What are the characteristics of cotton Verticillium wilt

Hazard characteristics: 1. Cotton can be infected with hazards throughout the growth period, forming a peak incidence around July 20, and forming a peak incidence of the whole year at the end of August and early September. 2. There are 3 types of common symptoms:

One is macular type. The disease starts from the bottom up. The mesophyll part between the edges of the diseased leaves and the veins of the leaves has yellow to brown patches locally, with irregular shapes, and the leaf edges are rolled up into palm-shaped yellow spots, and the leaves do not fall off and do not die in the early stage.

The second is the leaf withering type. The leaves appear as local or palmate spots, and the leaves fall off after death, and generally do not form bare stalks. The third is deciduous type.

Symptoms appear in the upper lobes. The leaves are wilted and fall off rapidly, and the plants become bare stalks before they die, and the vascular bundles show brown lesions when the roots, stems, and petioles are dissected.

FYI.

Cotton Verticillium wilt prevention and control methods:

1. Chemical defense

Fungicides can be allicin, 70% sodium disulfon, 3% polyantimycin, 36% cotton withered, 70% chlorfen, etc.; Nutrients can be selected potassium dihydrogen phosphate, potassium fulvic acid or other phosphorus and potassium fertilizers; Promoting regulators can be used brassinolide, sodium renitrate, etc.

Chemical control methods have strong timeliness and high stability, but the use of a large number of chemical agents will accumulate in the food chain cycle, which will not only make the environmental quality worse, but also endanger human body functions. Long-term use of chemicals kills other beneficial bacteria.

While preventing disease, it can also cause drug resistance of pathogenic bacteria. At present, other control methods are actively being sought to replace the use of chemical agents.

2. Biological bacteria control of cotton wilt wilt technology

Biological bacteria have antagonistic effects on pathogenic bacteria, and can improve soil and promote crop growth, and have multiple modes of action in the prevention and control of cotton Verticillium wilt disease.

Biocontrol bacteria produce substances that have a killing effect on pathogenic bacteria, such as Bacillus subtilis, antibiotics, bacteriocins, ferrophilin and other metabolites. The applied biological bacteria will form a dominant flora in the soil, quickly occupy all sites on the plant body that may be infected by pathogens, compete for nutrients and oxygen of Verticillium wilt pathogens, so that it has nowhere to survive.

Biocontrol bacteria can open the secondary metabolism of plants and produce phenols, flavonoids, alkaloids, etc., which have a direct bactericidal effect. Biocontrol bacteria can increase the production of indoleacetic acid, ethylene and other growth regulators in plants, enhance root tip vitality, promote the growth and development of crops, and indirectly improve the disease resistance of crops.

Hazards and losses of cotton Verticillium wilt:

Cotton Verticillium wilt has a great impact on the growth and development of cotton plants. After the infection of cotton plants, the leaves turn yellow and dry, resulting in less boll formation, reducing the weight of boll formation, causing a large number of leaves to fall off, and even all leaves to fall off, no boll formation, boll falling off and drying, cotton yield and quality are reduced.

Generally, the yield will be reduced by about 10-30%, and in severe cases, the yield will be reduced by more than 80%, or even no harvest. It often brings heavy losses to the peasants and makes them lose all their money in a year, so it becomes very crucial to do a good job in prevention and control.

Verticillium wilt has occurred in my cotton field, how to get there**?

Answer: As the saying goes, people who are in good health do not get sick easily. The same is true for trees, which can minimize losses due to disease by strengthening field management during the growing season of cotton under the premise of using disease-resistant varieties.

Deep ploughing of the soil after cotton harvest in autumn can reduce the number of Verticillium wilt pathogens in the tillage layer, and reduce the incidence and severity of plant diseases. In deep soils, plant debris and pathogenic bacteria decompose rapidly, which is good for maintaining soil health. Improve the ecological environment of cotton fields, plant and weed in time, maintain air moisture content, prevent excessive moisture in cotton fields, change the permeability of soil, enhance the ability of cotton to transport nutrients, and reduce the occurrence of diseases.

Nitrogen, phosphorus, and potassium can be used for fertilization in cotton fields. The ratio of n, p, and k is: 1.

This ratio of fertilization can effectively control diseases and increase cotton yield. The rational use of different biological agents or compost can not only affect the bacterial structure of the plant roots, but also increase the number of beneficial bacteria in the roots. The sclerotia of cotton Verticillium wilt persists in the soil for a long time and spreads as soon as the environmental conditions are ripe.

Through the application of organic fertilizer, the soil quality is improved, and the land is essentially improved, so as to achieve the purpose of controlling soil fertility. Certain studies have shown that when the land becomes fertile, it will be difficult for germs to invade, which is also a means to solve the problem from the root.

Proper pruning can improve the nutritional status of cotton and the microclimate of cotton fields, thus affecting the occurrence of Verticillium wilt. Effective experiments showed that removing 4-5 buds from 1-2 fruit branches in early summer could significantly reduce the occurrence of cotton Verticillium wilt and reduce the disease index. Cutting off the ineffective buds and ineffective branches of cotton plants and increasing the spacing between branches and leaves can improve the ventilation conditions of cotton fields and reduce the accumulation of Verticillium wilt pathogens.

