This study investigated the effect of defoliation at emergence of cotyledons, 2 weeks and 4 weeks after planting on the number of nodules, nodule diameter, total nodule weight, nodule efficiency, root length and plant height of two improved varieties and one local variety of Vigna unguiculata (L.) Walp.__ampersandsignnbsp; efoliation treatments were carried out in triplicates using the CRD. Plants were raised in pots and data collected after 6 weeks. This study simulated early defoliation of the crop as evidenced in pest attack, disease infection and/or grazinganim als and significantly reduced nodule number (P__ampersandsignlt;0.001), nodule diameter (P__ampersandsignlt;0.002) and total nodule weight (P__ampersandsignlt;0.001). Change in nodule pigmentation was also observed. The effect of reduction in nodule characters was observed to culminate in a corresponding decrease in agronomic traits such as plant height (P__ampersandsignlt;0.001) and root length (P__ampersandsignlt;0.001). To reduce the effect of early defoliation on cowpea, farmers should plan the crop?s sowing so that its early growth stage would escape the season of dominance of its major defoliators.