How to identify peanut leaf spot? What are the prevention and control methods of peanut leaf spot?

There are two key types of peanut kernel brown spot disease, including peanut kernel brown spot and peanut brown spot disease. The germs spend the winter in the field according to the remains of diseased plants! In the second year, when planting, the temperature is suitable (above 10), and when the temperature is high, the fungus will spread widely, and it may occur at the seedling stage, and the performance is that leaf spots appear on the leaves, causing the initial leaf withering immediately!

The frequent stage of peanut kernel brown spot disease is the second half of peanut growth, and the damage is generally greater in July and August, especially in continuous rainy days, the disease is especially serious! For fields with obvious brown spot disease in the past, it is necessary to spray pesticides immediately after the rain to prevent it. There are many disadvantages of continuous cropping of peanut kernels, and only effective rotation can farmers get rich; After planting peanuts, it is advisable to rotate with gramineae green plants, which include rice, wheat and bud rice.

And this kind of grass green plant rotation, can reasonably improve the structure of the soil, the nutrient elements in the soil to complement each other, to improve the yield of a good harvest to lay a good foundation. Peanut kernel brown spot is a general term for leaf black spot, brown spot and net spot, and pests and diseases can be mixed and produced on the same plant beads and even the same leaf. Generally, the following types of conditions are easy to cause peanut kernel brown spot disease, such as poor soil moisture, poor fertilizer efficiency, poor peanut seedlings, due to the weak resistance of the seedlings themselves, a little pathogenic bacteria can be susceptible, in addition to the poor rotation of the land, it is also easy to cause disease.

For example, if peanuts are planted for two years on this plot, not only brown spot disease, but also other pests and diseases, pests and diseases are also prone to occur. In addition, the temperature is between 25 degrees and 30 degrees, which is more likely to get brown spot because it is the right temperature, and in addition, continuous rainy days will also cause brown spot disease to be more serious. Improved varieties of peanut kernels, especially those that resist the ability to work, are not required to be used in the field of problems, or to plant alternate species in alternate yearsPrevent the decline of disease resistance due to a single category.

Under normal circumstances, the lesions are relatively large, the diameter can reach about 4 10 mm, the color is relatively light, and the initial lesions are obvious yellow halos; First of all, we should choose some high-quality varieties, clean up and reduce the number of pathogens, destroy these diseased peanuts in time, and do a good job in field management, and apply more organic fertilizer.

Peanut leaves, petioles, stems, ovary leaves, affect nutrients, plant early withering, resulting in fruit is not full, oil content is reduced, you can improve the soil, improve the cultivation conditions, add organic farm fertilizer, you can buy some insect inhibitors, through the prevention and control of pesticides, or buy some sprays.

After the peanut is unearthed, the adults and nymphs will be exhausted on the top of the peanut and the back of the young leaves, and there will be a large amount of honeydew adhering to the peanut, and there will be rot of the stems and leaves; The use of natural enemies for the control of peanut aphids, can also use the characteristics of aphids tend to yellow to set up dark yellow tone and paint coating board in the field, can also place yellow dishes to trap, can also use some pesticides to kill pests and diseases.

Peanut brown spot is not purely a pest and disease, it is divided into:Brown spot, brown spot and net spot. It is mainly to damage the leaf stem of peanut kernels, once the peanut kernels are affected, it will cause the leaves to fall off, which seriously endangers the production and quality of peanut kernels, which is one of the main factors restricting peanut production. More serious peanut fields can lead to a 40 percent yield limit.

Despite the brown spot disease showingThere are many types, but comprehensive prevention and control are also needed in prevention, <>

before the actual effect occurs. First of all, it is necessary to use the improved varieties of peanut kernels, especially some varieties that resist the ability to work, and it is proposed that the application of peanut seeds should not be kept for the problem of Tian Kuai, or the planting of alternate species in alternate years, so as to prevent the decline of disease resistance caused by a single variety. Second, it is necessary to strengthen cultivation technology.

Conditional fields can be planted in 2 years with a stubble rotation, especially in the rotation with soybeans and buds, and the actual effect will be stronger. Rational application of chemical fertilizers, should prevent the use of compound fertilizers with high nitrogen, with three 15 balanced fertilizers and 16-14-15 secret recipes are more effective, to spray leaf fertilizer under appropriate circumstances, <>

In particular, the peanut kernel three-time medicine that is in the market demand at this stage can have the effect of preventing brown spot disease and improving the disease resistance of peanut kernel, so as to increase the yield. Most of the pests and diseases were impregnated in the second half of peanut kernels, which was related to disease resistance in the early seedling stage. Yellow leaves are more susceptible to brown spot than new shoots.

So how to prevent brown spot on peanut kernel leaves? When the peanuts are harvested, the dead branches and leaves are eliminated immediately to reduce the number of pathogenic bacteria. The method of seed dressing is used to prevent diseases at the seedling stage.

For the early flowering stage of peanut kernels, the Qi needle stage, and the Pengda stage, the drug is taken. In the early flowering period it is critical to prevent youngSeedling pests and diseases, benzene can be used. Azoxystrobin is carried out to prevent, and with molybdenum fertilizer to promote rhizome nitrogen-fixing bacteria, it is best to add another bag of brassinolide to adjust the growth and development.

In the peanut kernel needle stage and fruit expansion stage, pyraclostrobin can be selected to carry out the prevention of brown spot disease, and it is best to mix tebuconazole or fluconazole, which can play the effect of prevention and treatment of brown spot disease, and the actual effect is good.

The main symptom is actually to cause those leaves to appear spotted and dry up, and finally the whole branch will wither, to prevent this disease, generally speaking, in advance to choose antibacterial varieties, the next step is to strengthen the management of the field, and at the same time to spray drug control.

