Cotton seedling disease prevention and control is the key, what are the key points of comprehensive

The disease originates at the intersection of rhizomes and initially appears reddish-brown lesions, and during the rainy season, reddish-thick liquid flows out of the lesions, causing the seedlings to die. Cotton seedling management directly affects the yield in the later stage, so management is very important, and the following points need to be paid attention to in the general seedling stage. Due to the influence of ecological conditions and meteorological factors, cotton seedling diseases and insects have the characteristics of many types, rapid development and serious damage, which often cause lack of seedlings and broken ridges in cotton fields, and a large number of deaths in severe cases.

In the prevention and treatment, comprehensive prevention and treatment should be carried out with timely and scientific medication.

<> the characteristics of verticillium wilt rapid occurrence, serious loss, and difficult prevention and control, it is called cotton "cancer". The prevention and control of the disease should be based on strengthening field management, and improving the resistance of cotton seedlings through the selection of disease-resistant varieties, application of plantar fertilizer, early film removal, early refining of seedlings, early cultivation and other measures to improve the resistance of cotton seedlings to anthracnose will affect the growth at least and lead to the death of seedlings. When the cottonseed begins to germinate, it can be harmed by the pathogen, often causing the cotton buds to rot in a water-stained manner, and have died before unearthing, or the cotton seedlings have yellow-brown lesions on the cotyledons with reddish-brown edges; Seedlings are damaged.

Adjust the crop layout reasonably. Attach importance to the development of intercropping or flower arrangement planting between cotton and wheat, rape, corn, garlic and other crops, increase the multiple cropping index, enrich the natural enemy resources of cotton fields, maintain ecological balance, and use intercropping ecology to control aphid pests. 3 kinds of blight, anthracnose and red rot that harm the root diseases of cotton seedlings; The diseases that harm the leaves of cotton seedlings include ring spot, horn spot, stem blight, etc., and the root disease is generally the most serious.

The rate of major pest control and disposal has reached more than 95%, the application area of green prevention and control technology and the area of professional control have reached more than 20% and 25% respectively, the overall control effect has reached more than 85%, the loss rate of pest damage has been controlled within 8%, and the use of chemical pesticides has decreased significantly. In recent years, due to the adjustment of China's planting structure, global climate change, large-scale planting of cotton and other reasons, the pests and diseases of cotton fields have undergone great changes, and the production trend has gradually become complex, and cotton is an important cash crop in China.

To prevent and control cotton seedling diseases, the following comprehensive control measures should be taken. Seedling diseases such as cotton anthracnose often overwinter with spores and hyphae inside and outside the seed. Before sowing, seeds must be selected, rotten seeds, diseased seeds and miscellaneous seeds must be removed, and the seeds must be exposed for 1 2 days on sunny days to kill some of the pathogens carried on the seeds, improve the quality of seeds, promote seed ripeness, improve seed germination rate, promote seedling uniformity and seedling strength, but reduce diseases.

Red rot. Gray-red round spots appeared on the edge of the cotyledons of infected cotton seedlings, and a layer of pink spores was produced under wet conditions.

Cataplexy. The young stems and young leaves show yellow water-stained lesions, and in severe cases, the diseased parts become soft and rotten, and the seedlings wither and lodging. There are no brown sunken lesions at the base of the cotton seedlings of cataplexy.

Anthracite maggot disease. The cotyledons are yellowish-brown with reddish-brown margins. In severe cases, the cortex decays and the seedlings wither.

Carry out deep ploughing in autumn, turn the branches and leaves of the cotton field with bacteria into the land, apply foot fertilizer before ploughing, do a good job in the management of the cotton field with low terrain, and level the ground before sowing and then sow seeds. The growth period of cotton almost spans the four seasons of spring, summer, autumn and winter. So there are a lot of pests and diseases.

In the past, when our land was designated as a cotton area, the higher-level leaders also specially convened the peasants to learn the technology of planting cotton, and the technicians of the agricultural technology extension station often predicted the detection and reporting of diseases and pests, and popularized the technology of disease prevention and control.

