What is Black dot (disease)?

Black dot disease is caused by the plant pathogen known as Colletotrichum coccodes. It affects all underground parts of the potato, including the roots, tuber, and stolon. C. coccodes is also able to infect the stem and foliage of the potato plant. It can be introduced into an area by planting an infected tuber, and then spreading to other plants. A sign of black dot disease is black microsclerotia that are produced by the pathogen, and can be found on the roots, the tuber, the stems, and the leaves. This can be used to diagnose black dot. Symptoms of black dot disease include silvery lesions on the surface of the tuber, brown or black lesions on the leaves, leaf wilting, and chlorosis.