What medicine can be used to treat corn brown spot disease.

Corn brown spot occurs in most maize producing areas in China. It occurs more often in warm and humid areas, and in some years it is suddenly popular in maize fields.

1) Symptoms occur on leaves, leaf sheaths and stems, with the most lesions at the junction of leaves and leaf sheaths, often densely rowed, small spots at first, white to yellow, gradually turning into round, oval to linear spots, brown or purple-brown, and the surface of the lesions is cracked in the later stage, scattering brown powder. The diseased leaves are partially fragmented, the veins and vascular bundles remain like filaments, and the stems mostly occur near the nodes. (2) Infection route and pathogenesis of pathogenic bacteria: dormant sporangia overwinter in soil or on diseased residues.

In the middle and late growth period (July and August), when the temperature is high (23 30) and the humidity is high (relative humidity is more than 85%), the disease is easy to occur and epidemic. The disease is more severe in low-lying damp and continuous cropping plots. (3) Prevention and control methods: timely removal of diseased and residual plants in the field to reduce pathogen infection**; Reasonable drainage and irrigation to reduce field humidity; Do not use diseased plants as feed or fertilizer; Severely diseased fields should be rotated with other crops for 2 to 3 years.

Corn brown spot can be controlled with agents such as fenrustine or tebuconazole, which has a good effect.

When there are 4-5 leaves of corn, if the planted varieties are not resistant to disease, they are susceptible varieties, and the temperature is high at this time, the rainfall is large, the field humidity is large, and the light time is short, which is suitable for the occurrence of diseases and should be prevented as soon as possible.

Foliar spraying can be carried out with fungicides such as 1000-1500 times of 25 powder rust rather wettable powder, or 50-600 times of 50 carbendazim wettable powder, or 500-600 times of 70 methyl tobuzin wettable powder, which can have a better preventive effect. In the early stage of corn brown spot disease, foliar spraying with the above agents in time has a good control effect.

At the same time, an appropriate amount of potassium dihydrogen phosphate, urea, double-effect vitrin or other foliar fertilizers can be added when spraying pesticides to supplement corn nutrition, promote the healthy growth of corn, and improve disease resistance, thereby improving the control effect.

When spraying the agent, it can be sprayed 2-3 times in a row, with an interval of about 7 days. If it rains within 6 hours after spraying, it should be re-sprayed. With benzolat and oxychlorethoxal, it has a good control effect, and can be used with a kilogram of foliar spray on 750 kg of water.

Morphological characteristics of corn brown spot:

The pathogen is Chytridium cornis, which is single-celled, has a cell wall, and is multinucleated. Arthritridium can parasitize outside the host or in vivo. The ectoparasitic stage is short, and the thallus is outside the host body, producing thin and short pseudoroots that extend into the host cell.

After the thallus expands, it transforms into a long oval or oval parenchyma or gametocyst, releasing zoospores or gametocysts with a smaller body size.

The homotypic swimming gametes combine in pairs to form a zygote, and after germination, the zygote invades the host and develops into an amorphous thallus in the host and enters the endoparasitic stage. The cells are connected by filamentous pseudoroots, and the cells are enlarged and transformed into spherical dormant sporangia, which release larger zoospores from the opening of the capsule.

The above content reference: Encyclopedia - corn brown spot disease.

Corn brown spot can be prevented and controlled by powdery rust, carbendazim and chlorothalonil solution, when using the agent, it needs to be mixed evenly with water according to the dosage on the package, sprayed on the corn stalk, or watered in the soil, to avoid the growth of bacteria in the environment where the plant grows, so that it can grow healthily.

1. Pink rust

Corn brown spot disease can be controlled with powdery rust pesticides. That is, after the corn grows four to five true leaves, spray the powder rust or tebuconazole agent on the leaves of the plant to avoid brown spot disease on the plant.

2. Carbendazim

Corn brown spot can also be treated with carbendazim. That is, in the early stage of corn disease, buy carbendazim wettable powder from the market, and then pour it into the watering can according to the dosage on the package, pour water into the watering can, shake it evenly, and spray it on the corn-affected parts.

3. Chlorothalonil

Corn brown spot disease can also be prevented and controlled with chlorothalonil. First of all, you need to mix chlorothalonil with water, and then water it directly on the corn roots to eliminate the bacteria in the soil.

4. Later maintenance

In the process of later maintenance, it can provide river water or natural water rich in minerals for corn to keep the soil in a moist state, and can also provide rotted farmhouse fertilizer for corn to improve the growth rate of plants.

