Alternaria leaf blight of ginseng
The fungus causes an elongated brown lesion on the stem, which becomes velvety with spores as the disease progresses. Stems may become girdled by the lesion, which causes the top of the plant to wilt or topple over. Leaves may also become infected. Leaf lesions begin as watersoaked or oily looking spots or, depending on the environmental conditions, yellow spots that later enlarge and dry out in the center. Leaf spots are usually noticed when the centers of the lesions are tan or straw color and are bordered by a thin brown margin, which is surrounded by yellow tissue. Roots are not normally affected.