Teachers: What medicine is good for tomato blight

Ask how to treat tomato late blight and what medicine should be given.

1. Symptoms: The leaves, stems and fruits of tomato late blight will be damaged to varying degrees, and the leaves and green fruits at the adult stage are particularly seriously damaged. When the leaves are diseased, they will start to appear from the tip or edge of the leaf, and in the morning, white mold will grow on the diseased spots on the back of the leaf; If the stem is diseased, there will also be black and yellow lesions, and the diseased part will be concave inward, and the stem will generally break from this; When the fruit is diseased, when the fruit is not ripe and green, black and yellow spots will appear, and the lesions will start to be harder and will slowly rot.

2. Causes of the disease: 1. The cleaning of field residues is not timely and thorough, resulting in the accumulation of pathogens in the field. 2. The interval between crop rotation years is short, and the adjacent planting of tomatoes and potatoes causes cross-infection.

This is the cause of tomato late blight**. 3. When cultivating, the tomato planting density is large, and the shade and ventilation in the field are poor, especially when the weather is cloudy and rainy, the rainfall is large, the humidity is high, and the temperature is low, the onset of the disease is early and the disease is serious.

4. Unreasonable fertilization, especially in the growing season, if the protective agent is not sprayed in advance, it creates favorable natural conditions for the onset of the disease. 3. Prevention and control methods: 1. The selection of varieties should be adapted to local conditions, and disease-resistant varieties should be selected, especially in humid areas or rainy years.

2. After selecting the seeds, it should be strictly disinfected, and it can be sprayed with 500 times of 70% mancozeb wettable powder, and then soaked in 55 water for 30min, and then germinated after draining. 3. Crop rotation with non-solanaceae crops for 2-3 years.

Before planting, carefully inspect and remove the diseased plants, and spray the medicine once. 4. The better agents are manganese zinc, cyanogluzole, frost urea, di-noyloylamine, enoylmorpholine, flumorpholine, pyraclostrobin, etc., when the condition is serious, the above two agents can be mixed with the same amount of spray. When it is heavier, you can use any of the above agents to mix 35 ml of copper noble, or you can mix 35 grams of Dakoning, and the effect is good.

The general prevention and control requires at least two times, with an interval of 5-7 days. Pay attention to reasonable dense planting, the density of planting infinite growth type can be smaller, and the density of limited growth type should be larger. All.

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Prevention program: R. solanacearum 30-50ml Wofengsu 25ml garlic oil 15ml mixed with water 30 kg sprayed regularly. Remarks: Garlic oil should be halved at the seedling stage, 5-7ml.

Fourth, ** program 70-100ml garlic oil 15ml wofengsu 25ml organic silicon mixed with water 30 kg spray 2-3 times, spray 1 time in 3 days, change to prevention after control. Remarks: Garlic oil should be halved at the seedling stage, 5-7ml.

Tomato late blight pesticide control.

Before the diseased plants in the center of the field do not exceed 1%, the following pesticides should be sprayed immediately: 40% ethylphosphine aluminum wettable powder 200 times, 50% chlorothalonil wettable powder 400 times, 25% Ruifuxyl wettable powder 800 times, 50% promethane wettable powder 1000 times, 64% alum wettable powder 500 times, Pulik water solution 800 times. Every 667 square meters of protected land cultivation can be fumigated with 250 grams of 45% chlorothalonil fume, or sprayed with 5% chlorothalonil compound dust agent (1000 grams per 667 square meters).

The above agents are sprayed once every 7 days, and sprayed 3 or 4 times in a row according to the condition.

Data Extension: Prevention and Control Methods.

1) Rotation.

Crop rotation with non-solanaceae crops for more than 3 years.

2) Removal of diseased residues.

During the onset season, the diseased leaves and fruits should be removed in time and buried deeply, and the diseased residues should be removed in time after harvesting.

3) Strengthen field management.

Watering should be carried out on a sunny day to prevent flooding. After irrigation in the protected area, it should be timely ventilated and drained, reasonably densely planted, pruned in time, removed the old leaves of the lower part of the plant, improved the ventilation and light transmission conditions, and increased the air volume under the premise of ensuring humidity.

Symptoms: Seedlings, leaves, fruits and stems can be damaged, with leaves and green fruits being the most severely damaged at the adult stage. At the seedling stage, the leaves appear dark green water-stained lesions, and gradually develop to the main stem, causing the petiole and the main stem to appear black-brown and rot, when the humidity is high, the diseased part produces a sparse white mold layer, and the young stem base forms water-stained shrinkage, the seedlings wilt and lodging, and the leaf damage mostly starts from the leaf tip and leaf edge of the lower leaf of the plant, and the initial stage is dark green water-stained lesions, the edge is not neat, and it turns brown after expansion, and the disease spots on the stem are black-brown and rotten, which can cause the plant to wilt.

The lesions are oily, dark green at first, and gradually turn dark brown to tan, slightly concave, and the edges are moire.

Symptoms and hazards of tomato late blight.

Tomato late blight is a major disease of tomatoes. It occurs in all averages. The disease is highly endemic and destructive, often causing a 20% to 30% reduction in production.

