Yield and growth characteristics of sunflower cultivars inoculated by arbuscular mycorrhizal fungi under drought tension conditions

One of the new methods for optimum management and increasing the efficiency of water resources utilization in agricultural uses is the use of irrigation methods. Considering the importance of this issue, this research was carried out to determine the effect of mycorrhizal fungi on the yield of sunflower cultivars under drought tension conditions and as split split plots based on randomized complete blocks design with three replications in 2016.The applied treatments included drought tension levels: severe tension, moderate and non-tension, three cultivars of sunflower Farrokh, Hissan and Barzegar, and two species of mycorrhizal fungi Glomus mossea and Glomus intraradices. Different levels of soil moisture discharge (80, 60 and 40 percent, respectively) were considered for applying different treatments. Different irrigation treatments were applied after stem elongation and then the growth and yield characteristics were measured. The results showed that application of mycorrhiza had a significant effect on the increase in seed and oil yield of sunflower cultivars, stem dry weight, stem length, seed number and diameter. The highest grain yield was obtained from using Hissan cultivar and G. mossea fungi under moderate drought tension conditions (6399/05 kilogram per hectare). Extreme and moderate drought tension without mushroom application caused 46 percent and 20 percent loss of yield of sunflower cultivars compared with control (non-tension conditions without fungi use). Moderate drought tension and application of mycorrhiza Arbuscular fungi reduced 13 percent of sunflower seed yield to full irrigation, saving only irrigation water by 30 percent compared to full irrigation. Therefore, it was concluded that the use of arbuscular mycorrhiza fungi can compensate for the loss of yield resulting from drought tension through water saving.