Common problems with homegrown tomatoes
Tomatoes are the most popular vegetable in the garden. Ninety percent of my vegetable calls are problems with tomatoes. Here are a few of the diseases and problems affecting tomatoes:
The first is failure to set fruit. Every year gardeners have tomatoes that flower, but do not set fruit. They can be caused by abnormally hot weather, low soil moisture, excessive shading, or over-fertilizing. Be sure to mulch your tomatoes and keep them from environmental stresses.
Disease problems
Blossom-end rot: This disorder causes the fruit to have a dark sunken area on the blossom end. This can be prevented by adding a cup of Dolomitic lime mixed with soil to your tomato planting hole. Maintaining a good even soil moisture at all times by adding mulch can prevent blossom-end rot. Mulches are helpful for their ability to moderate soil moisture fluctuations as well as to eliminate the need for cultivation. A soil test in advance of planting may pinpoint a soil pH problem.
Mosaic diseases: There are several viruses that will produce mottling and curling of leaves and disfiguration of the fruit: These diseases are spread by insects, animals, and humans. Aphids are the chief insect vectors and should be controlled by using insecticides. Animals and humans can also carry this disease from one plant to another. Do not allow anyone to smoke in your garden. Smokers should always wash their hands before touching the plants. Tobacco mosaic virus (TMV) can be spread from many plants to tomatoes.
Wilts: Fusarium and Verticillium can cause early dying of tomatoes. These diseases cause the plant to wilt even with good moisture. If you cut the stem of the plant the vascular or conducting tissue will be discolored.
Both of these wilts are soil borne and widespread throughout the South. These wilts can infect potatoes, peppers, eggplant, melons, and many other vegetables and some ornamentals. The only solution is to use resistant varieties.
Leaf roll: This disorder is characterized by upward rolling of tomato leaflets on older leaves. Leaf roll has been associated with a specific gene (wilt gene). Symptoms are usually seen when plants have a heavy fruit load. Environmental factors that contribute to this disorder are high temperature, drought, and periods of wet soil conditions.
Blights and other fungus diseases
There are a number of fungi that are important on tomatoes. Most of these can be controlled by regular sprays of recommended fungicides (Daconil, ® Maneb, and ® Mancozeb). For early and late blights, anthracnose and fruit rots, use a fungicide once a week when the disease first appears.
Insects
Aphids: Aphids (plant lice) cause a loss of plant vigor and may carry disease. There are many non-chemical and chemical preparations for controlling aphids. Read and follow label directions carefully. Insecticidal soap is an organic spray that controls many soft bodied insects.
White Fly: White fly can be a major problem in tomatoes. Many times when you touch a plant there will be just a cloud of white. These white flies feed on the plant causing weak growth. One nonchemical control method is to place a yellow container (a gallon milk jug) covered with a sticky substance (syrup or glue) near your tomato plants. The white flies are attracted to the yellow color. They will fly onto the yellow object and become trapped there. The yellow trap must be the same height as the tomato plant.
Tomato Horn Worm: The tomato hornworm is a large green worm with a horn on the back end: Hand-pick these large insects from plants. Bacillus thuringiensis can be used as a biological control for Horn worms when they are small. We call this a b+ product.
Look for these diseases and insects on your tomatoes this summer. Remember tomatoes need to be harvested twice weekly as they ripen. Protect your healthy fruit by removing all rotten and damaged fruit.
Good luck with your tomatoes this season!