the effects of simultaneous application of different organic and biological fertilizers on quantitative and qualitative characteristics of cucurbita pepo l.

understanding of relations and interactions between ecosystem’s components and plants is one of the main conditions for sustainable production of medicinal plants. to study the effect of simultaneous application of organic and biological fertilizers on yield and yield components of zucchini squash, a split plot arrangement of factors based on randomized complete block design with tree replications was used during 2009-10 growing season. the mainplot factor was the type of organic fertilizers, including 1-cow manure, 2-sheep manure, 3-chicken manure, 4-vermicompost and 5-control. the subplot factor was the biofertilizer (namely nitragin, containing azotobacter sp. , azospirillum sp. and pseudomonas sp.), utilization. the results showed the positive but non significant effect of organic and biological fertilizers on yield and yield components of zucchini squash. amongst the organic fertilizers, cow and chicken manure, have superiority compared the others. the highest seed oil and protein percent resulted in chicken manure, although there was not significant different between treatments due to seed oil percent. the positive effect of organic and biological fertilizers on seed yield was higher than fruit yield. positive correlations found between fruit and seed yield, and between one fruit weight and one fruit seed weight (r2=0.72** and 0.56**, respectively). at a glance, cow manure solely application was better than its application with nitragin. nitragin application has no significant effect on some traits, when utilized with sheep manure and vermicompost. the possibilities of antagonistic effect among organic and biological fertilizers needs to be more studied.