What are the diseases of cotton? How can I prevent it?

1. Cotton wilt, cotton wilt is the most common and main disease of cotton, it occurs all over the world, has serious harm to cotton production, and causes large losses. Cotton wilt disease mainly harms cotton seedlings, there are many forms at the onset of the disease, some leaves appear yellow reticulation, and finally the leaves wilt, some leaves turn yellow or purple, but eventually the leaves wilt and the plant dies. Prevention and control methods:

Fusarium wilt can safely overwinter in soil and fertilizer, and as it continues to spread new plants in the coming year, seeds, soil, fertilizers, etc. should be disinfected and sterilized before planting. Reasonable dense planting, fertilization, dilution with carbendazim in the early stage of the disease can be used to irrigate the roots or spray. 2. Cotton Verticillium wilt, cotton Verticillium wilt and wilt are only one word apart, from the name we can get, cotton Verticillium wilt onset when the leaves lose water, and the leaves appear yellowish patches, with the spread of the disease, the spots gradually expand.

After a long period of dry rainstorms, the leaves suddenly wilt and then fall off. Prevention and control methods: choose varieties with strong disease resistance, avoid continuous do, it is best to rotate with other crops, can reduce the occurrence of diseases, spray growth regulators such as shrinkage and safety in the budding stage, and regularly spray mancozeb or methyl sulfide and other agents, which have a preventive effect.

Cotton wilt and Verticillium wilt: both are diseases that damage the vascular tissues of cotton, causing symptoms such as discoloration, dryness, shedding and wilting of cotton leaves, and in severe cases, they die in succession, seriously affecting the yield. More potassium fertilizer can be applied at the cotton bud stage, or Bacillus subtilis can be applied dropwise.

Cotton has wilt, in the process of growth, but also breed aphids, cotton blind bugs are the insects that appear in the middle of cotton growth, this reset is due to the rainy season when the weather is wet, it will multiply in large numbers, to choose high-quality insect-resistant varieties, timely pest control.

What are the symptoms of cotton blight? What can farmers do to prevent it? For cotton farmers, understanding these issues can better cope with cotton blight. The following content will lead you to understand the relevant technical knowledge, I hope it can be helpful to farmers.

Symptoms: When the seedlings are harmed, reddish-brown striped lesions appear at the root and stem base, and then the lesions surround the stem, resulting in necrosis at the base of the stem, and when the leaves are harmed, they generally start from the leaf edge, and the dark green water-soaked spots appear at the beginning, and then gradually expand into dark green irregular water-soaked lesions. It turns black and dies at low temperature and high humidity; When drying, the cotyledons fall off.

When it is harmful to cotton bolls, it is mainly to damage the cotton bolls of the lower fruit branches. It mostly occurs from the boll surface, boll seam and bell tip under the cotton boll bract, and the light brown, light blue to black water-soaked lesions appear in the early stage, and the whole cotton boll becomes shiny blue-green to black-brown in the later stage, and when the climate is humid, a thin layer of white mold appears on the surface of the cotton boll.

Occurrence rule: rainy at the boll stage, vigorous growth, dense fruit branches, easy to disease. Cotton bolls on the lower fruit branches and cotton bolls with a boll age of 30-50 days are the most susceptible to the disease.

The terrain is low-lying, the soil is clayey and heavy, the cotton field is damp and closed, the cotton plant has many wounds, the fruit branch node position is low, and the nitrogen fertilizer is applied in the later stage, and the disease is serious. Defeat is big.

Control measures: 1. Crop rotation with other crops. noisy and rational application of nitrogen fertilizer.

Remove empty branches, wipe off redundant buds, and beat old leaves in time; In the future, drain the water in time, plant it reasonably densely, and remove the rotten diseased bells. Reduce the damage caused by agricultural operations to cotton seedlings and cotton bolls, treat insects and prevent diseases in time, and reduce the chance of germs from the wound.

In the first half of the month, the cotton boll stage, that is, the initial stage of the disease, is the key period for the prevention and control of cotton blight.

Cotton boll stage, pay attention to pesticide prevention, can be sprayed with the following agents:

75 chlorothalonil wettable powder 600-8000 times;

70. Prevention of manganese-zinc wettable powder 600-800 times and other chemicals.

At the beginning of the onset of the cotton boll stage, spray the following agents in time:

58 Methalamine mancozeb wettable powder 700 times liquid;

64 Frost Spirit-Mancozeb WP 600 times;

72 700 times of frost urea cyanide mancozeb wettable powder;

69 Enoylmorpholine mancozeb wettable powder 900-1000 times, once every 10 days or so, spray 2-3 times depending on the condition.

Cotton can be said to be an important export crop in our country, of course, we are inseparable from cotton in our daily life.

