What are the ways to prevent cabbage virus disease early and eliminate the source of the disease?

What are the ways to prevent cabbage virus disease early and eliminate the source of the disease?

Chinese cabbage virus disease ** and symptoms, the leaves are thick, light green or yellow, green mottled, the leaves of the seriously diseased plant are shrunken into a clump, the leaves are hard and brittle, the leaf surface is dense with brown spots, and there are brown necrotic spots on the veins on the back of the leaves, and cracks appear, severe dwarfing, deformed, and no balls. Mild disease plants are deformed, dwarf is mild, sometimes half of the leaves are wrinkled, and some of them can form balls, and there are often many gray spots on the leaves in the balls.

A The roots of the seriously diseased plant are mostly underdeveloped, the beard is few, and the cut surface of the diseased root is yellowish-brown. If the seed plant is seriously damaged, the peduncle dies without extraction, the disease is light, the peduncle is bent and deformed, the height is less than half of the normal, and there is a longitudinal and horizontal crack on the peduncle. The flowers are prematurely sensitive, rarely fruit, or the fruit pods are small, the grains are not full, the germination rate is low, and the germination is inferior.

1. Symptoms of Chinese cabbage virus disease: When Chinese cabbage seedlings are sick, the heart leaves produce bright veins or leaf veins lose green, and produce mottled light green and dark green. And the shrunken leaf curls, the dorsal veins of the leaves produce brown necrotic spots or streaks, resulting in the shrinkage and unevenness of the leaves.

The leaves of the adult plant become hard and brittle, the color gradually turns yellow, and the whole plant rapidly dwarfs, stops growing, and cannot be coated normally. Some of the outer leaves are normal, but the inner leaves have brown necrotic spots that are inedible.

b2. Pathogenesis: Chinese cabbage virus disease is caused by viruses and is transmitted by aphids in the field. Chinese cabbage 6-7 leaves before the seedling stage is susceptible to disease, called the sensitive period of susceptibility, but also the danger period of aphid poisoning, that is, the effective transmission period, during this period, the earlier the susceptibility, the more serious the disease, the greater the loss, and then the disease, the incidence is milder.

After sowing, Chinese cabbage encounters high temperature and drought, high ground temperature or long duration, which is conducive to the reproduction and activity of aphids, but the growth and development of Chinese cabbage roots are inhibited, and the resistance is reduced, which is prone to disease at this time. In addition, early sowing, many aphids, coupled with extensive management of vegetable fields, low terrain and unventilated or dry soil, lack of water, lack of fertilizer when the disease is serious.

c. Prevention and control methods: choose varieties that are resistant to viral diseases. Sow seeds at the right time.

According to the local climatic characteristics, the sowing date of autumn Chinese cabbage in North China should be after August 4, and the later the sowing, the lighter the disease. Control of aphids. After the autumn Chinese cabbage is sown and seedlings emerge, aphids should be controlled every 7 days or so until the cluster stage.

Pharmaceutical prevention and control. Generally, before the onset of the disease or in the early stage of the disease, the drug prevention and treatment is started, and it is sprayed once every 10 days, 2 or 3 times in a row. Commonly used agents are:

500 times of 20% virus A wettable powder, 500 times of Baivenolin No. 1, 1 000 times of phytoxin emulsion, 200 300 times of 5 Qu poison clear water, 300 times of anti-poison No. 1, and 100 times of 83 anti-agent.

Chinese cabbage virus disease, the prevention and control method can be generally before the onset or early stage of the disease to start the prevention and control of pesticides, spraying every 10 days, 2 3 times in a row. Baivenolin No. 1 500 times solution, 1 000 times phytolin emulsion, amino-catenin and other agents for prevention and control.

Chinese cabbage virus disease, prevention and control methods: Amino-oligosaccharides, morpholinoguanidine hydrochloride, amino-catenin and other agents can be used for prevention and control in the early stage of the disease, 2-3 times in a row. Pay attention to the prevention and control of aphids with acetamiprid, pymetrozine and other agents to prevent the spread of viruses.

When encountering unfavorable weather conditions such as high temperature and drought after Chinese cabbage sowing, aphids multiply in large quantities and spread poison, and the disease is serious. In particular, the seedling is susceptible to virus diseases before the six-leaf stage, and the earlier the onset of the disease, the more serious the damage. Therefore, the key period for the prevention and control of Chinese cabbage virus disease is the seedling stage and the early growth stage, in these two periods, it is necessary to control aphids in time, and these symptoms of Chinese cabbage are caused by virus infection.

