Plant Doctors Offer Tomato Tips to Banish Blight

St. Paul, Minn. (June 23, 1998)—Dreaming of a BLT made with vine-ripened tomatoes from your garden? Or how about colorful cherry tomatoes garnishing your summer salads? America's plant doctors, members of the American Phytopathological Society (APS), offer guidance for growing terrific tomatoes.

"There are several important practices to keep in mind that will ensure a healthy and bountiful crop," says Thomas Zitter, plant doctor and research scientist at Cornell University and an APS member. "The key is to initiate steps that will help eliminate infection by fungal blights that can limit the quality and abundance of fruits or sometimes totally destroy the plant."

To banish blights, follow these tips from the APS plant doctors:

Water only at the base of the plant and early in the day. Long periods of moisture on foliage encourage blight.
Stake plants and remove suckers to increase air movement through the plant and to reduce moisture on the foliage. Staking also improves fruit quality and helps prevent root rots.
Mulch to keep plants evenly moist and to reduce watering, weeding, cultivation and blossom end rot.
Monitor the leaves, especially lower ones, for the first symptoms of tomato early blight and Septoria leaf spot. Remove infected leaves and begin application of a labeled fungicide. Tomato late blight can strike suddenly, often attacking the upper stems and foliage first, and then rapidly cause fruit infection. New, more aggressive fungus strains now exist, so early warning and prevention is critical. It is essential that homeowners monitor information from cooperative extension offices to know if late blight has been found in their region on either tomato or potato.
Remove all plant debris from the garden in the fall. Many tomato blight organisms overwinter on dried plant tissues.

Next Spring:

Inspect transplants and purchase healthy plants. Select wilt and nematode resistant varieties. Look for the capital letters V, F, and N following the cultivar name.
Choose a range of varieties that mature at different times. The earlier the tomato variety matures, the more susceptible it is to early blight.
Practice crop rotation by planting tomatoes and related vegetables in a different spot in the garden every year. Do not plant tomatoes and potatoes next to each other since they both are susceptible to early and late blight.
Allow adequate spacing between plants.

The American Phytopathological Society is a professional scientific organization dedicated to the study and control of plant disease with more than 5,000 members worldwide. For more information, visit APSnet.