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.