These viruses can overwinter on seed skins, weeds, and then spread by aphids. When encountering unfavorable weather conditions such as high temperature and drought after Chinese cabbage sowing, aphids multiply in large quantities and spread poison, and the disease is serious. In particular, the pre-six-leaf stage of seedlings is the susceptible period of viral diseases.

Agricultural measures Disease-resistant varieties are selected according to local conditions. Adjust the layout of vegetables: reasonable intercropping, intercropping and rotation, and timely uprooting of diseased plants.

Late sowing at the appropriate time: avoid high temperature and aphid rampant season, squat seedlings in a timely manner, and squat seedlings or not squatting seedlings in the rosette stage. Apply sufficient basal fertilizer:

Increase the application of phosphorus and potassium fertilizers, and control the application of less nitrogen fertilizers.

Timely control of aphids at the seedling stage: Since Chinese cabbage virus disease is transmitted by aphids, the prevention and control of aphids at the seedling stage of Chinese cabbage is an important measure to prevent and control Chinese cabbage virus disease. For the control of aphids at the seedling stage, you can choose 10% imidacloprid wettable powder 1 500 times liquid, or 3% acetamiprid or 50% aphid carb wettable powder 2000 3000 times liquid, in the selection of disease-resistant varieties, appropriate sowing, to ensure that Chinese cabbage has sufficient growth period under the premise of drought and little rain years, in case of drought and little rain, pay attention to watering at the seedling stage to reduce soil temperature and protect roots and strong seedlings.

The disease can occur from the seedling stage to the heart stage, at the onset, the leaf skin is shrunken, uneven, especially the heart leaf is spastic, and the yellow and green flowers and leaves appear, the leaf veins produce brown necrotic spots or stripes, and sometimes the leaves are tilted to the side. When the plant is seriously shortened, it can not be cored, and the layout is reasonable, and the non-cruciferous vegetables are rotated for 2-3 years; Advocate intercropping with other crops to effectively reduce aphid transmission. Try not to grow next to cruciferous vegetables.

Pesticides. Because pesticides can be a good way to prevent and improve viral diseases, pesticides can be used to prevent and control them.

You can buy some special pests and diseases drugs, spray preventive drugs around the soil, is the cabbage, and also fertilize and water.

Fertilization should be applied, pests and diseases should also be eliminated, and disease-resistant varieties should be selected, so that the virus of bok choy can be well controlled, and the effect is also very good.

It often forms depressed necrotic spots on the veins on the back of the leaves, and the plants are deformed, dwarfed, and do not bulb or have a soft and empty shell feeling. Diseased plants sometimes appear crooked, half of them are shrunken, half of them are withered, and half of them are balls, so vegetable farmers call them cabbage half crazy. For the prevention and control measures, it is recommended to take agricultural, physical and biological control as the main and chemical control as the supplement.

First of all, growers need to rotate crops reasonably to avoid continuous cropping of cruciferous vegetables {During the growth of cabbage, it is necessary to pay attention to removing diseased leaves in time.

As much as possible, choose the fields of wheat, rice, and leguminous crops to plant cabbage, and avoid continuous cropping with Solanaceae, melons and other cruciferous vegetables; Turning the ground as soon as possible to promote the decomposition of diseased and disabled bodies; Planting with deep furrows and high compartments; selection of disease-resistant varieties; sowing at the right time; : 500 times of 75% chlorothalonil wettable powder, or 150 200 times of 40% aluminum triethylphosphonate wettable powder, or 600 800 times of downy mildewcarb, or 64% frost. Manganese-zinc wettable powder 500 times liquid spray control.

In summer, the climate environment of high temperature and high humidity is prone to disease, and in addition, continuous cropping and improper fertilization will also lead to disease. The same planting of soil and seed disinfection treatment, scientific and reasonable fertilization, a balance of fertility, difenoconazole, thiamium copper spraying control and selection of high-quality and disease-resistant Chinese cabbage varieties. High-quality Chinese cabbage has disease resistance, and before planting Chinese cabbage, the seeds are coated with antibiotics to prevent Chinese cabbage root rot and soft rot.

Pests of cabbage can be divided into pests at the seedling stage and pests at the bulbous stage. Insect pests at the seedling stage, with yellow-striped jumping beetles. Cabbage worms.

ground tigers, etc. The insect pests in the bulbous stage of cabbage are mainly aphids. This aphid directly harms cabbage.

Mild ones cause wounds and plant impacts. Large white powder infected with downy mildew, in the early stage of the disease, there is a white mold layer on the back of the leaf, on the front of the leaf, there will be light yellow or yellow-green lesions, due to the restriction of the leaf veins, the lesions will show an irregular shape.

