Tomatoes are a delicious and versatile fruit, but they're also prone to some common tomato diseases. Some of these can be devastating to your tomatoes, while others are just unsightly and annoying. This article will go over some of the most common tomato diseases so you can take preventative action.
Alternaria blight is a fungal disease caused by Alternaria solani, a fungus that causes yellow spots on leaves and brown spots on fruit. It's most common in the Northeast, Midwest, and Pacific Northwest but can occur in all regions of the United States. Wind and rain spread Alternaria spores from plant to plant, so you'll want to make sure you're using resistant varieties of tomatoes if you're growing them in one of these areas. If your crop does get affected by this disease, quickly remove infected plants before they spread it further. Fungicide will also help prevent or treat the problem if caught early enough
Bacterial Speck is a common disease that affects your plants. The symptoms of this infection are yellow spots on leaves, which may spread to the stems and fruit. If you see these symptoms, you should take action to prevent them from getting worse by removing infected leaves and stems as well as keeping your plants healthy overall.
If you are using overhead watering methods, make sure that the water does not splash onto surrounding plants or soil; this can help reduce the risk for spreading diseases such as Bacterial Speck. Also keep in mind that if your tomato plants have had too much rain recently, it could cause fungal diseases like late blight to develop because damp conditions will encourage mold growth on tomatoes' surfaces (and other plants)
Often confused with Fusarium wilt, bacterial wilt is caused by the bacteria Ralstonia solanacearum. Although this disease may occur in any part of a plant, it typically affects the roots, causing them to rot and eventually killing the plant.
Bacterial wilt can be prevented by planting tomatoes in well-drained soil and avoiding overhead watering. If you already have an infected tomato plant, you can treat it by cutting away all affected parts of the plant at least 6 inches below any sign of wilting on stems or leaves. You should also remove any weeds near your tomato patch because they could harbor Ralstonia solanacearum bacteria that could infect your other plants as well.
Blossom End Rot
Blossom end rot first appears as a black or brown spot on the blossom end of the fruit. It's caused by a calcium deficiency that results in water-soaked areas at the blossom end of tomatoes.
Blossom end rot is most common during warm and humid weather, when plants need lots of water for growing fruits and vegetables.
The best way to prevent blossom-end rot is to ensure your tomato plant gets plenty of water, especially during times when it's especially hot outside or you've planted your tomato seedlings too late in the season (after May). Water deeply but infrequently so that soil remains slightly damp, never soggy. Ideally, you should water once every seven days or so—this will help prevent plants from getting stressed because they don't have enough nutrients available within their root systems yet!
If your tomatoes are already showing signs of having this problem, applying fertilizer containing calcium can help alleviate some symptoms but won't actually cure them completely since there's no real cure for blossom-end rot itself (although one could argue there isn't much difference between treating it vs curing it).
Curly Top Virus
Curly Top Virus is a common tomato disease. It's caused by a virus that attacks the plants and causes yellowing, stunting, and deformation of leaves and stems. The most noticeable symptom is curled leaves at the plant tips. Other symptoms include reduced fruit set and poor color development of fruits that are produced.
Curly Top Virus is spread by aphids (tiny insects), so if you see them on your plants or other nearby plants it's a good idea to apply an insecticide treatment to control them before they spread the disease further! You can also prevent this disease from spreading by cleaning up all infected areas whenever possible. If you find any signs of Curly Top Virus on your tomatoes remove any affected parts immediately so that nothing else in your garden gets infected!
Gray Leaf Spot
Gray leaf spot is a disease caused by the fungus Cercospora, which can be spread through the movement of infected leaves and plant debris. Symptoms of gray leaf spot include small, gray spots on leaves. As this disease progresses it turns into brown spots that are surrounded by yellow halos. The spots grow until they cover most of the infected leaf surface, resulting in leaf curl and premature defoliation.
The fungus survives in the soil for years and moves from plant to plant via wind-blown spores or splashing water from rain or overhead irrigation systems. The disease spreads rapidly when humidity levels are high and temperatures are between 70°F and 80°F (21°C-27°C).
Control: You can prevent gray leaf spot by rotating crops every three years so there aren’t any susceptible plants growing together at once; this will limit your exposure to inoculum (the material to which an organism like bacteria or virus attaches)
Septoria Leaf Spot
Septoria leaf spot is a fungal disease that causes spots on the leaves of tomatoes and other plants in the family Solanaceae. The fungus spreads by splashing water and insects. Septoria leaf spot is a common tomato disease, especially in warm, humid weather.
Southern blight is a serious disease that can wipe out your tomato plants. The fungus that causes it lives in the soil, so make sure to rotate your crops and clean up decaying leaves around the garden.
The best way to prevent this disease is by planting resistant varieties of tomatoes like 'Better Boy', 'Big Beef', and 'Brandywine'. If you do get Southern blight, treat it with copper sulfate or Bordeaux mixture (made from copper sulfate mixed with lime).
Target spot is a fungal disease that affects tomatoes. This disease can be identified by the small, circular spots on the leaves of the plant. Target spot is caused by the fungus Alternaria blight and is most prevalent in hot, humid weather.
To prevent this disease, keep your greenhouse humid but not wet and remove any weeds around your tomato plants to reduce competition for resources with your tomatoes.
Take care of your plants, it's worth it!
Watering: Watering is extremely important during the growth stages of tomatoes. Make sure that you water thoroughly but not too much (i.e., don't drown them). If you can sense that your plants are thirsty, then let them drink up as much as they need and then some more. You don't want to get into a situation where you've watered so much that there are puddles around the base of the plant because this may cause root rot or other fungal diseases to develop later on down the road.
Fertilizing: If you're planning to grow tomatoes for sale at farmers market stands or in-store sales at grocery stores, then make sure to fertilize regularly with a good organic fertilizer so that they have plenty of nutrients available throughout their life cycle and will produce more fruit per plant than if they were left unfertilized.
Pest Control: Keep an eye out for pests such as aphids (greenfly), spider mites and stinkbugs which love eating away at tomato leaves all day long until there's nothing left but bare stems and eventually those will collapse under their own weight without any leaves below them holding them upright anymore!
If you follow these tips, you can keep your tomato plants healthy and happy! And if they become diseased, don’t give up. Just try to figure out what might be going on and treat it accordingly. You should also treat any diseases that could spread to other plants in your garden or neighborhood.