Application of fungicides interferes with plant-mycorrhiza symbiosis and inhibits root system development, absorption and growth. So this experiment was conducted in 2009 at the research field of Islamic Azad University, Karaj branch, Iran, to evaluate the effect of different fungicides on mycorrhizal symbiosis and quality of sunflower. The study was conducted in factorial in the form of a randomized complete block design with four replications and two factors. The first factor was fungicide (without, F0; chemical, F1; nano, F2; biologic, F3) and the second factor was mycorrhiza species (without, M0; Glomus mosseae, M1; G. etunicatum, M2; G. intraradices, M3). Results indicated that fungicide had only a significant effect on grain protein content, and mycorrhiza had a significant effect on grain oil content and root colonization. F2M1 was the best treatment with the highest effect which increased grain yield, protein yield and oil yield by 60.77, 60.93 and 69.90%, respectively, compared with the control (F0M0).
