MAXIMIZE UTILIZATION OF SOME ORGANIC FERTILIZERS TO PRODUCE THE HIGHEST YIELD OF COWPEA.

Two field experiments were established in middle Nile delta alluvial soils. The study was conducted on the two successive summer seasons of 2016 and 2017 in the experimental farm of Tag El-Ezz Agricultural research station, Agricultural research center (ARC), Dakahlia governorate, Egypt. The experiment was laid out in a split plot design with three replications, assigning nine treatments to study the effect of three forms of organic fertilization (without, farmyard manure and compost rice straw) as main plot, and 3 forms of foliar application (control, mix of micro nutrients (Fe, Zn and Mn) and humic acid (HA)) as sub plot on growth, yield and chemical constituents of cowpea (Vigna unguiculata L.). The obtained results showed that, addition of organic amendments in forms of compost rice straw significantly increased plant growth parameters (plant height, fresh weight, dry weight and number of leaves), chemical composition of leaves (chlorophyll a, b and total chlorophyll content, N, P, K, Fe, Zn and Mn as well as quality parameters (C. protein, T. carbohydrates, C. fiber, ash and total sugar of cowpea seeds except with moisture conetnt) and yield as well as its components (No. of pods/plant, No. of seed/pod, 100 seed weight and seed yield, also availability of soil (N, P and K). On the other hand; mix of micro elements gave significant positive effect and higher average values for all parameters previously. The interaction effect between organic fertilization and foliar application show a primitive effect on all parameters and the highest mean values of parameters was recorded with using CRS as organic fertilization and mix of micro nutrients as foliar application.