Carrot: Leaf spot
Photo by: R.S. Byther
Biology
Leaf spot of carrot is also known as early blight. It is a fungal disease. The disease produces leaf and stem spots, primarily attacking young leaves. Initially the spots are small, with yellow halos or margins. Older lesions may become tan or light gray as the fungus produces spores on the infected tissues. Severe infections may result in death of leaves.
Disease spores can be spread by wind. The fungus primarily overwinters in diseased plant material. Leaf spot may be confused with leaf blight, which generally attacks older foliage.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Rotate crops. Allow two or three years between carrot crops in a given location.
- Plant in well-drained soils.
- Schedule watering so that carrots are dry by night.
- Remove plant debris from the garden. Destroy or discard (do not compost) diseased materials.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
- Apply when plants are 6 inches tall or when disease threatens.
- Repeat at weekly intervals if necessary.
Approved Pesticides
If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.