Effects of Mycorrhizal Fungi and Different Levels of Phosphorus on Growth of Zea mays L. under Water Stress Condition

Nowadays، mycorrhizal fungi are widely used due to their symbiosis relation with roots of so many plants. By facilitating absorption of some plant minerals and water، these fungi have a key role in all ecosystems. In this research، the effects of mycorrhizal fungi and different levels of phosphorous chemical fertilizers on some yield components and macro elements uptake of Zea mays L. under different levels of irrigation water were studied. The experiment was performed in completely randomized block as a split factorial design with four replications using different irrigation levels (A1=60، A2=120، A3=180 mm of evaporation from class A pan) as the main plots and different P levels (P1=0، P2=60 and P3=120 kg P/ha on the basis of P2O5) and mycorrhizal fungi (at two levels: un-inoculated and inoculated with 6 g of mycorrhizal inoculant placed 3 cm under each seed) in the subplots. The results indicated that the effects of Mycorrhizal inoculation were significant and positive on measured indices. Among triple interactions i. e. irrigation/ chemical phosphorus/ mycorrhizal inoculation، significant effects (p<0. 05) on grain yield (maximum 5045 kg/ha) and 1000 seed weight (157. 75 g) and also on P concentration (p<0. 01) were observed in treatments with proper amount of water and fertilizer P and mycorrhizal inoculation (A1P2G2). Under water stress، the highest grain yield، 1000 seed weight، fresh forage، and P concentration were obtained in treatment with moderate water stress and proper amount of chemical P (60g/kg) and mycorrhizal inoculation (A2P2G2). Also، the highest plant height (242. 87 cm) was obtained in the same treatment. Results showed that in moderate water stress، using proper amount of chemical P and mycorrhizal inoculation can compensate decrease in grain yield، while under high level of drought stress، grain yield decreased.