Damage symptoms
Verticillium species mostly cause wilting of plants. The wilting starts at the lower leaves. These leaves are pale-green, then orange-yellow. In the beginning the plant seems to recover at night. The symptoms may occur only in parts of the plant. Cutting the stalk horizontally reveals a slight discolouration of the vessels, brown or greenish, but much less distinct than the discolouration caused by Fusarium. The root system usually stays mostly intact. In rose, branches die off from the top and purple brown stripes occur on the stem. In tomato, sometimes V-shaped lesions are formed on the leaf, between the veins. 'Early dying' disease of potato only occurs as premature senescence, without any other typical symptoms. In many crops, the fungus can be present without clear symptoms or with only partial wilting.