The prevention and control of cotton diseases and insect pests should be based on the plant protection policy of "prevention first, comprehensive prevention and control", combine agricultural, physical, biological and chemical prevention and control, start from the source, prevent and control from the root, and do not rely solely on chemical control. Main prevention and control measures 1, timely ditch drainage, ridge and soil cultivation, seize the sunny day to spray cotton trace element foliar fertilizer (cotton strong king, etc.), and the seedlings should be chemically controlled in time. 2. Strengthen the maintenance of light trap moth facilities in cotton fields to ensure the effect of light trapping.

Verticillium wilt: Verticillium wilt generally begins to occur in the 4 6 true leaf stage, light yellow patches appear between the leaf margins and leaf veins on the lower leaves of the plant, and then gradually expand, the leaf color loses green and becomes light, the main vein and its surroundings are still kept green, the diseased leaves appear palm-shaped mottled, the control of cotton red spider, cotton bollworm and red bollworm is also effective, every 667 square meters with 80% dichlorvos emulsifiable concentrate 50 100 ml, with water spray, but must have a good effect in the early stage of pests.

Underground pests. Mainly grubs, mole crickets, needleworms and other underground pests are used to harm seeds and seedlings, resulting in lack of seedlings and broken strips, affecting the emergence of seedlings. Prevention and control methods:

Generally, 100 grams of carbofuran (brewed with boiling water first) are used for every 50 kg of seeds to control underground pests. Seed dressing or coating. Seed coating can be carried out with 50% carbendazim wettable powder according to seed quality or 70% thiophanate-methyl wettable powder according to seed quality.

Or mix 100 kg of cotton seeds with 20 grams of pure medicine of methacryl.

1. Reasonable layout, healthy cultivation, 2. Shovel and pupa removal, and 3. Eradicate weeds.

Fourth, deep ploughing of cotton fields is an important measure to increase cotton yield, and it is also an effective method to eliminate overwintering cotton bollworm. 5. Winter irrigation of cotton fields.

Chemical control, if there are pests and diseases found when planting cotton, you can choose to spray, and the effect is remarkable; Biological control, which can use the natural enemies of pests to control insects, the effect is also very good; There is also the use of lights, ultrasound and other physical control of pests, and the effect is also very good.

China is a big cotton producer, and everyone knows that we can't do without cotton, which is mainly used to make all kinds of clothes and many household items. However, in the process of cotton growth, many diseases will be encountered, so diseases will have an impact on the quality and yield of cotton.

1.Cotton wilt

Cotton wilt disease is a common and major disease of cotton, which has serious harm to cotton production and causes large losses. Cotton wilt disease mainly affects cotton seedlings, and the disease forms are various, some leaves appear yellow reticulated, and after the leaves wilt, some leaves turn yellow or purple, but the outcome is leaf wilting and plant death.

Prevention and control methods:Fusarium wilt can safely overwinter in soil and fertilizer, and as new plants continue to spread the following year, seeds, soil, fertilizer, etc. should be disinfected before planting. Reasonable dense planting, fertilization, polymyxin agents can be used to dilute root irrigation or spraying in the early stage of the disease.

2. Cotton verticillium wilt

There is only one word difference between cotton verticillium wilt and wilt, we can get from the name, cotton verticillium wilt occurs when the leaves lose water, the leaves are yellow and blocked, and with the spread of the disease, the disease gradually expands. After a long period of drought and heavy rainfall, the leaves suddenly withered and then fell off.

Prevention and control methods:Choose varieties with strong disease resistance, avoid continuous cropping, good cropping and other crop rotation, can reduce the occurrence of diseases, spray growth regulators such as shrinkage at the current budding stage, and regularly spray daidzein manganese-zinc or methyl mercaptan and other agents, which has a preventive effect.

3. Cotton aphid

Cotton aphid mainly harms cotton seedlings, aphids suck the sap of seedling leaves, causing seedling leaf curl, resulting in normal growth and development, affecting the flowering boll stage, resulting in late maturity and reduced yield of plants.

Prevention and control methods:Spray is used with pesticides that are less harmful to plants.

4. Cotton bollworm

Cotton bollworm mainly affects the budding stage of cotton. Cotton bollworm feeds on cotton buds, bolls and young stems, resulting in flowering failure, boll leaf shedding and boll rot, which ultimately affects the quality and yield of cotton.

Prevention and control methods:Spray the same insecticide that is less harmful to plants.

