How to Manage Pests
Pests in Gardens and Landscapes
Downy mildew—Peronospora pisi
Pea plants with downy mildew have white and purple cottony growth on the undersides of leaves. The tops
of leaves have yellow blotches. Pods may have dark spots. Affected parts may be water soaked.
Downy mildew is caused by a soil or seedborne fungus. It is favored by low temperatures and moist conditions,
especially fog. The best way to prevent downy mildew is to avoid the environmental conditions that favor
it. Freely circulating air, allowing plants to dry between irrigations, and keeping leaves as dry as possible
are good ways to limit the disease. Adjusting planting times may help in some areas. Always destroy infected
crop debris and susceptible related weeds before planting a new crop. Some varieties may show resistance.
growth of downy mildew
blotches on upper pea leaf surface