EFFECT OF POTASSIUM FERTILIZERS ON THE QUALITY AND QUANTITY OF FOUR VARIETIES OF COWPEA CROP

Abstract

This experiment was conducted in the field of College of Agriculture –University of Diyala during the season 2013 to assess the performance of fourvarieties of cowpea (Black eye, Ramshorn, Local and Rhaoah) and the effect ofadding potassium fertilizer in the form of potassium sulfate of three levels ofpotassium (0.160, 320) kg h-¹ in the quality and quantity of yield by using splitplots in RCBD .The significance of differences between means were tested byusing H.S.D. test at 0.05 level of probability. The results of study showed asignificant difference in the performance of the varieties. The local variety wassuperior in plant yield, crop area and the average weight of pod highest valuesreached 1384.00 gm plant-1, 20.94 tons h-1 and 7.30 g respectively. The varietyof Rhaoah was superior in the average number and the length of pods and theratio of nitrogen and protein in seeds. The difference between varieties was notsignificant in the average number of pod seeds. The effect of adding potassiumfertilizer was significant. The addition of potassium level in 320 kg h-1 wassignificant in plant yield and crop area increase from the comparison in 24.47%and 24.75% respectively, in addition to the ratio of potassium in the seeds andthe number of pods. The level of comparison in the ratio of nitrogen and proteinin the seeds was superior. The interactions between varieties and potassiumlevels were not significant for all the varieties.