Early blight in tomatoes is a constant worry for growers. So if a tomato plant gets early blight, what fungicide should be sprayed and how should it be controlled? Early blight in tomatoes occurs in northeast China, north China, east China, southwest China and other regions; the most important feature is that whether the disease spots appear on fruit, leaves or the main stem, they all have obvious concentric rings, so it is also called ring spot disease. Fruit spots are mainly near the fruit stalk, stem spots are often at the branching points, and leaf spots occur on the leaf mesophyll. A few key points are summarized below, let's take a look.
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<p style="text-indent:2em;"><span style="color:#FF8C00">1. Symptoms of early blight</span></p>
<p style="text-indent:2em;">Tomato early blight mainly harms leaves, but can also harm seedlings, stems and fruit. When seedlings are infected, dark brown spots appear at the base of the stem, slightly sunken with concentric rings. When leaves of mature plants are damaged, it mostly develops from the lower leaves upward. It first appears as water-soaked dark green spots, which after expanding become round or irregular ring-patterned spots. The edges often have a light green or yellow halo, and the center shows concentric rings. When humid, black mold grows on the spots, and in severe cases the leaves fall off.</p>
<p style="text-indent:2em;"><span style="color:#FF8C00">2. Occurrence pattern of early blight</span></p>
<p style="text-indent:2em;">Tomato early blight is caused by infection by Alternaria solani. The pathogen can overwinter in soil or on seeds, spreads through wind and rain, and invades through stomata, lenticels, wounds or the epidermis, causing disease. The pathogen can infect repeatedly in the field, and the disease is severe during the peak fruiting period. When the temperature is 20 degrees, relative humidity is above 80 percent, or in rainy weather, the disease tends to become epidemic. Continuous cropping land, low-lying land, excessive watering or poorly ventilated plots suffer severe disease.</p>
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<p style="text-indent:2em;"><span style="color:#FF8C00">3. Control of early blight</span></p>
<p style="text-indent:2em;"><span style="color:#008080">1. Chemical control of early blight</span></p>
<p style="text-indent:2em;">In the early stage of disease, promptly remove diseased leaves, diseased fruit and severely diseased branches, and begin spraying fungicides. To prevent resistance and improve prevention, it is recommended to rotate, alternate or use mixed formulations, spraying once a week for three consecutive sprays. When the disease is severe, remove the central diseased plants and diseased leaves, and promptly adopt a control method combining Chinese and Western approaches.</p>
<p style="text-indent:2em;"><span style="color:#008080">2. Agricultural control of early blight</span></p>
<p style="text-indent:2em;">(1) Grow strong seedlings: adjust the temperature and humidity of the seedbed well, and separate the seedlings when they reach the two-leaf-one-heart stage, being careful to prevent the seedlings from becoming leggy. This can prevent disease during the seedling stage.</p>
<p style="text-indent:2em;">(2) Crop rotation: tomatoes should be grown in a three-year rotation with non-solanaceous crops. Strengthen management: adopt high-ridge cultivation, fertilize reasonably, and after transplanting and seedling recovery, close the rows promptly to promote the growth of new roots. In greenhouses, control temperature and humidity well, and strengthen ventilation management.</p>
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<p style="text-indent:2em;">The above is what the Tuliu.com editor has brought you about what fungicide to spray for tomato early blight. We hope it is helpful to farmers. If you have any questions, you can leave a comment below, and I will reply to everyone promptly. See you next time.</p>
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Early blight of tomatoes is a persistent headache for growers. So what fungicide should be applied when tomatoes get early blight, and how should it be prevented and controlled? Early blight of tomatoes occurs in Northeast China, North China, East China, Southwest China and other regions. The most important feature is that no matter whether the lesions appear on the fruit, leaves or main stem, they all have obvious concentric rings, so it is also called ring spot disease. Fruit lesions are mainly near the fruit stalk, stem lesions are often at the branching points, and leaf lesions occur on the mesophyll. Here are a few key points summarized below, let's take a look.
I. Symptoms of early blight
Tomato early blight mainly harms the leaves, and can also harm seedlings, stems and fruits. When seedlings are infected, dark brown lesions appear at the base of the stem, slightly sunken with concentric rings. When leaves of adult plants are damaged, it mostly develops from the lower leaves upward. It first appears as water-soaked dark green lesions, which after expanding become round or irregular ring-patterned spots. The edges mostly have a light green or yellow halo, and the center shows concentric rings. When humid, black mold grows on the lesions, and in severe cases the leaves fall off.
II. Occurrence pattern of early blight
Tomato early blight is caused by infection with Alternaria solani. The pathogen can overwinter in soil or on seeds, spread by wind and rain, and invade through stomata, lenticels, wounds or the epidermis, causing disease. The pathogen can carry out multiple infections in the field, and the disease is severe during the peak fruiting period. When the temperature is 20 degrees, relative humidity is above 80 percent, or in cloudy and rainy weather, the disease is prone to become epidemic. Continuous cropping land, low-lying land, excessive watering or poorly ventilated plots suffer severe disease.
III. Prevention and control of early blight
1. Chemical control of early blight
In the early stage of the disease, promptly remove diseased leaves, diseased fruits and severely diseased branches, and begin spraying fungicides. To prevent resistance and improve prevention, rotating, alternating or compound use is advocated, spraying once a week for three consecutive sprays. When the disease is severe, remove the central diseased plants and diseased leaves, and promptly adopt a control method combining Chinese and Western approaches.
2. Agricultural control of early blight
(1) Cultivate strong seedlings: adjust the temperature and humidity of the seedbed well, and transplant seedlings when they grow to two leaves and one heart, taking care to prevent the seedlings from becoming leggy. This can prevent disease during the seedling stage.
(2) Crop rotation: tomatoes should be grown in a three-year rotation with non-solanaceous crops. Strengthen management: adopt high-ridge cultivation, rational fertilization, and after transplanting and seedling recovery, promptly close the rows to promote the growth of new roots. In greenhouses, control temperature and humidity well and strengthen ventilation management.
The above is what Tuliu.com's editor brings you on what fungicide to apply for tomato early blight. I hope it is helpful to farmers. If you have any questions, you can comment below, and I will reply promptly. See you next time.