Effect of climate variation on the yield of cowpea (Vigna unguiculata)

This research was conducted to study the effects of climate variables such as rainfall, temperature, and relative humidity on cowpea yield, and evaluated in Gombe State, Nigeria, during the period of 2009 to 2018 (one decade). The ex-post facto research design was adopted for the study, utilizing secondary data obtained from meteorological and agronomic data collected from the Metrological Office and agronomic data from the Ministry of Agriculture, Gombe State. Both data were collected and analysed using analysis of variance (ANOVA), Pearson Product Moment Correlation and Simple Linear regression. The study found that there is a negative relationship between rainfall, relative humidity and area of land/ha, while a positive relationship existed for temperature and cowpea yield over the period under study decade. The study revealed that all the parameters-rainfall temperature, relative humidity contributes 61% to climate variation in the study area. The study among others recommended that cowpea farmers should adopt new measures such as early planting, use of resistant varieties, contour farming to conserve water and supplementary irrigation to cope with the negative effects of climate change on cowpea yield and increases cowpea production in Gombe State, Nigeria. Key word: Climate variation, yield, cowpea.