Effect of Urea, Yashil and Nitragin Fertilizers on Yield and its Components of Cowpea

This study was conducted to determine the application of biofertilizers, instead of chemical fertilizer, for optimal cowpea nutrition. It was performed in a factorial experiment based on Randomized Complete Block Design with three replications at Agricultural Research Center of West Azarbaijan, Iran during growing season of 2008-2009. Experimental treatments consisted of 4 rates of biofertilizers (without fertilizer , Yashil chemical fertilizer, Nitragine biofertilizer, Yashil+Nitragine) as factor A and 4 rates of nitrogenous chemical fertilizer( 0, 26.25, 52.5 and 75 kg/ha urea) as factor B. Analysis of the results showed that there were significant differences between rates of factor A (Nitragin biofertilizers + Yashil chemical fertilizer) and rates of chemical fertilizers and interaction between different levels of factor(A and B) for grain yield, number of grain per pod, number of grain per plant, number of pod per plant, 1000- grain weight and harvest index at 5% level of probability. It was also revealed that the effect of Yashil+Nitragine treatment was highly positive. The results showed that application 52.5 kg/ha urea highly increased on traits. The results obtained from interaction of different levels of factor AÍB indicated that application of 52.5 kg/ha urea and Yashil+ Nitragin combination had the highest effects on all traits. With regard to this results, it can be said that application of biofertilizers with chemical fertilizers had maximum increase in all traits under study.