Powdery mildew

Symptoms consist of a light, greyish, powdery growth on the leaves, pods and occasionally the stems. This powdery growth is easily rubbed off. When the disease is severe, plants turn yellow and defoliate. Generally, powdery mildew does not damage early-planted cowpeas. It can, however, be quite destructive on a late-planted crop. A fairly dry soil and heavy application of nitrogen-based fertiliser tend to increase disease severity.