Disease

Bacterial leaf spot

Xanthomonas spp., Pseudomonas syringae

Bacteria carried on seed, transplants and debris that spread in splashing water and on hands and tools in wet foliage.

Signs

Warm, wet weather, splashing rain or overhead watering, and infected seed or transplants. Working among wet plants spreads it.

Buy clean seed, or hot-water treat it (tomato: 122 °F / 50 °C for 25 minutes; pepper: 125 °F / 52 °C for 30 minutes).
Inspect and buy disease-free transplants.
Do not handle or harvest plants when they are wet.

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.

Open in the key See plans

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?
Fruit, flowers or buds
What is wrong with the fruit or flowers?
Spots, patches or scabs on the skin
What do the marks look like?
Small raised scabby spots

Not a match? Start the key or describe what you see.

More from university Extension: search Extension pages on bacterial leaf spot, or find a plant diagnostic lab through your state's Extension.