There are yellowish-brown or rust-colored spots, which gradually enlarge, starting with the lower old leaves and then spreading to the upper leaves; Be sure to keep the soil moist, fertilize properly, and have plenty of light, and regularly prevent diseases and pests on the plants.

The leaves will be yellow, will droop, the growth rate of peanuts is very slow, and the size is very small, very not full; It is necessary to water more, fertilize more, spray nutrient solution, spray disinfectants, the temperature should be suitable, and there should be a certain amount of sunshine.

The lesions on the leaves are round, dark brown, with many small black dots on the back; Try to choose some disease-resistant varieties to enhance field management, apply more fertilizers, and minimize irrigation.

Peanut leaf spot disease is well controlled with propiconazole. The specific drugs for peanut leaf spot disease include benzprothramazole, difenoconazole strobin, tebuconazole carbendazim, spizolestostrobin dysenlian, thiamethoxychloride, Chunlei king copper, copper hydroxide, etc. Foliar sprays can be applied every 7-10 days after the onset of the disease, and 2-3 consecutive applications can control the onset of the disease.

Peanut leaf spot is divided into peanut black spot leaf spot and peanut brown spot leaf spot, which is a disease that occurs in peanuts caused by Cercospora globae and Cercospora peanis, respectively.

Leaf spots are mainly on both sides of the leaf front and back of the late plum branches, round or nearly round, the size of millimeters and millimeters, and the lesions expand and fuse into large irregular plaques. The petioles, stems, and flower axes2 are infected, and the lesions are linear or oval, dark brown to black-brown, sometimes with a light yellow water-stained halo on the periphery.

The use of imported anti-spot spirit "32 grams per mu with 60 liters of water, sprayed twice from mid-July to early August, the disease prevention effect is reached, and it will not induce the development of rust in the later stage. It can also be applied to 500 times of anti-kuning solution from the end of June to mid-August, foliar spray once every 15 days, 75 ml each time, a total of 4 sprays. And in the first foliar spray, 100 liters of liquid medicine was used to irrigate the pier, and the control effect was the best.

1.Agricultural control.

1) Remove the diseased and residual bodies: When harvesting peanuts, collect the diseased residues or fallen leaves as much as possible and use them as roughage for livestock. Treat the stacked peanut seedlings in time before sowing to eliminate the source of primary infection.

2) Crop rotation: Peanut leaf spot disease has a single host and only infects peanuts, so it has a good preventive effect on rotation with sweet potato and wheat crops in alternate years or with rice in water and drought rotation.

2.Pharmaceutical prevention and control.

During the growth period of peanuts, spray 1 time every 10 15 days according to the condition from the beginning of flowering, spray 2 4 times in a row, and spray 50 75 liters of liquid solution per mu each time, which can be reached.

to the effect of preventing and controlling the development of diseases. Commonly used agents are: 50% carbendazim wettable powder 1500 times liquid, 75% tobuzin wettable powder 1500 2000 times liquid, 80% mancozeb 400 times liquid, 75% chlorothalonil wettable powder 600 800 times liquid, Bordeaux liquid 200 times liquid (copper sulfate:

quicklime: water is 1 2 200).

Nano mineral oil can be very effective in prevention and control, and the effect is immediate.

The easy and economical one is still flusilazole... Weiwei agricultural materials, agricultural materials experts around you **!

Raising longevity flowers, "leaf spot disease" is treated with this method, the effect is fast, and the new branch flower buds develop quickly.

Peanut leaf spot disease, foliar spraying of difenoconazole. propiconazole, or difenoconazole. Azoxystrobin, or tebuconazole.

carbendazim, or pyraclostrobin. Dai Senlian, or thiazine copper, or spring thunder king copper, or copper hydroxide, etc., the effect is very good. Foliar spraying every 7 to 10 days after the onset of the disease, 2 3 sprays in a row, can control the onset of the disease.

Add potassium dihydrogen phosphate and spray together, the control effect is better. In addition, plants infected with leaf spot disease should strengthen fertilization management, increase organic fertilizer and phosphorus and potassium fertilizer, in order to restore growth potential, enhance disease resistance, in order to speed up the return to normal growth.

To prevent early spot disease of peanuts, it is necessary to fertilize peanuts in time, spray pesticides, and kill early spot disease of peanuts in the bud.

First of all, we must ensure that peanuts are safe and healthy, and at the same time, we should regularly apply anti-pest medicines, so as to effectively prevent them.

It is best to plant peanuts and other crops separately, once the disease occurs, the use of plant-specific insecticides should be used in a timely manner, evenly sprayed on the plant leaves, and watering should not be done during the medication, otherwise there is no effect.

Prevention and control methods of peanut leaf spot: (1) Breeding disease-resistant varieties.

The standing vine varieties are more resistant to disease than the creeping varieties and can be adopted according to local conditions.

2) Agricultural control.

Improve the soil and apply sufficient basal fertilizer to promote the growth of peanuts, thereby improving disease resistance. After the peanut is harvested, the diseased leaves of the residual plants in the field are removed, and the seeds are buried deep or used as feed to reduce the source of bacteria in the field, and it can also be rotated with gramineous crops for 2 to 3 years.

3) Pharmaceutical prevention and control.

When the rate of diseased leaves reaches 10% 15%, or the disease index is 3 5, the control is started. The agent is sprayed with 75% chlorothalonil 75 100 grams, or 40% phytophthamphen 70 100 grams, or 50% carbendazim 50 grams per 667 m 2 (mu), sprayed once every 7 10 days, and sprayed 2 3 times in a row.