How to treat tomato leaf spot?

Tomato bacterial leaf spot, caused by weak plant growth, in the early stage of the disease, with quinoline copper, or thiobacium copper or copper hydroxide or copper ammonia or leaf conazole, streptomycin, or allicin, mesomycin, or chlorobromoisocyanuric acid spray control, every seven to ten days once, two to three times.

1.chlorothalonil, mancozeb, copper hydroxide or 2Difenoconazole, methyl tobuzine or 3Azoxystrobin spray control, once every seven to ten days, two to three times in a row, and once every four days in severe cases, combined with brassinolide or potassium dihydrogen phosphate to regulate.

The first consideration for the prevention and control of tomato gray leaf spot is to select disease-resistant varieties. At the same time, the following measures are applied:

First, agricultural prevention and control.

Crop rotation is practiced. rotation with non-Solanaceae crops such as cruciferous and cucurbitaceae; Strengthen field management. When planting, sufficient basal fertilizer was applied, and organic fertilizer, phosphorus and potassium fertilizer were added to enhance the host's disease resistance. If conditions permit, drip irrigation or dark irrigation under the membrane should be implemented as far as possible, and ventilation should be strengthened to reduce microclimate humidity; After harvesting, the diseased residues should be removed in time, burned in a centralized manner, and the soil should be turned deep in combination with land preparation to reduce the source of overwintering bacteria.

Second, chemical control.

At the beginning of the disease, spray 600 times of 75% chlorothalonil wettable powder, or 500 times of 40% closulfidan wettable powder, 400 500 times of 77% copper hydroxide wettable powder, 800 times of 80% mancozeb wettable powder, and 500 times of 50% thiophanate-methyl sulfur suspension, and control once every 10 days, and 2 3 times in a row.

Hello, the prevention and control methods are as follows:

1. Seeds of disease-resistant varieties are used.

2. The greenhouse protection area has just begun to spray in the early stage of the disease, and the special type for vegetable and fruit virus infection should be applied.

3. Eliminate the sick and disabled body immediately after the onset of the disease, and put an end to centralized damage. Use difenoconazole water-dispersed granules and spray once every 7-10 days.

4. Improve cultivation technology, apply phosphorus and potassium fertilizers to Haihai and Weihai to improve disease resistance.

[Symptoms and characteristics of tomato black spot disease]: Tomato black spot disease is also known as nail head spot disease and finger spot disease. It mainly damages fruits, leaves and stems.

The infected lesions of the fruit are grayish-brown or brown, round to oval and slightly concave, with distinct edges. There are one or several lesions on the fruit, which vary in size, and the spots have black mold, i.e., conidia and conidia.

Pathogenesis of tomato black spot disease]: Mycelium or conidia and conidia are overwintered in the soil with the diseased residues, and the conidia spread by airflow in the following spring, and the initial infection and re-infection are carried out. The bacterium is weakly parasitic and has a wide host range, and is usually attacked by this bacterium only when the plant grows weakly or the fruit has wounds.

Warm and humid weather is favorable for the development of the disease.

Tomato black spot control method]:

1) Strengthen water and fertilizer management, so that the plant grows steadily and steadily, which can reduce the damage.

2) Early spraying prevention, spraying 75 chlorothalonil wettable powder 600 times and 58 methalin-manganese zinc wettable powder 500 times from the green fruit stage. 50% dimethane wettable powder 500 times liquid, 80% mancozeb wettable powder 600 times liquid, 50% iprodimida wettable powder 1000 1500 times liquid, 40% grammetrian wettable powder 400 times liquid; Any one of the above agents is mixed with 50% chlorobromoisocyanuric acid soluble powder 1500 times, natural brassinin EC 6000-10000 times, green wind 95 600 times, and Kebao plant eugenics 1500-3000 times (transplanted crops, pesticide damage and fertilizer damage, frost damage, waterlogging damage, strong roots and seedlings, and 1500 times used for controlling prosperity).

Tomato black spot disease is a disease that occurs in tomatoes caused by Alternaria nail-headed tomatoes. Mainly damage the fruit, the fruit surface produces oval or round lesions, slightly concave, brown lesions, often black mold, and the later lesions are often combined with each other for large lesions. [3]

The plant is weakened or the fruit is wounded before it is attacked by the germ; Warm and humid weather is favorable for the occurrence of the disease. [4][6]

Control methods Agricultural control.

