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How to Prevent Common Tomato Plant Diseases

Healthy, disease free green tomatoes on vine.Whether you are a regular vegetable gardener or are new to growing tomatoes, your gardening joys can be interrupted by tomato plant disease. Your aim is to produce fresh healthy tomatoes, but they can suffer from all sorts of diseases and plant pests. If you want to enjoy your home-grown tomatoes, be prepared to experience tomato problems including tomato diseases, tomato plant pests, and learn how to deal with them.

What Causes Tomato Plant Diseases?

Weather conditions and climate are usually responsible for tomato plant problems. Fungus is another cause. However, tomato plant diseases are rarely fatal if proper management is exercised. You need to catch any tomato plant disease early before it spreads to other plants and possibly other family plants such as potatoes, eggplants and peppers. Following are some of the more common tomato plant diseases, their symptoms and how to care for your plants if disease threatens them.

Signs of Tomato Plant Disease and How to Treat Them

Fusarium and verticillim are known to be the two most harmful fungal diseases which attack tomato plants. Plants that are affected would display yellowing, and also wilting of their older leaves around midsummer making it hard to grow tomatoes. The yellowing continues to move up the stem until the entire plant is dead. To fight these tomato plant diseases, you need to practice crop rotation. Remove and destroy all debris present and do not replant where the disease occurred previously. Plant only wilt resistant tomato varieties such as those designated with VF-11 on the seed package or plant marker to prevent against verticillim. To protect against fusarium, choose resistant varieties denoted with the initial "F" on the seed package or plant marker.

Blossom End Rot and Related Tomato Plant Diseases

Another very common plant problem affecting tomatoes is that of blossom end rot. Your fruits may appear to be normal at the top, but when you pick them you observe a large, ugly black spot on the blossom end of the tomato. Blossom end rot is not a tomato plant disease; the spot is caused by a lack of calcium in the fruit. You can avoid this problem by watering and mulching your plants regularly. Water close to the soil and avoid water spray on the leaves. Keeping moisture even also helps to keep the fruit from splitting and cracking.

Catfacing on Tomatoes

Catfacing is also not a tomato plant disease. It occurs when the fruits are deformed and the blossom ends are scarred and distorted when growing tomatoes. This condition can be caused by cool weather during the plant’s pollination. Plant your tomatoes during warm weather and cover them with plastic to protect them from rain and dew. This will also help to keep temperatures consistent. It is recommended to wait until 6-8 weeks after the first frost, if frost occurs in your area, before planting tomato seeds in containers. Ensure that they receive enough light throughout the process, before putting them out about 2-3 weeks after.

Avoiding Tomato Plant Problems Caused by Sunscald

Tomato plant problems also interact with each other sometimes. Your plants may lose their leaves from a wilt disease. This can cause the fruits to be exposed to sunlight, and they may develop sunscald. A chain reaction can take place here where a secondary invasion takes place by other decay–causing organisms. Cover theae exposed fruits with straw or some other loose covering to help protect them from the sunlight which is causing damage.

Other Common Tomato Plant Diseases

Early Blight is another tomato plant disease which is caused by a fungus that survives the winter on old vines. It usually appears in the form of dark spots surrounded by concentric bull's-eye rings on the leaves. If fruits touch the ground, they can develop fruit rot from anthracnose, and early and late blight. To avoid these problems, you should, space, stake or cage your tomatoes in such a way that they never touch the soil. Also, always allow enough space between the tomatoes for air circulation, so the foliage could dry off rapidly. Failing these precautions, fruits may rot inside, starting at the stem. Seedlings may have dark, sunken-in spots around the soil line. Once again, you should clean up and throw away all debris after harvest, rotate the crops and plant resistant cultivars. Try to avoid crowding of plants and prune for air circulation when growing tomatoes.

Late Blight is the other tomato plant disease which produces dark spots on the leaves which turn brown and then papery. Late blight can cause the entire plant to collapse all at once. The smell is also quite awful. This tomato plant disease is caused by a fungus that is favored by wet weather. The spores can travel great distances to affect plants. Blight can also occur after a sudden drop in temperature. To combat this tomato plant disease, avoid over-crowding and try to enhance air circulation among the plants. This can be achieved by using the methods of staking, caging and also pruning. You should also try to keep the leaves dry to avoid Late blight; it is a disease that thrives on moisture.

Septoria Leaf Spot is caused by a fungus which begins as yellow dots, but quickly turn into brown zones surrounded by yellow halos. The cells in the center of the spots die and turn whitish. This tomato plant disease calls for removal of the infected leaves.

Tobacco Mosaic Virus is yet another type of disease that affects tomato plants. It occurs when the leaves of the tomato plant take on a mottled yellow appearance. This can lead to a stringy growth habit, particularly in cool weather. This virus can live on a plant for 50 years and although there isn't any known cure for it, there are ways to keep the disease under control. If you have a contaminated plant, the disease can easily be transferred to other plants if the virus gets on your hands and gardening tools. The main solution to controlling the spread of the virus to the rest of the crop is through sanitation. Be sure to soap and wash your hands on a regular basis as you transplant. When it comes to your tools it would also be wise to immerse them in boiling water for a short time before adding them to a potent detergent. Next, uproot the seedlings that are plagued by the disease and destroy them immediately. Even after you have done away with the contaminated plants, you wash your hands and sterilize your tools before working with the other plants. Finally, when purchasing your plants, choose varieties denoted with a "T" on the seed package or plant marker.

Solution to low tomato yields

You may have huge towering plants which only produce a few tomatoes for the entire season. If this happens, it may be that you are applying too much nitrogen fertilizer. It is best to apply a balanced fertilizer high in phosphorus (the second number in the formula). Using a large nitrogen number would cause more leaf growth then tomato fruit production. A good natural plant hormone that helps blossoms set fruit is also worth trying.