Symptoms of early blight on a tomato leaf.
Wet weather is a major contributor to a variety of diseases and pests in gardens, lawns, and shrubs. Many fungal and bacterial pathogens thrive in warm and humid conditions. Those conditions are also ideal for a variety of insect pests.
Tomato diseases are some of most often reported issues through the Extension Office. Most are soilborne diseases that can persist for multiple years in gardens. They are often introduced from transplanted seedlings, infected seed, or in displaced soil. Once established, they are difficult to eradicate. These include: Verticillium wilt, Fusarium wilt, corky root Rot, black dot, root knot, Pythium rot, and Sclerotinia white mold.
Prevention is the best treatment. Do not plant unhealthy seedlings, maintain good fertility and watering, and sanitize equipment between working with unhealthy and healthy plants. Practice good sanitation methods by removing diseased plants and plant parts. Once you notice disease, rotate crops. Prevent problems in future years by rotating out of the tomato family (Solanaceae). This includes potatoes, eggplant, and peppers. Some ornamental plants, such as Petunia, are also susceptible.
Photos and additional management tips can be found online at: https://ohioline.osu.edu/factsheet/hyg-3314.
For general information about growing tomatoes and selecting varieties, consult this factsheet: https://ohioline.osu.edu/factsheet/HYG-1624.
– Christine Gelley, Agriculture and Natural Resources Educator, Noble County