Late blight can damage tomato leaves, stems and fruits, but it is seriously affected by leaves and green fruits.

1. Symptoms of tomato leaf damage: Generally, the disease starts from the tip or edge of the lower leaf of the plant, and then gradually spreads to the upper leaves and fruits. At first, it is a dark green water-soaked nonplastic lesion, with no obvious boundary at the junction between disease and health, and turns brown after enlargement.

When the air is humid, the lesions will expand rapidly, and a layer of white mold can be seen on the edges of the lesions on the back of the leaves. When the air is dry, the lesions are greenish-brown, then darken brown and gradually dry up.

2. Symptoms of tomato stem damage: the lesions turn from water-stained to dark brown to black-brown, slightly concave downward, the diseased stem tissue becomes soft, the plant wilts, and the severely diseased part is broken and the stems and leaves die.

3. Symptoms of tomato fruit damage: generally start from the fruit surface near the fruit stalk of the green fruit before coloring, and the lesions are not obvious oil-soaked large spots, which gradually develop to the surroundings, and gradually become dark brown in the later stage, the lesions are slightly concave, the diseased fruit is hard and not soft rot, the edges are not red, and a layer of white mold is produced on the surface of the lesions when it is wet. During the storage, transportation and sale of the fruit, it can continue to be damaged, and in severe cases, it can lead to a large amount of damage to the tomato.

How to prevent and control tomato late blight, and what are the specific drugs for tomato late blight?

2. Transmission route and causes of tomato late blight.

1. Tomato late blight mainly overwinters in the soil with the diseased residues, and can also overwinter in tomato and potato tubers cultivated in winter. When conditions are suitable, it spreads to the tomato plant by air currents or rainwater, forming a central diseased plant in the field. The hyphae of the pathogen expand and spread between host cells or within cells, and after 3 to 4 days of incubation, the disease grows hyphae and sporangia, and spreads through wind and rain for multiple infections.

Direct invasion from the stomata or epidermis. The hyphal development is suitable for 24 temperatures, up to 30.

2. Late blight grows in tomatoes.

The so-called proficiency, you can imagine that we do the first grade of primary school calculation problems, each of which is actually very simple for us. But when we complete 1000 questions in a timed situation, it is not necessarily all right.

Tomato late blight, the resistance is different in different places, it is recommended to choose one or two mixtures of enoylmorpholine, manganese-zinc frost urea, downy mildew hydrochloride, methamaline manganese-zinc, oxazole, fluridine, oxazole, flumorpholine manganese-zinc, cyanofrostazole, fluether amide and other ingredients to choose one or two mixtures (in severe cases), alternately.

If it is a protected greenhouse, pay attention to controlling the humidity, and on rainy days, it is recommended to use chlorothalonil fogging agent to control the condition. If the vine is in serious condition, you can use one of the above products and a little water to apply the diseased part at the same time.

Prevention first, comprehensive prevention and control (reduce the amount of disease prevention). Use pesticide ingredients alternately, and do not use the same pesticide ingredients consecutively. This is the principle of crop protection.

Tomato early blight, also known as "ring disease", is one of the important diseases that harm tomatoes. For a long time, some areas have been promoting tomato varieties that are resistant to viral diseases but not early blight, resulting in serious occurrence of early blight. This pathogen has a wide range of hosts, and in addition to tomatoes, it can also harm eggplant, pepper and other solanaceous vegetable crops and potatoes.

Tomato early blight control technology.

1. Selection of varieties.

Choose disease-resistant varieties, such as Dilia, Caudali, Kaixuan 158 and other varieties are more disease-resistant, and can be used in severely ill areas. In general, the disease of early-maturing varieties and narrow-leaved varieties is mild, and the incidence of high-tree, large-seedling, and large-leaved varieties is serious.

2. Pay attention to crop rotation.

Given that pathogens can survive for more than one year, it is necessary to pay attention to crop rotation. Generally, it is rotated with non-solanaceae crops for more than two years. When choosing a seedbed, it is also necessary to pay enough attention.

3. Treatment of seeds.

On the basis of paying attention to the selection of seeds from disease-free plots and disease-free plants, in addition to the prevention of other diseases after harvest, the seeds after harvest are treated with 70 dry heat treatment for 72 hours (note that the seeds are given a certain post-maturity transformation period after harvest), and 52 warm water and natural cooling treatment can be used for 30 minutes before sowing, and then cold water is soaked in seed germination.

Symptoms: In the early stage of leaf disease, the lesions are small dark green water-stained spots, which are round or nearly circular after enlargement, slightly concave, dark brown on the edges, and have obvious concentric ring patterns. When wet, black mold appears on the lesions, and the diseased leaves often turn yellow and fall off or dry up to death.

When the stem is damaged, it is a grayish-brown depressed long lesion, which can cause the stem to fold. When the fruit is damaged, a round or oval lesion is formed near the sepal at first, and it is pitted, and the fruit cracks and turns red early in the later stage.

Tomato early blight leaves and stems.

Control method: Treat the seeds, treat the seeds with pesticides. Reasonable crop rotation, 3 to 4 years of crop rotation with Solanaceae crops.

