Alternaria Leaf Spot
Multiple Alternaria species
Alternaria leaf spot is a foliar disease of minor concern to NY growers. Foliar lesions are distinctive as brown spots surrounded by concentric rings, resembling a target. Numerous lesions may coalesce, causing defoliation. Severe infection may lead to pod infection and seed decay if harvest is delayed, and may be exacerbated by insect feeding on pods.
Because the disease usually doesn’t occur until very late in the growing season, it causes minimal yield loss and requires no management recommendations.