The key point of Chinese cabbage virus disease prevention and control is to choose disease-resistant varieties, when planting, to apply foot fertilizer, increase phosphorus and potassium fertilizer, control the amount of nitrogen fertilizer, encounter the dry season must be watered frequently, cool and moisturize, promote the growth of cabbage roots, so as to improve the ability to resist disease.

1. Choose disease-resistant varieties: Yangchun, Jianchun, Xiayang 50, Xiafeng, Jinlu 55, etc. 2. Late sowing at the appropriate time, so that the sensitive period of the disease is postponed to the cold season, so as to avoid the onset conditions and reduce the onset of the disease.

3. Avoid continuous cropping with cruciferous vegetables. Diseased plants are found in the field and removed in time to reduce the spread of pathogens.

The virus overwinters in a variety of ways, some on seeds, perennial weeds in the field, and the remains of diseased plants, and some overwinters in protected areas. The following year, it was spread by aphids and direct contact. High temperature and drought are conducive to the occurrence of aphids and the occurrence and epidemic of viral diseases.

The disease is serious in the case of heavy cropping, adjacent crops, insufficient soil fertilizer, and poor crop growth. It is susceptible to disease at the seedling stage before 6-7 leaves of cabbage, and the susceptibility decreases after the rosette stage. There were also significant differences in disease resistance among different cultivars.

Chinese cabbage is prone to virus hazards in high temperatures, rainy or little rain. Chinese cabbage is susceptible to viral diseases when there is drought and little rainfall and aphids are frequent. Chinese cabbage is prone to occur under high temperature and high humidity conditions.

The occurrence and prevalence of the disease are mainly related to climatic conditions, cultivation management, and variety disease resistance. 1.Climatic conditions, with the amount of rainfall and the number of days of rainfall being the most critical.

2.Tillage and cultivation management, cruciferous vegetables are adjacent to each other or with other toxic plants, and serious diseases occur; On the contrary, the onset of the disease is mild. 3.

There were significant differences in disease resistance among different varieties. Among Chinese cabbage, the Qingbang variety is more resistant to disease than the white cabbage; Hybrid varieties are more resistant to disease than general varieties.

At the seedling stage, the heart leaves are bright veins or leaf veins lose green, and then produce uneven green spots or flower leaves, the adult leaves are seriously shrunk, and many small brown spots are born, and the plants are obviously dwarf and deformed, and do not ball or ball loosely. Yellow-green mosaic symptoms are also present, with brown necrotic spots or streaks on the veins, and sometimes the leaves are tilted to one side. When the plant is severely shortened, it can not be cored, and although it can be cored in the middle and late stages of disease, the necrotic point inside the leaf bulb will rot, and even if it does not rot, it will lose its commercial value.

When the cabbage encounters continuous rain or sudden high temperature weather, it is easy to rot roots and yellow leaves. Therefore, some potassium dihydrogen phosphate plus carbendazim should be sprayed for prevention. When the above diseases occur, spray with Jinggang thiofir or thiophanate-methyl plus potassium dihydrogen phosphate mixed with water or water to water the roots**.

Advocate the priority use of "four inducements and one network" green prevention and control technology, when using chemical pesticides, should purchase three complete certificates of agents, and strictly follow the relevant requirements when using. Pesticides should be used alternately, and the safety interval should be strictly controlled.

The control of Chinese cabbage insect pests should adopt comprehensive control, physical control, chemical control, and agricultural comprehensive control: first, it should be rotated with non-cruciferous crops; the second is to remove the diseased leaves and old leaves in the garden in a timely manner, and make centralized treatment; the third is to set up insect nets; Fourth, trapping adult insects. Then in the agricultural prevention and control measures, the main thing is to deal with the weeds in the cabbage planting plots, of course, there are some dead seedlings and seedlings eaten by such pests, which must be pulled out in time, and then used.

Pests are controlled by using pathogenic microorganisms that cause fungi, bacteria, viruses and other groups. Insect control with bacteria is a very safe means of control, there is no harm to people, livestock, crops and microorganisms, is conducive to maintaining ecological balance, and the control effect is very good, the use of one percent of lime water or 3% of superphosphate extract, in the peak or peak period of cabbage worm oviposition, foliar spraying twice, can inhibit its oviposition, to achieve the purpose of prevention and control.

Strengthen on-site management. The epidemic year of the disease was changed to direct seeding and reasonable dense planting; Pay equal attention to basal fertilizer topdressing, timely topdressing, pay special attention to fertilization at the lotus sitting stage and fertilization at the ball sitting stage, spray foliar nutrients and zinc phosphate aqueous agent, and promote the early growth and rapid growth of plants; Covering gauze with a small arch canopy has an obvious effect on disease prevention and yield increase.

