Cropping systems in farmland areas of Iran are characterized by consumption of chemical fertilizers (C) leading to serious erosion and fertility decline. Information regarding the influence of bio, organic fertilizers (O) and C on pumpkin traits is not available. Therefore, a field experiment was conducted at research farm of Kurdistan university in 2009. Fourteen compositions of bio, O and C were done as treatments. Results indicated that the maximum seed yield (118.5 g m-2), oil yield (43.31 g m-2) and fruit yield (6056.2 g m-1) were obtained with treatment that pumpkin seeds inoculated with free-living nitrogen fixing bacteria (NO) and phosphate solubilizing bacteria (PO) + 50% organic fertilizer. Oil percentage responded to fertilizer treatments and the maximum oil percentage (48.15%) was obtained at treatment that pumpkin seeds inoculated with PSB + 50% chemical fertilizer. The fertilizer treatments had no significant effects on the 1000 seeds weight and fruit number per plant. It is concluded that application of biofertilizers with 50% chemical and organic fertilizers (CO), reduced the need for C and produced higher oil, seed and fruit yield.
