The present research was conducted to study the effects of mycorrhiza and different phosphorus levels on yield of sunflower (Progress cultivar). The field experiment was conducted as a factorial design based on a randomized complete block with eight treatments and three replications in Boyerahmad area of Iran in 2012. The treatments including two levels of mycorrhiza (Glomus intradices) M1and M0 (with and without mycorrhiza) and four levels of triple phosphorus (TP) (0, 50, 100 and 200 kg/ha) applied through triple super phosphate fertilizer. The results showed that, application of mycorrhiza had significant effect on the seed yield, Biological yield and seed hollownes. The application of phosphorus fertilizer showed statistically significant effect on the seed yield, Biological yield and 1000-seed weight. The highest seed yield (2372.2 kg/ha) of sunflower was recorded with the application of 0 kg P/ha with application of mycorrhiza treatment (M1P0). The treatment combinations of M1P200 and M0P200 did not show significant different in terms of seed yield of sunflower. The highest Biological yield (35806 kg/ha) was obtained by M1P0 and lowest Biological yield (21317 kg/ha) was observed in M0P50. The lowest rate of seed hollowness percentage (6.68 percent) was obtained by M1P0 without significant difference with M0P100 treatment.
