How to Cure Diseased Tomato Plants

Tomatoes are one of the most popular vegetables to grow in the home garden. Unfortunately, they can be subject to numerous bacterial diseases and viruses that negatively impact fruit production.

Some tomato diseases, such as wilts and viruses, cannot be cured. Instead, good practices such as clearing away and destroying diseased tomatoes and plants; controlling non-beneficial insects; using mulches on bare soil; and consistent crop rotation can help eradicate these diseases and others.

Saving your tomatoes from problems involves early diagnosis and quick, sometimes persistent, treatment.

Things You'll Need

• Calcium chloride spray
• Copper fungicide
• Carbendazim spray
• Fertilizers high in potash and phosphate

Instructions

Blossom End Rot

1. Remove tomatoes that develop a sunken patch at the blossom end.

2. Spray affected plants with a gardening product containing calcium chloride.

3. Keep soil moist to help the plant increase its uptake of calcium as recommended in The Royal Horticultural Society's "Pests and Diseases."

Early and Late Tomato Blight

1. Water only at the base of the plant; do not water fruit or leaves as the spores that cause blights are spread by water and wind.

2. Water in the morning to give foliage time to dry during the day, limiting blight spore's ability to infect the plant.

3. Mulch soil around the plant's base to keep spores in the soil from spattering onto the plant during rains.

4. Remove all diseased tomato shoots and leaves, and any plants that are severely diseased.

5. Use copper-based fungicides to treat early signs of blight and as a preventative measure.

Grey Mold, Ghost Spot and Tomato Leaf Mold

1. Spray infected plants with carbendazim and improve air circulation by venting greenhouses or pruning tomato plants in gardens to create space between plants.

2. Remove dead and injured tomato plant parts before they can become infected.

3. Remove infected areas promptly, cutting back into healthy growth.

4. Mulch soil around the plant's base to keep spores in the soil from spattering onto the plant during rains.

Tomato Greenback and Blotchy Ripening

1. Feed plants with potash and phosphate as recommended in "Pests and Diseases."

2. Provide shading for plants situated in hot, bright sunlight, which can cause heat injury.

3. Ensure adequate air circulation around plants and keep well-watered.

Tips & Warnings

• Plant tomato varieties that resist diseases prevalent in your region. Check with your Cooperative Extension Agent for disease information.

• Clean gardening tools after use to ensure that diseases present in the soil are not spread among crops.

• Do not add diseased plant material to the compost heap or dig it into your soil as a green manure. Diseases can survive composting and decomposition, infecting the following year's crops. Instead, burn these materials or take them to a landfill or garbage dump.

References

• The Royal Horticultural Society's Pests and Disease; Pippa Greenwood and Andrew Halstead; 2003.
• Information on Tomato Blight from British Columbia's Ministry of Agriculture and Food
• Find Your Nearest Cooperative Extension Office at the USDA's Web site

Resources

• Information on Tomato Diseases and Disorders from the Iowa State University Extension