The prevention and control methods of corn brown spot include agricultural control and pesticide control.

In agricultural control, breeding and planting disease-resistant varieties are the most economical and effective control methods. The planting of disease-resistant varieties can not only protect the corn of the current year from harm, but also effectively reduce the source of infection. At present, the varieties with good disease resistance include Liyu 37 and Luoyu 336.

Before the onset or at the beginning of the disease, spray with 3000 times of 20% powdery rusting emulsifiable concentrate, 500 800 times of 50% carbendazim wettable powder, 800 1000 times of 70% methyl tobuzine wettable powder, 1000 times of Heguoli wettable powder or 1500 times of 25% dichloride demulsifiable concentrate, spray 1 time every 7 10 days, spray 2 3 times.

After the brown spot disease of corn, it can be sprayed on the part of the disease to eliminate the bacteria on the plant, for the corn plants with more serious diseases, it can be directly dug out of the soil and burned, and the quicklime is sprinkled on the excavated area for sterilization, and in the later stage of maintenance, the corn needs to be ventilated and ventilated to avoid bacterial breeding.

1. Spray the agent

When brown spot disease occurs in corn, the plant can be sprayed with a fungicide. First of all, you need to buy carbendazim wettable powder or chlorothalonil wettable powder from the market, and then according to the dosage on the package, mix the agent and water thoroughly, and spray it on the affected part of the corn to restore healthy growth.

2. Eliminate diseased strains

If the maize disease is severe, the brown spot plants need to be dug out of the soil and burned to avoid infecting other healthy plants, and the excavated area needs to be sprinkled with quicklime or sprayed with carbendazim solution to destroy the bacteria in the soil.

3. Ventilation

Brown spot disease in corn may be caused by poor ventilation between plants, so when maintaining corn, it can be regularly ventilated, the corn can be pruned, cut off its overgrown branches and leaves, and the corn can also be planted in a well-ventilated environment to maintain air circulation in the environment.

4. Prevention methods

Before planting corn, measures can be taken to prevent the appearance of brown spot disease, first of all, you need to choose excellent seeds with strong disease resistance for planting, and the seeds can also be soaked in potassium permanganate solution for disinfection before planting, after planting, you can provide corn with a balanced mixture of nitrogen, phosphorus and potassium, urea, and improve the immunity of the plant. How to treat corn brown spot.

<> corn brown spot is a disease caused by fungi that has a great impact on corn yield and quality. This article introduces the symptoms, pathogenesis and prevention and control measures of corn brown spot in detail for your reference.

The maize brown spot fungus infects leaves, leaf sheaths and stems, and the lesions at the junction between leaves and leaf sheaths are the most numerous, and they are often densely arranged.

The lesions are round or oval, brown to reddish-brown, and the small spots sometimes merge into large spots, and the leaf tissue near the lesions is often pink.

In the later stages of the disease, the epidermis of the lesion is broken, and a brown powder is emitted, and the leaf veins and vascular bundles remain filamentous. Lesions on stems mostly occur near the nodes and are easy to fold when windy.

Corn brown spot disease is a fungal disease, and its pathogen is Maize thrix, which belongs to the subphylum Flagellates. The pathogen overwinters in the soil or diseased residues with dormant sporangia, and spreads to the corn plants by wind and rain in the second year, and germinates and produces a large number of zoospores under suitable conditions, which swim in the water droplets on the leaf surface and form infected silks, invading the tender tissues of corn.

There are many rainy days in the middle and late stages of maize growth, especially under high humidity and high temperature, which is conducive to the occurrence of diseases. The disease is severe in low-lying land and continuous cropping land.

Before the onset or at the beginning of the onset of the disease, spray in time with 1000 times of 20 powder imitation rust Ning emulsifiable concentrate, 50 carbendazim wettable powder 500-800 times, 70 methyl tobuzine wettable powder 800-1000 times, Heguoli wettable powder 1000 times or 25 dilican demulsifiable concentrate 1500 times liquid, spray 1 time every 7-10 days, spray 2 3 times.

If an appropriate amount of foliar fertilizer, potassium dihydrogen phosphate, urea and other foliar fertilizers are added to the solution, the effect is better. When spraying, focus on spraying the middle and lower leaves and leaf sheaths.

In addition, during the growth period of corn, it is necessary to pay attention to reasonable fertilization and watering to promote the healthy growth of plants and enhance disease resistance; After the corn is harvested, the diseased residues are completely removed, and the deep ploughing is carried out in time to reduce the source of overwintering fungus.