Plant Problem Diagnosis Key / Diseases
Disease
Verticillium wilt
Verticillium dahliae, V. albo-atrum
A soil fungus with hundreds of hosts that blocks the water tissue. Unlike Fusarium it prefers cooler soil, and it survives up to 10 years as tiny resting bodies.
Signs
- V-shaped yellow wedges at the leaf edge on lower leaves, turning brown.
- Wilting in the heat of the day, lower leaves first.
- Tan to brown streaks in the stem's water tissue, usually lighter than Fusarium's.
What favors it
Cool soil and moderate temperatures, ground recently in potato, tomato, eggplant or strawberry, and some weeds.
Prevention
- Grow resistant varieties (V on tomato packets).
- Rotate 4-5 years to non-host crops, such as non-susceptible grasses.
- Do not plant susceptible crops after potato, tomato, eggplant, strawberry or raspberry.
Often confused with
Sources
- Verticillium Wilt of VegetablesUniversity of Maryland Extension
- Verticillium Wilt of Tomato and EggplantNC State Extension
Treatment by crop
Cultural, biological and chemical options in the order to use them, and notes written for each crop.
Identification is free. Treatment is on the Home and Pro plans.
Questions in the key that lead here
- Look the plant over, leaf undersides included. Are insects, mites, slugs, eggs, webbing or droppings on it?
No, only damage or discoloration - Where is the problem?
A tree or shrub - Which part of the tree or shrub shows the problem?
Branches dying, or the crown thinning - How is the dieback showing?
One or a few branches wilt, yellow or brown all at once - Which tree is it? Peel the bark off a wilted branch and look at the outer wood.
Maple, redbud, catalpa, smoke tree or another tree, with olive or green streaks
Not a match? Start the key or describe what you see.
More photos
More from university Extension: search Extension pages on verticillium wilt, or find a plant diagnostic lab through your state's Extension.
Other diseases
- Anthracnose
- Apple scab
- Bacterial leaf scorch
- Bacterial leaf spot
- Bacterial wetwood (slime flux)
- Bacterial wilt of cucurbits
- Black knot
- Black spot of rose
- Bleeding canker
- Boxwood blight
- Canker diseases
- Cedar-apple and related rusts
- Crown gall
- Damping-off
- Downy mildew
- Dutch elm disease
- Early blight and Alternaria leaf spot
- Elm yellows (phloem necrosis)
- Fire blight
- Fusarium wilt
- Gray mold (Botrytis)
- Late blight
- Mosaic viruses
- Needle cast and tip blight
- Oak wilt
- Powdery mildew
- Root and butt rot
- Root rot (Pythium and Phytophthora)
- Rust
- Septoria leaf spot
- Shade tree anthracnose
- Sooty mold
- Tar spot of maple
- Tomato spotted wilt and impatiens necrotic spot viruses
- White mold (Sclerotinia)
- White pine blister rust