Variety selection: choose disease-free and disease-resistant varieties.

Clean the farm: remove the diseased and residual fruits in time after harvesting, take them out of the field to bury or burn, turn the soil deeply, and accelerate the decay and decomposition of the diseased residues. [1][2]

Strengthen cultivation management: deep ditch high furrow, reasonable dense planting, and often dredge the surrounding ditch system, prevent water accumulation after rain and reduce the groundwater level, in the pipe shed and multi-story greenhouse to protect the shed in the scientific fertilization, watering and fertilization to small water and less fertilizer watering frequently, increase the ventilation and humidity of the shed. In the early stage of the disease, the diseased fruit should be removed in time.

Chemical control. Seed disinfection: The introduction of commercial seeds before sowing dried seeds with fludioxonil suspension seed coating agent (when happy) coating, the coating dosage is 3-4, and the coating is dried and sown. [1][2]

Pesticide prevention and control: in the onset period, combined with the prevention and control of the main diseases of tomato, the selection of broad-spectrum fungicides for concurrent treatment, the prevention and control of tomato black spot disease in the appropriate period from the green fruit stage began to spray, the interval between drugs is 7-10 days, and the continuous prevention and control is 2-3 times.

Black spot disease, also known as head spot disease, mainly damages tomato fruits. Pay attention to prevention and control in planting, disinfect seeds before sowing, strengthen fertilizer and water management during growth, and appropriate top dressing to enhance plant disease resistance. If it enters the rainy season, you can spray the bacteriophilic cool suspension for prevention, and spray pesticides such as chlorothalonil wettable powder at the beginning of the disease**.

Strengthen field management to prevent injuries to tomato plants during agricultural operations; Scientifically regulate fertilizer and water to make the plant grow steadily; After harvesting, the fields should be cleaned in time, and the soil should be plowed and sunned.

March 22, 2018 Tomato black spot disease prevention measures 1, tomatoes should be covered with high furrows and mulch, and the density should be appropriate. 2. Strengthen water and fertilizer management, apply enough manure, and be timely.

You can buy Bordeaux liquid or carbendazim according to the proportion of water spraying, generally speaking, spraying for a week can see the effect, if it rains, you have to spray again.

Hello dear, glad to answer for you. Tomato leaf spot prevention and control, spraying with pesticides such as chlorothalonil, methyl tobuzin, slipming benethermetaconazole and so on. Tomato leaf spot is usually mixed with a solution of oxystrobin oxystrobin oxyconazole, mixed with an appropriate copper agent of Quincin, and then straightened.

In the pre-onset or initial stage of the disease, 65% zeb (blue label) wettable powder or 40% chlorothalonil (saiyan) suspension 500 times liquid spray is used for prevention. After that, I will use it again once a week. After the onset of the disease, 25% difenoconazole plus 25% propiconazole (Zhanliang) emulsifiable concentrate 1500 times, or 15% difenoconazole plus 15% propiconazole (Birun) emulsifiable concentrate 1000 times liquid spray**.

I hope my answer can help you.

Summary. One is the macula caused by tomato leaf mold. Leaf mold is prone to occur in the late stage of tomato planting in spring when the temperature in the greenhouse rises and then encounters high humidity.

Leaf mold germinates when there are water droplets on the foliage, which is why vegetable farmers get seriously ill after watering. When the humidity is greater than 80, it is conducive to the occurrence of the disease, which is a high temperature and high humidity disease. Leaf mold is mainly impregnated leaves, the leaves appear light yellow green spots at the beginning, and the back of the leaves has a white mold layer in high humidity.

As the disease progresses, the leaves will be reversed, twisted, and finally the leaves will dry up.

What is the disease of macular on tomato leaves and how to treat it.

One is the macula caused by tomato leaf mold. Leaf mold is prone to occur in the late stage of tomato planting in spring when the temperature in the greenhouse rises and then encounters high humidity. Leaf mold germinates when there are water droplets on the foliage, which is why vegetable farmers get seriously ill after watering.

