Problem type: Disease
Name of problem: Verticillium Wilt
Plant name(s): Woody and herbaceous plants, including fruit and vegetable crops
Symptoms / Characteristics:
Verticillium wilt is caused by the soil borne fungi Verticillium dahliae and V. albo-atrum. The pathogen usually attacks lower leaves first and progresses upward. Common symptoms include interveinal discoloration, wilting, defoliation and death. Woody ornamentals may also exhibit thin crowns with small leaves and poor annual growth. Infected vegetable crops often have V-shaped lesions or yellowing patterns, which taper inward from the leaf edge. Because the fungus attacks the vascular system, only one side of a leaf, branch or plant may exhibit symptoms. Infected wood may have dark streaks or bands that follow the grain and can be made visible by cutting into the stem or wood.
Elm is among a long list of woody ornamentals that are susceptible to this fungal pathogen. Because wilting is often associated with Dutch Elm Disease, it is important to look for other diagnostic symptoms of verticillium wilt.
Control / Preventions:
Use ornamental and food crops that are resistant to the disease and avoid using plants that are known to be susceptible. There are many ornamentals that exhibit resistance including pine, spruce, crabapple, birch and dogwood. Use disease free vegetable seed and a recommended pre-planting fungicide seed treatment. Keeping plants healthy with regular watering and an adequate fertility program is the best method of prevention. There is no domestic chemical control.