For example, the clothes we wear every day, the quilt that we have to cover every day to sleep are all made of cotton, and the cotton we see is white, but this is after a lot of processing procedures before it becomes like this, and the process of planting and cultivating cotton is also very difficult, from the beginning of planting, it needs to be watered regularly and weeds are treated. <>

In addition, the most important point is the prevention of pests and diseases, cotton is easy to get pests and diseases, once you get this disease, it will reduce the quality of cotton.

The things that lead to it are not so comfortable, so we should be clear when planting cotton which kinds of pests and diseases and common pests and diseases cotton may have, and how to prevent and control it, blight is the most common pest and disease, and the most serious impact on cotton, but when it occurs, we can observe it in time, and give specific treatment measures, another disease is Verticillium wilt. <>

As the name suggests, it refers to the appearance of yellow spots on the leaves.

Although it is not as severe as blight, but if it is not managed, the disease will only spread more and more, and eventually lead to the death of cotton, or the cotton is very poor, the insect pests mainly belong to cotton aphids and cotton bollworms are the most prominent, if you get cotton aphids, then cotton aphids will absorb the nutrients of seedling leaves, resulting in leaves can not develop well. <>

The fruit will affect the time of cotton flowering and the amount of cotton seeding, and the cotton bollworm is even more severe, it will eat some cotton buds, resulting in cotton not being able to flower. Therefore, when planting cotton, it is not okay to plant it, but it is still necessary to manage it diligently, maintain it, pay attention to pests and diseases, take appropriate methods of planting, and prevention and control are very important means, if you want cotton to grow well, you must spend corresponding energy.

The most common diseases are black root disease, rotten root disease, blight, black spot, etc., these are the most common diseases, and will affect the yield of cotton, and these pests and diseases are very serious.

Cotton soft auxiliary diseases, cotton leaf burning, cotton ring disease are all common diseases of cotton, for the influence of weather and temperature, too many pests, cotton is prone to these diseases.

The common diseases of cultivated cotton mainly include root rot, black root disease, wilt, black rot, virus disease, and stem blight, which are relatively common diseases, and should be dealt with in time once found, otherwise it will affect cotton yield.

Fusarium wilt is the most common pest and disease, and the most serious impact on cotton, but when it occurs, we can observe it in time and give specific treatment measures, and the other disease is Verticillium wilt.

Standing blight, anthracnose, red rot, cataplexy, root rot, cotton red leaf stem blight, cotton blind bugs, etc.

Introduction: Cotton is an essential part of life. It not only plays an important role in daily wear, but also gradually spreads in the application of decorations.

Good clothing requires high-quality cotton, and if you choose low-quality cotton, it will lead to a shorter shelf life of the product, and at the same time, it will also bring inconvenience to consumers. Therefore, it is necessary to pay attention to the planting of cotton, so what diseases need to be paid attention to in the later stage of cotton? There are the following observations.

It is not difficult to find that farmers who have planted cotton have a correspondingly deep understanding of the study of cotton diseases, and neutral blight is a prominent disease of cotton, which mainly comes from the soil. At the same time, the seeds of lotus flowers will also have a certain strain, and the strains can infect each other. It can infest cotton seedlings, and the roots can cause root rot, which is often the most susceptible to infection during the growth period of cotton.

If the soil temperature of cotton cannot be guaranteed, a large number of cotton seedlings will die. <>

Cataplexy can cause cataplexy during the planting of cotton, and it is necessary to control the same humidity and try to avoid planting in the rainy season. At the same time, we should ensure that the humidity of the planting land and the improvement of field drainage should be ensured, and the appropriate amount of pesticides can prevent cotton diseases, and spraying pesticides during the growth of cotton can effectively prevent cotton cataplexy. When the cotton seedlings have just budded, if they are infected with cataplexy at this time, it will often lead to rot and darkening when the overgrowth is severe.

As the seedlings gradually wither in the later stage, if such a situation occurs in cotton, it is often a blow to agriculture.

It can cause anthracnose in the seedling stage of cotton, and if light rain continues, it will cause anthracnose in cotton. Its roots are also in the same condition as those described above, and they will not only rot but also develop lesions, which are reddish-brown at the edges of the lesions. At the same time, there will also be cracks in the middle, which will cause the breakage and fall of cotton cotyledons, and will also directly lead to the withering of seedlings and affect the yield of cotton.

Fusarium wilt, Verticillium wilt, prevention of diseases and insects These are all things that need to be paid attention to, because there will be some particularly many diseases in the later stage of cotton, so in the later stage of cotton, we must pay attention to protection, and some pesticides can be used in advance to prevent some pests and diseases.