When the humidity is greater than 80, it is conducive to the occurrence of the disease, which is a high temperature and high humidity disease. Leaf mold is mainly impregnated leaves, the leaves appear light yellow green spots at the beginning, and the leaves refer to the white mold layer on the back of the leaves in high humidity. As the disease does not develop, the leaves will be reversed, twisted, and finally the leaves will dry up.

Control method: improve the soil and avoid acidic or alkaline celery soil. Apply enough well-rotted organic fertilizer, and timely and appropriate amount of top dressing.

Formula fertilization is used to achieve a reasonable ratio of nitrogen, phosphorus and potassium fertilizers to avoid excessive nitrogen and potassium fertilizers. Apply a complete fertilizer containing magnesium, such as a fertilizer with a dry matter magnesium content. Properly control irrigation, avoid flood irrigation, and promote root growth and development.

Do a good job of heating and heat preservation in the early stage, and the ground temperature should be kept above 16. Magnesium fertilizer supplementation, after the initial dismantling of the disease, foliar spraying of magnesium sulfate solution, or spraying compound micro-fertilizer.

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After taking a look, the macular of tomato leaves is caused by tomato leaf mold, which can be smoked with sulfur or chlorothalonil fume, sprayed with Xun eggplant leaf mold dust agent, or sprayed with 1500 times of Amicida liquid or 1500 times of Shigao water dispersible pulling agent. 7 Once a day in 10 days, the temperature of the stool should be controlled below 25 and the humidity should be below 80 mu, which is not conducive to the occurrence of this disease.

Symptoms: Tomatoes have dark spots on their leaves, possibly infected with brown spot. Brown spot disease mainly harms the leaves, forming nearly round or oval lesions on the leaf surface, the edge of the lesion is obvious, the color is gray-brown, the lesion ** becomes thin and concave, shiny, and there is dark brown mold on the surface of the lesion when the air humidity is large.

Prevention and control: select disease-resistant varieties for cultivation, uproot diseased plants in time, and do a good job of pastoral cleaning. In the early stage of the disease, spray 500 times of 25% copper ammonia aqueous solution, 500 times of 50% mixed sulfur suspension, and 400-500 times of 77% copper hydroxide wettable powder, spray once every 7-10 days, and spray 2-3 times continuously.

Symptoms: Coal stain disease mainly affects the leaves, but also the fruits. In the early stage of the disease, there will be a tiled white mold pile on the surface and back of the leaves, and then gradually become gray-black to black-brown mold piles, with the development of the disease, the diseased leaves yellow, the back of the mold mesophyll tissue necrosis, in severe cases, will cause the leaves to be densely covered with lesions, and the leaves will die in a short period of time.

Prevention and control: remove the sick and disabled bodies in time, strengthen ventilation and ventilation, and drain water in time after rain. In the early stage of the disease, you can spray 400 times of 40% sterilized Dan wettable powder, 1500 times of 50% dogalin wettable powder, and 600 times of 40% carbendazim suspension, spray once every 15 days, and spray 2-3 times continuously.

In addition to spraying and curing diseases, it is also necessary to timely control aphids, whiteflies and scale insects and other transmission mediators, which can effectively prevent the occurrence of diseases.

Tomatoes are one of the common vegetables, but if they are not well managed and protected, they are susceptible to diseases that affect yield and quality. Among them, tomato black spot is a relatively common disease, which brings great trouble to the growth of tomato suspicion. So, what kind of medicine can we use against this disease?

First, we can use propiconazole. This drug acts on Streptomyces and can effectively inhibit the growth and reproduction of the bacteria and prevent the spread of the disease. When using, we need to choose the appropriate dosage and application method according to the specific situation and the degree of disease development of tomato black spot.

In addition, we can also use copper sulfate. This drug also has a significant inhibitory and bactericidal effect on melanoma. However, it should be noted that in the process of using copper sulfate for disease control, we must pay attention to the concentration and application method of the drug, so as to avoid drug overdose and pesticide damage, which will cause damage to crops.

In short, tomato black spot is a common disease, and the control measures need to be adapted to local conditions, and appropriate methods and drugs should be selected to treat it. In practice, we also need to pay attention to the dosage, time and method of administration of drugs to achieve better prevention and control effects.