1.selection and selection of disease-resistant varieties; 2.Strengthen field management, pay equal attention to base fertilizer and top dressing, and timely top dressing; 3.spraying control; 4.Do a good job of avoiding aphids, trapping aphids, and preventing aphids.

Pesticides. Because after my cabbage is sprayed with pesticides, it will not be able to get sick from viruses, so it should be treated with pesticides to prevent and control it.

Cabbage virus disease is caused by the production of aphids in the growth stage of cabbage, and the aphids transmit the virus, resulting in cabbage being attacked by pests and diseases. The method of prevention and control, we can use the aphid elimination agent to spray on the cabbage at the seedling stage of Chinese cabbage, so as to eliminate the effect of aphids.

If the bacterial infection is generated, antibacterial seeds should be selected, disinfected before planting, and the diseased Chinese cabbage should be pulled out and destroyed after the disease occurs, and antibacterial drugs should be sprayed in time.

Chinese cabbage virus disease, also known as solitary disease, "convulsive disease", is the most common occurrence of Chinese cabbage production, the most serious, one of the most difficult diseases to prevent and control, and downy mildew, soft rot and called the three major diseases of Chinese cabbage, the general epidemic year can cause about 10% of the yield loss, some reoccurring years can reduce the yield by more than 30%, serious plots can even lead to no harvest, seriously affect the yield and quality of Chinese cabbage. What are the harmful characteristics of Chinese cabbage virus disease and how to prevent and control it?

Symptoms of harm. Chinese cabbage virus disease mainly occurs in the Chinese cabbage cluster to rosette stage, especially in the 6 10 leaf stage of Chinese cabbage, which is called the sensitive period of susceptibility. At the seedling stage, the heart leaves produce bright veins or leaf veins lose green, and produce mottled light green and dark green.

And the shrunken leaf curls occur, and the dorsal veins of the leaves produce brown necrotic spots or streaks, resulting in the shrunken and uneven leaves. The disease occurs at the adult stage, the leaves become hard and brittle after being damaged, the color gradually turns yellow, the whole plant rapidly dwarfs, grows slowly, or even stops growing, and cannot be coated normally. Some of the outer leaves are normal, but there are brown necrotic spots on the inner leaves, the leaves of the seriously diseased plants are shrunken into clumps, the leaves are hard and brittle, the leaf surface is densely covered with brown spots, and there are brown necrotic spots on the veins on the back of the leaves, and cracks appear, and the plants are seriously dwarfed, shrunken and deformed, and do not bulb.

Loss of edible value and commodity value.

Causes. After sowing cabbage, in case of high temperature and drought, the ground temperature is high or lasts for a long time, the growth and development of the root system is inhibited, the aboveground part stops growing, the plant disease resistance decreases, and the virus incubation period is shortened. The peak occurrence period of aphids in spring and autumn coincides with the susceptibility period of cabbage, and it is easy to develop the disease when the temperature is 15 20 and the relative humidity is 75%.

Generally, the earlier the sowing date, the more serious the disease, the greater the damage, especially the high soil and temperature before the seedling 7 leaves, drought is the most susceptible; In adjacent plots with cruciferous vegetables, viral diseases can be transmitted to each other, which can also lead to serious morbidity; In addition, there were significant differences in the resistance of different Chinese cabbage varieties to viral diseases.

Prevention and control methods. (1) the first choice of disease-resistant varieties: Chinese cabbage virus disease once infected is difficult to completely **, so the selection of disease-resistant varieties is the most effective, simplest, the best way to prevent virus diseases, there are a large number of disease-resistant varieties in production, according to different planting seasons, different plant methods and different regions, choose suitable disease-resistant varieties.

2) timely prevention and control of poison-transmitting insects: aphids, whiteflies and other stinging and sucking pests, is the most important poison-transmitting insects on cabbage, in the Chinese cabbage seedling stage must pay attention to the prevention and control, can be used in Chinese cabbage seedlings and planting, with 2% thiamethoxam granules respectively to the seedbed and planting holes to prevent pests from harming seedlings and spreading viruses, cut off the transmission route.

3) Spraying prevention and control: virus diseases should be mainly prevented, which can be sprayed evenly with 75 100 grams of 6% oligosaccharide and catenin wettable powder at the seedling stage, cluster stage and rosette stage, or 80 120 ml of 1% lentinan polysaccharide water agent, mixed with 30 kg of water, which can effectively prevent the occurrence of viral diseases.