Diseases and insect pests at the seedling stage of cotton are important factors restricting the early emergence of strong seedlings in cotton fields. There are two main types of seedling diseases: root diseases and leaf diseases. Field management should be strengthened, and cotton should be cultivated in depth and diligently after emergence, so as to increase soil temperature, reduce soil moisture, and aerate the soil to facilitate root development.

For insect pests, only drugs can be used**, for example, the control of cotton aphid can be sprayed on cotton leaves and stems with imidacloprid or acetamiprid.

Improving soil fertility and soil fertility can effectively control the occurrence of seedling diseases by increasing agricultural measures such as increasing farm fertilizer, vigorously promoting straw returning to the field, and intensive cultivation, so as to fertilize the soil, improve the soil, and increase soil permeability. The selection of disease-resistant varieties and the selection of disease-resistant varieties with excellent seed coating agents is the fundamental measure to prevent diseases. Years of trials have shown that Syngenta's Ready-to-Eat seed coatings are effective in controlling cotton seedling diseases.

When planting cotton, spray some pesticides on the cotton, so that it can be prevented. Spray some pesticides, renovate the soil, clean the surrounding area, prune the branches, and put more fertilizer.

It is necessary to do a good job of prevention, to ensure soil fertility, to do a good job of watering and fertilization, but also to prune branches and leaves in a timely manner, use pesticides and fertilizers, and do a good job of ventilation and loosening the soil.

shrinkage; When the seedlings grow 3 to 5 true leaves, the young leaves at the growth point are shriveled and deformed, and the mesophyll is blister-like and convex, and the symptoms are very similar to the damage of cotton aphid, but there is no cotton aphid on the back of the leaves, the internodes of the plant are shortened, the leaf color becomes darker, and generally does not die, and it is often mixed with the yellow reticulation type. Do a good job of quarantine and protect disease-free areas. Quarantine is an effective measure to prevent problems before they occur.

When transferring seeds, it is necessary to carry out the procedures for the allocation and quarantine of seeds. Cotton seeds in the sick area should be disinfected first, and the cotton seeds in the isolation area should be planted for one year to prove that there are no pathogens before they can be planted in the disease-free area.

Some plants are sick on one side, but the other half can still grow, forming half wilting. Severely diseased plants die early, and mildly diseased plants can survive with disease, but the yield is seriously affected. The stems, petioles, and ducts at the roots all turn brown.

If it rains heavily in autumn, a pink mold layer is formed on dead stems and nodes. Cotton topping time should be determined according to the specific situation of the growth of cotton fields, the cotton fields with weak growth should be topped early, and the cotton fields with more vigorous growth should be topped later, but all cotton fields should be topped before August 15.

Cotton yellow wilt is the most likely disease of cotton after topping when growing into an adult plant, and yellow wilt is extremely harmful to cotton, which can cause a large number of dead seedlings of cotton and dead plants. Pay attention to the application of phosphorus and potassium fertilizers, at this time the absorption of cotton phosphate fertilizer and potassium fertilizer reaches its peak, which is the maximum absorption and utilization period of cotton for phosphate fertilizer, if there is a lack of phosphorus at this time, it will have a very serious impact on the yield.

The disease is characterized by the appearance of light yellow leaf spots between the leaf edges and leaf veins of the lower leaves of cotton at the beginning, and then slowly spread, the leaf color gradually becomes lighter and the mesophyll will become thicker, the edge is curled downward, and the leaves will slowly fall off from the bottom to the top, and finally only a few leaflets on the top of the plant remain, and the cotton will be scarce and will split in advance. If you are yellowing and wilting, you can use carbendazim twice to see if you have blight. There are also insect infestations, such as concentration insects and cotton spirit insects.

I took the medicine for three days in a row.

This is a common disease of cotton, the pathogen is a fungus, after infection, it will cause the leaves to die or fall, and the whole growth cycle of cotton is prone to cotton wilt, so we should pay attention to prevention and control.

Cotton wilt is a common disease during the cotton planting period. The pathogen is a fungus, Fusarium oxysporum (wilting specialized type), which mainly harms the vascular bundles and other parts of cotton, causing leaf death or falling off. Depending on the location of the hazard, it can also be referred to separately by different special names.

The disease can be prevented by spraying pesticides or planting management.