Technical points of post-cotton management, foliar spraying of chemical fertilizers to prevent premature senescence, post-management of cotton should focus on preventing premature senescence, and foliar spraying of fertilizers to meet the nutritional needs of cotton. Foliar sprays should be preceded by multiple sprays of a multi-fertilizer mixture consisting of urea, potassium dihydrogen phosphate, zinc sulphate and boric acid. After spraying 1% 2% diammonium hydrogen phosphate solution or potassium dihydrogen phosphate solution in stages, spray 50 kg of fertilizer solution per mu each time, with an interval of 7 10 days, to achieve the purpose of preventing premature aging and promoting precocious maturity.

If you split the stem of the diseased plant, you can see the brown streaks to confirm that it is blight. Fusarium wilt is an important soil-borne disease that can survive in the soil for up to more than 10 years. Wounds in the roots are the main point of entry for the germs.

The invasion of bacteria multiplies in vascular bundles, blocking the rise of water and causing the plant to wilt and die. The germ can also survive in the cotton seed for more than ten months.

If the disease has already occurred, emergency measures should be taken to prevent the spread of the disease and the aggravation of the disease. The method is to choose one of the following pesticides for root watering: 50% carbendazim 1000 times, 2000 times, 75% dixone 1000 times, 100-200 ml per plant, then every other week, 3 times.

The fundamental method for preventing and controlling Fusarium wilt is to implement plant quarantine and resolutely not to introduce diseased cotton seeds from other places. In areas where cotton wilt has occurred, the cotton seeds used should be treated with sulfuric acid (one kilogram of crude sulfuric acid can be mixed with about 10 kilograms of cotton seeds), and the depilated cotton seeds need to be cleaned and used or dried for later use. Diseased cotton fields can be replanted with 1-2 ripe rice to basically kill pathogens.

When sporadic diseased plants appear, they should be uprooted and burned in time, and the diseased soil should be watered with 135 grams of 50% cotton and 45 kg of water, or irrigated with 200 times of Si Meidi (Wei Baimiao).

If the land has developed wilt this year, cotton can no longer be planted next year, and it is better to plant one-crop rice instead.

Cotton is a very important cash crop in China, so how to diagnose and prevent cotton wilt? Let's take a look at the details I will explain in detail.

First, the symptoms of cotton wilt.

1) There are three types of symptoms of Fusarium wilt at seedling stage, one is the yellow reticulation type: the veins of the diseased plant turn yellow, the mesophyll remains green, some or most of the leaves are yellow reticulated, and the leaves gradually wither and wither. The second type is yellowing or purplish-red:

The margins of the leaves turn partially or mostly yellow and gradually wither; Most or part of the leaves are purplish-red, and the veins are also purple-red, gradually wilting and wilting. The third type is wilting: the leaves suddenly lose moisture, the leaf color becomes dark green, the leaves become softer and thinner, the whole plant wilts and dies, but the leaves generally do not fall off, and the petioles are curved.

2) Symptoms of Fusarium wilt in adult plants at the seedling stage also occur in the adult stage, but the common symptom of adulthood is dwarf: when there are 5 to 7 true leaves, the top leaves of the plant are shriveled, deformed and dark in color. Green, with short internodes, shorter than healthy plants, yellow reticulate or yellow spots on the middle and lower leaves, generally not dead.

The second type is acute wilting: when the heavy rains turn clear in summer, all the leaves of the diseased plant lose water and wilt. The third type is the top withering type

It mostly occurs in the late stage of cotton growth, and the diseased plants gradually wither from top to bottom, and a large number of leaves and bolls fall off.

Second, the causes of cotton wilt disease.

Cotton's own disease resistanceCotton resistance to wilt is caused by physical hindrance and chemical antimicrobial action. Antimicrobial substances are mainly phytoalexin, namely mushroom-like aldehydes and some enzymes, such as a-aldehyde, the main components of which are gossypol and its derivatives. Resistance of upland cotton to Fusarium wilt is controlled by dominant genes.

A parent is resistant to blight, and its offspring are also resistant.

Third, the prevention and control of cotton wilt.

1) It is strictly forbidden to transfer seeds from disease-free areas to protect disease-free areas, and seeds from self-selected and self-fertile disease-free areas must be sterilized. That is, after the cottonseed was dehaired with sulfuric acid, the antibacterial agent "402" solution was soaked at 55 60 h or 50% carbendazim at room temperature for 14 h, dried and sown. (2) Eliminate sporadic disease areasWhere the incidence rate of Fusarium wilt plants is less than that of sporadic disease areas, sporadic disease plants should be removed and destroyed, and the soil around the diseased plants should be treated.

That is, after the diseased plant is found, the diseased plant and the surrounding diseased plant carcass are first picked up, and then the soil within 1m around the diseased plant is loosened and disinfected.