Biology
Anthracnose of lettuce is a fungal disease favored by cool, wet weather. The disease is also known as shothole because of the characteristic symptoms. Lower leaves develop small, water-soaked spots which quickly darken and enlarge. The centers dry and drop out, leaving "shotholes" with black margins in the leaves. Affected leaves tend to wither and die quickly, then break off. The disease progresses to the younger leaves and may also cause symptoms on the midribs. The fungus is spread by splashing water and can be serious during prolonged wet weather. Some weed species are also hosts of the fungus.
|
