects.