Anthracnose on tomatoes

Anthracnose on tomatoes is a fruit disease, not a foliage disease. That distinction matters for management: the pathogen lives in soil and on plant debris, splashes onto fruit, and causes the lesions gardeners see when tomatoes begin to ripen and soften. Green tomatoes typically show no symptoms;.

Anthracnose on tomatoes is a fruit disease, not a foliage disease. That distinction matters for management: the pathogen lives in soil and on plant debris, splashes onto fruit, and causes the lesions gardeners see when tomatoes begin to ripen and soften. Green tomatoes typically show no symptoms; the same fruit develops circular, sunken spots days after it starts to color. By harvest time, a wet summer can turn a large portion of the crop to mush.

I don't grow tomatoes at my Long Island property, so this guide is sourced from University Extension research.

The pathogen

Tomato anthracnose is caused primarily by Colletotrichum coccodes, with some contribution from C. dematium. Per Penn State Extension, the pathogen overwinters in infected plant debris and in soil, where it can persist for multiple years. Spores are splash-dispersed from soil and lower plant surfaces onto developing fruit.