|Cowpea is a self pollinated crop, but however, out-crossing is higher than beans and groundnuts. The minimum recommended isolation distance for a seed crop is 20 metres. Where insect activity is expected to be high at least 50 metres isolation distance should be maintained. A crop of maize or sunflower may also be grown around the cowpea seed crop to reduce chances of contamination. To prevent admixture by volunteers from previous crops the land should not have had a cowpea crop in the previous two seasons.