Growing tomato plants is a fun summer project and a favorite pastime for many backyard gardeners. Although tomato plants are considered easy to raise and grow, there are some plant problems that when left untreated can wipe out a tomato crop and even affect future tomato plants if they are grown in the same area. Many of these tomato plant problems appear quite similar, but identifying these problems and knowing the correct treatment can help keep tomato plants healthy.
Bacterial canker (Corynebacterium michiganders) is considered one of the most difficult tomato diseases to detect because its symptoms are so varied. Symptoms may include 1/4-inch lesions on leaves or may appear as raised white spots that measure about 1/16-inch in diameter. White spots that have dark centers called "bird's eyes" can develop on the fruit and eventually these spots merge with other spots, giving the tomato a mottled look. As the disease progresses, leaves wilt and cankers may be seen on the stems. Since this disease is so hard to control, plants should be cut off at the ground and placed in plastic bags for removal as soon as bacterial canker is confirmed. After all debris is removed, seedbeds and soil must be sterilized to keep bacterial canker from returning.
Blossom End Rot
Blossom end rot (BER) is a common problem for tomato growers. It is caused by a lack of calcium and water. BER begins at the blossom end of the tomato and starts as a dark circle that becomes larger as the fruit grows. Since it is not a disease or infestation,
it cannot be controlled with fungicides or insecticides. Preventive measures can be taken, however, by applying lime around the garden area and keeping plants watered. If BER has already started, a chemical solution containing calcium chloride sprayed on the leaves may help, but soil should still be treated to provide the proper calcium amounts for tomato plants.
Late blight is a fungal disease caused by Phytophthora infestans. It typically occurs in the late summer after there has been a good deal of rain in an area. Symptoms include dark or dead areas on the plant's leaves, fruit and stems. As the disease progresses, vines start to appear dead and the tomatoes develop dark black spots as they start to rot. Late blight can be controlled with fungicide or a copper spray, but the best way to fight it is to catch it early and remove any leaves or plant parts that start to show symptoms. To keep late blight from returning, remove dead plants from the area and dispose of them away from the garden area.