Evaluation Effect of Copper Foliar Application at Different Growth Stages of on Seed yield and Its Components of Cowpea (Vigna Sinensis L.)

Nutrients play a very important role in chemical, biochemical, physiological, metabolic, geochemical, biogeochemical, and enzymatic processes.
This research was done to assess the effect of different concentration and stage of foliar application of Copper on seed yield, yield components and harvest index of Cowpea.
This research was carried out via factorial experiment based on randomized complete blocks design with three replications along 2017 year. The treatments included different concentration of Copper foliar application (a1: none use of copper or control, a2: 150 gr.ha-1, a3: 300 gr.ha-1, a4: 450 gr.ha-1) and Copper foliar application at different growth stage (b1: apply at vegetative stage, b2: beginning of flowering stage, b3: beginning of pod formation). This experiment had 36 plots.
Result of analysis of variance revealed effect of different concentration and growth stage of foliar application of Copper on all measured traits was significant but interaction effect of treatments was not significant (instead number of pod per plant, seed yield and biologic yield). Mean comparison result of different concentration of foliar application of Copper indicated that maximum amount of number of pod per plant (14.83), number of seed per pod (11.96), seed weight (23.65 gr), seed yield (211.61 gr.m-2), biologic yield (509.19 gr.m-2), harvest index (41.55%) was noted for 300 gr.ha-1 Copper (Also it doesn’t have significant difference with 150 gr.ha-1 Copper) and minimum of those belonged to control treatment. As for Duncan classification made with respect to different growth stage of foliar application of Copper the highest amount of number of pod per plant (14.18), number of seed per pod (12.04), seed weight (23.41 gr), seed yield (206.01 gr.m-2), biologic yield (518.75 gr.m-2), harvest index (40.75%) belonged to vegetative stage and lowest ones was for beginning of pod formation.
Finally based on result of current research according economic aspects use of 150 gr.ha-1 of copper foliar application in the vegetative stage at studied region is advised to producers.