Strengthen management. Use small water irrigation to reduce the humidity in the shed as much as possible to inhibit the spread of diseases; Increase the application of phosphorus and potassium fertilizers to improve the disease resistance of plants. Pharmaceutical prevention and control.

At the beginning of the disease, spray 500 times of 65% mancozeb wettable powder, or 800 times of carbendazim wettable powder, or 800 times of 50% methaloxin wettable powder. It can also use 45% chlorothalonil aerosol agent, 3750 grams per hectare, ignite the smoke agent from the inside to the outside one by one, and close the greenhouse or greenhouse for 2 3 hours, with significant results.

In addition to the selection of disease-resistant varieties and the implementation of seed disinfection, the prevention and control of tomato early blight mainly takes the following measures:

First, agricultural prevention and control.

Crop rotation is practiced. Crop rotation with non-Solanaceae plants for more than 2 years. Strengthen cultivation management.

Carry out seed disinfection and colonize disease-free and strong seedlings; control the planting density, and pay attention to proper pruning and leaf thinning to facilitate ventilation and light transmission; Remove the bottom leaves, diseased leaves, and diseased fruits in time, and take them out of the field to bury or burn them. Second, ecological prevention and control.

After pulling seedlings, remove the disease and residues in the field in time, and disinfect the shed in the protected area, and you can choose to use 45% chlorothalonil smoke removal agent 2250 grams per 667 meters for fumigation and disinfection; In early spring, the temperature difference between day and night is large, which is conducive to the occurrence and spread of the disease, and the temperature and humidity in the shed should be adjusted, especially in the early stage of planting, the time of stuffy shed should not be too long, to prevent the humidity in the shed from being too large and the temperature is too high, the temperature should be controlled at 20 25 during the day and 12 15 at night, and the relative humidity of the air should be controlled below 80%, and the form of drip irrigation or dark irrigation under the film can be used if conditions permit. Third, pharmaceutical prevention and control.

The spraying period is very important, and generally the first diseased plants in the field should be sprayed immediately or even before the onset of the disease. The optional agents are 50% iprodione wettable powder 1000 1500 times liquid, 80% mancozeb wettable powder 600 times liquid, 50% Fu-heterobacterial wettable powder 800 times liquid, 70% mancozeb 500 times liquid, and 45% chlorothalonil smoke agent can also be used in protected areas to use 250 grams per 667 meters2. In addition, the dust method can also be used for prevention and control, spraying 5% chlorothalonil dust agent 1 kg per 667 m2 each time at the beginning of the disease, once every 9 days, and continuous prevention and control 3 4 times.

The prevention and control of early blight is often less effective after the onset of the disease.

Prevention and control methods: Raising temperature and reducing humidity are the key to disease prevention. That is, the early spring cultivation in the shed adopts high furrow mulch, small watering, and more cultivation to loosen the soil to increase the ground temperature.

Control watering during the flowering period of eggplant and eggplant, increase ventilation, and reduce condensation. After fertilization, remove the petals of eggplant and eggplant as soon as possible to prevent pathogens from infecting the flowers. Spray 50% iprodione wettable powder 1500 times, 50% Nonlilin wettable powder 1000 times, 50% Suclin 500 times and 50% carbendazim wettable powder 600 times at the flowering stage.

It can also be smoked with 10% sclerotinia sclerotinia (Suclin) smoke before and after flowering, 400 grams per mu. When the flowering of eggplant is carried out, 50% Nongli wettable powder, or 50% iprodione, or 50% carbendazim are added to the prepared 2,4-d or anti-drop diluent dilution, and the flowers are dipped in flowers, which has good anti-flowering and disease prevention effects.

Tomato early blight, the leaves are damaged at the adult stage, mostly from the lower leaves of the plant upwards, the initial water-soaked dark green lesions, after the expansion of the round or irregular ring spots, the edges have more light green or yellow halos, the middle part is concentric rings, the black mold layer grows on the lesions when wet, and the leaves fall off when severe. It can be used with flusilazole, benzo. Azoxystrobin, iprodione, bromonitrile, pyraclostrobin and other foliar fertilizer sprays were sprayed continuously every 7 days.

Tomato late blight, the cause of the disease, cloudy and rainy, heavy rainfall, high humidity, low temperature, early onset and serious disease. Generally occurs in leaves, stems, fruits and leaves, most of the lesions start from the tip of the leaf or the leaf margin, at first it is a water-soaked green spot, and then gradually expand, when the air humidity is high, the lesion expands rapidly, can spread to most of the leaf or even the whole leaf, and can invade the petiole and stem along the leaf vein, forming brown stripes. The cortex of the stem forms brown streaks of different lengths, and the lesions also grow sparse white frosty mold in humid environments.

Can be used with Frosturea · Manganese-zinc, downy mildew, ethylphosphine aluminum · Manganese-zinc, methae, manganese-zinc, enoylmorpholine, downy mildew · Plague net, silver farry (flumichlor. Dimycocarb), Pulik (downy mildew hydrochloride) and other foliar fertilizer spray control, continuous spraying once every 7 days.