Effect of Phosphorus Application Rate on Growth and Yield Performance of Cowpea Varieties

This research was conducted to evaluate the effect of phosphorus application rates on growth and yield performance of two cowpea varieties (FUAMPEA 3 and SAMPEA 14) at ICRISAT farm, Bayero university kano. The experiment was laid out in a randomized complete block design (RCBD) with three replications, incorporating three phosphorus levels (0, 20, and 40 kg/ha) and two cowpea varieties. the result from this research showed that phosphorus application had a highly significant (p < 0.01) effect on several growth parameters such as relative chlorophyll content, leaf area, and active nodules, as well as on yield parameters including field dry weight, root weight, total dry matter, and grain yield. The 40 kg/ha phosphorus rate consistently resulted in superior performance, with grain yield reaching 1521.36 kg/ha and chlorophyll content at 79.74 SPAD units. FUAMPEA 3 outperformed SAMPEA 14 in yield (1265.52 kg/ha) and root traits, while SAMPEA 14 recorded higher nodulation. However, interaction effects between phosphorus levels and varieties were not significant (p > 0.05), suggesting uniform response patterns across varieties. Overall, the result from this research highlights the importance of phosphorus fertilization, particularly at 40 kg/ha in enhancing cowpea productivity, and supports FUAMPEA 3 as a variety with higher yield potential under optimal phosphorus conditions.