Question: chlorobromide, isocyanuric acid, and allicin, which sterilization effect is good.

The incidence of Verticillium wilt in dry irrigation is about 50% lower than that in flood irrigation. At the same time, drainage should be carried out in time after rain and flood. Avoid a sudden decrease in osmotic pressure, which will affect the respiration of cotton roots.

Rather than wet is one of the basic rules of cotton planting.

Chlorobromoisocyanuric acid is a little better.

Answer]: Cotton Verticillium wilt symptoms: It is easy to be infected at the seedling stage and the early stage of planting.

At the beginning of the disease, the leaf edges and leaf veins first turn yellow, and gradually progress to the yellowing of half or the whole leaf leaves. The weather is dry, dry or sunny, and the cotton seedlings wilt around noon, and return to normal in the morning and evening. In the later stage, it turns from yellow to brown, sometimes the leaf edge is curled upward, wilted or falls off, and in severe cases, the leaves of the diseased plant are lost and the leaves are left, leaving only the stalks.

Fusarium wilt is a bacterial disease that occurs suddenly on a large scale, and it is generally determined that yellow wilt is viral, which begins with only a few plants, and is usually transmitted by stinging insects before gradually and rapidly infecting. What can't be treated with antibacterial spray is usually a virus. Information in WeChat.

Cotton wilt and Verticillium wilt are systemic vascular diseases that cause leaf death or shedding, and are common diseases in the cotton growing season. The prevention and control methods are basically the same, mainly prevention and control, and according to the incidence of the disease in different cotton areas, different methods are adopted according to local conditions.

Clause.

1. Agricultural control

1.Breeding resistant species is now a useful method. In cotton production, disease-resistant varieties are used to improve plant resistance and control disease.

2.Strengthened quarantine. It is strictly forbidden to transfer cottonseed, cottonseed cake and cottonseed husk from the epidemic area.

3.Diseased plants should be uprooted and soil disinfection should be carried out in lightly diseased fields; In the south, water and drought crops can be rotated for two to three years, and in the north, wheat and corn and other cereal crops can be rotated for three to four years.

4.Improve the control work before the current germination. The cotton bud stage is the critical period for the occurrence and development of cotton wilt and verticillium wilt, and some affected cotton fields spray nutrients such as potassium dihydrogen phosphate and fulvic acid before the cotton plants show symptoms to improve the resistance of cotton plants and reduce the incidence of disease.

5.Strengthen on-site management. diligent and deep cultivation to increase ground temperature and reduce soil moisture; ditching and draining water to lower the water table; Increase the application of decomposed organic fertilizer and phosphorus and potassium fertilizer to prevent the partial application of nitrogen fertilizer.

Clause.

2. Chemical control

2.When sporadic diseased plants are found in the field, they should be immediately uprooted, collected, incinerate, and disinfected in and around the lesions.

3.Root irrigation and spraying: A combination of spraying and root irrigation can be used for heavy plots.

Root irrigation, with fifty to one hundred milliliters of liquid per plant, can reduce damage and control the spread of disease. For plots that have not been diseased, foliar fertilizers such as fulvic acid or potassium dihydrogen phosphate should be sprayed to improve the resistance of cotton plants and reduce diseases.

The best way to prevent diseases is to prevent diseases before they occur, that is, we advocate the majority of farmers to strengthen field inspections, find scattered diseased cotton fields, uproot diseased plants in time and burn them, and disinfect the soil at the diseased plants.

You can choose some pesticides to spray on the seedlings of cotton, or you can turn the soil frequently, water more, and pull out the cotton that has blight and verticillium wilt.

Pesticides. Because pesticides can well prevent and ** cotton wilt and verticillium wilt, pesticides should be used.

Go buy some pesticides that specialize in this disease, so that you can ** two diseases, these two diseases will reduce the yield of cotton.

Find the cause of the disease, buy some ** medicine for this disease, spray the medicine on the cotton, so that you can**.

Cotton wilt and verticillium wilt are mainly spread and spread through infected cottonseeds, cottonseed cakes, cottonseed husks, diseased plant residues, soil, fertilizers, flowing water and agricultural field management tools The application of organic fertilizer can reduce the leaching phenomenon and block the spread of cotton wilt and Verticillium wilt in the soil to a certain extent Therefore, cotton wilt verticillium wilt is a serious infectious disease, but it is not an infectious disease

So the answer is:

Cotton wilt and verticillium wilt are mainly spread and spread through infected cottonseeds, cottonseed cakes, cottonseed husks, diseased plant residues, soil, fertilizers, flowing water and agricultural field management tools The application of organic fertilizer can reduce the leaching phenomenon and block the spread of cotton wilt and Verticillium wilt in the soil to a certain extent Therefore, cotton wilt verticillium wilt is a serious infectious disease, but it is not an infectious disease

So the answer is: