Interactive effect of biocontrol agent Microdochium bolleyi on take-all disease (Gaeumannomyces graminis) in the soil treated with phosphorus and nitrogen fertilizers

Take-all is one of the most important wheat diseases worldwide. The present study assessed the effect of nitrogen and phosphorus fertilizers, and endophytic fungus Microdochium bolleyi on controlling this disease in wheat ‘Pishgam’ cultivar for the first time. A greenhouse experiment was conducted based on a completely randomized design (CRD) with the treatments of control, nitrogen+phosphorus fertilizers (100 and 200 mg kg-1 urea, and 50 and 100 mg kg-1 triple superphosphate) alone and their combination with pathogen Gaeumannomyces graminis and endophytic fungus M. bolleyi. Then, root dry and shoot fresh weights, plant height, and leaf chlorophyll content, as well as the percentage of root contamination were measured. Based on the results, root dry and shoot fresh weight, plant height, and leaf chlorophyll content were significantly maximized following the treatments containing urea and triple superphosphate at various levels, and endophytic fungus (p<0.05). In terms of pathogenesis control, about 46% decrease was observed in take-all disease for the treatment receiving urea+triple superphosphate alone. The disease was respectively controlled by around 58 and 75% after applying endophytic fungus M. bolleyi alone and in combination with the highest amount of urea+triple superphosphate, respectively.