Problem Identifier Unit Screen//v.w/ RR Template

Problem Identifier Unit Screen//v.w/ RR Template Bean Anthracnose

Problem
Small brown specks on pods enlarge to black, circular, sunken spots. In wet weather, a salmon-colored ooze appears in the infected spots. Elongated dark reddish brown spots appear on the stems and veins on the underside of the leaves. If seedlings are attached, the stems may rot, or the first young leaves may be spotted. In either case, the seedlings die.

Analysis
This bean disease is caused by a fungus (Colletotrichum lindemuthianum) that affects all kinds of beans, but is most destructive on lima beans. It occurs in the eastern and central states, rarely west of the Rocky Mountains. The fungus thrives in cool, wet weather. The salmon-colored ooze that often appears in the infected spots during wet weather consists of slime spores. The spores are carried by splashing water, animals, people, or tools to healthy plants. The fungus lives on diseased bean seeds and on plant debris that has been left in the garden.

Solution
Apply a fungicide containing chlorothalonil at flowering and repeat 3 more times at intervals of 7 to 10 days. Continue treatments whenever wet weather occurs. Remove and destroy any diseased plants. The disease spreads rapidly on moist foliage, so do not work in the garden when the plants are wet. To avoid reintroducing this fungus into your garden, purchase seeds from a reputable seed company. Do not plant beans in the infected area for 2 or 3 years. Rotate your bean planting site every year.

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