Verticillium wilt on tomatoes

Verticillium wilt and Fusarium wilt are the two most common soilborne wilts of tomatoes, and they are often confused. The practical difference matters: Verticillium strikes in cooler soils and causes a slower decline than Fusarium, and the two diseases warrant different rotation and variety.

Verticillium wilt and Fusarium wilt are the two most common soilborne wilts of tomatoes, and they are often confused. The practical difference matters: Verticillium strikes in cooler soils and causes a slower decline than Fusarium, and the two diseases warrant different rotation and variety selection strategies. Getting the diagnosis right determines whether the resistant cultivar you choose next season will actually protect the plant.

I don't grow tomatoes on my Long Island property, so this guide draws on University Extension publications and USDA pathology resources.

The pathogen

Verticillium wilt of tomato is caused primarily by Verticillium dahliae, with some contribution from V. albo-atrum in cooler regions. Per Cornell Cooperative Extension, V. dahliae is a soil-inhabiting fungus that infects host plants through roots and colonizes the vascular system, blocking water transport.

Unlike Fusarium oxysporum, which is host-specific, V. dahliae infects a very wide range of hosts including tomato, eggplant, pepper, strawberry, potato, and numerous ornamental shrubs. Per UC IPM, more than 200 plant species are susceptible to V. dahliae.