Controlling Disease on Tomato Plants

No vegetable garden is complete without a few tomatoes. Who can resist a large, juicy Better Boy or a handful of cherry tomatoes? Like any plant, the tomato is susceptible to various diseases. The smart gardener will be prepared to combat common problems, so as to insure a healthy harvest.

Common Problems with Tomatoes

There are certain diseases that affect tomato plants, and many are easily controlled. Sometimes, however, infected plants must be removed to protect the rest of the garden. Poor weather and soil conditions often determine which kinds of disease will attack tomatoes. Common problems to watch for include blossom end rot, early and late blight, and specific kinds of soil fungus.

Blossom End Rot

Blossom end rot is a most irritating problem, and is easy to detect. Fruits look normal on the top, but will have large, black spots on the blossom end. This is caused by a calcium deficiency in the plant. Blossom end rot can be combated by adequate soil preparation before planting. The soil pH should be maintained at 6.5; compost and bone meal can be added to the bed to supply calcium. Once the problem has already occurred, control is difficult. Calcium can be added in the form of Epsom salts, crushed egg shells, or powdered milk. It may be best to remove the infected fruits.

Fusarium and Verticillim Wilt

Fusarium wilt is caused by a fungus in the soil. Leaves begin to yellow at the bottom of the plant, and they eventually turn brown and wilt. Plants will die if the fungus is not controlled, and any plants that show symptoms must be removed and destroyed. No chemical control is available for this fungus, and care must be taken when replanting in infected soil. Try buying fusarium wilt- resistant plants, which will have an ‚”F” after the name of the plant on the seed packet.

Verticillim wilt is also caused by a fungus that originates in the soil. The fungus can live in the soil for many years, so crop rotation is a good idea. Symptoms include leaves that turn yellow and dry up. This disease is most common during cool weather. Affected plants should be removed.

Tomato Blight

Tomato blight is a common annoyance for avid tomato growers. Early blight affects the foliage, stems, and fruit of tomatoes. Symptoms include dark spots on leaves; infected leaves also die prematurely. Copper and sulfur sprays can keep this fungus from growing, but sometimes the plant will need to be removed if it is too far gone. This prevents further contamination in the garden. Late blight affects the leaves and fruit of tomatoes and spreads rapidly. Cool, wet weather is generally the cause of late blight. Symptoms include gray spots all over leaves and white mold. Use copper spray to control late blight.

Prevention is the Key

As with any garden diseases, prevention is key. Once these problems have developed, they are difficult to control. Tomato growers should prepare beds thoroughly before planting, spray tomato plants early with fungicide control, feed plants regularly, and try not to overwater or let plants dry out. Every home garden can boast of a bountiful tomato harvest if plants are well cared-for.