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What are the causes of cotton diseases
Poor-quality seeds, low temperatures with high humidity, and careless sowing are factors in the occurrence of cotton diseases. 1. Climatic conditions. Various pathogens of cotton diseases multiply rapidly under high-humidity conditions, while low temperatures are unfavorable to the growth and development of cotton's young roots. In some early-sown cotton fields, under conditions of spring cold and overcast rain, the young roots grow slowly while pathogen infection is frequent, easily causing seed rot and sprout rot. 2. Seed quality. Seeds with low maturity, or that have absorbed moisture and become moldy, are prone to seed rot and sprout rot; this not only hinders emergence, but most seedlings after emergence are also weak and prone to
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Cotton disease control: grasp the key at the seedling stage
The main cotton seedling diseases include damping-off, anthracnose, black spot, seedling blight, and root rot. The main cause of cotton seedling disease is seed-borne and soil-borne pathogens; once suitable climatic and environmental conditions for disease development occur, cotton seedling diseases will break out severely, harming the normal growth of cotton seedlings, with the disease incidence in ordinary years being 30%-50%. In recent years, with the promotion of transgenic insect-resistant cotton, cotton seedling diseases have shown a trend of gradually worsening, directly threatening full stands from a single sowing and the early development of strong seedlings. Therefore, integrated control of cotton seedling diseases has become
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How to prevent cotton diseases? Mastering these techniques is key
In recent years, the harm caused by diseases has become one of the important factors restricting cotton yield and quality. For some diseases, the symptoms are not obvious at the beginning and are easily overlooked, and by the time they become severe, it is too late to take measures. Especially in continuous cropping plots, cotton farmers find some commonly occurring diseases and soil-borne diseases very troublesome, and often feel helpless. For this reason, when it comes to cotton diseases, the approach should be "prevention first, treatment second." There are quite a few cotton diseases, but the two that give cotton farmers the biggest headache are mainly these: first, the problem of dead seedlings caused by damping-off disease after emergence, and second, verticillium wilt and fusarium wilt. This
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Cotton shows disease symptoms, integrated control with multiple measures
Symptom identification of cotton Fusarium wilt and Verticillium wilt. Cotton Fusarium wilt can occur throughout the entire growth and development period of cotton, but it occurs more severely at the seedling stage. If favorable conditions occur, it can also break out heavily at the adult plant stage. Sudden wilt type: leaves suddenly lose water, droop and wilt, leaf color is dark green, leaves become soft and thin, the whole plant dries green and dies, but leaves generally do not fall off, and petioles bend. Yellowing type: can occur at both the seedling stage and the adult plant stage. The yellowing type mostly starts from the leaf margins, with part or all of the leaf turning yellow, and finally the leaf dies or falls off, while the petiole
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Detailed Explanation of Common Cotton Diseases and Their Control Techniques
I. Damping-off Cotton damping-off, commonly known as root rot and black root disease, occurs in all cotton regions nationwide. After cotton seedlings are affected, yellow-brown lesions appear at the base of the stem near the ground, then turn dark brown and gradually become sunken and rotten. In severe cases, the diseased part becomes thin, and the diseased seedlings wither and die or topple over. After the cotyledons are affected, irregular yellow-brown lesions form, and later the diseased part breaks and falls off, becoming perforated. After adult plants are affected, brown spots appear on the leaves, which later fall off and become perforated. Control methods: 1. Reasonable crop rotation: with gramineous crops: rotate for 2-
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Occurrence and Control Methods of Common Cotton Boll Diseases
Cotton boll disease is a composite disease caused by multiple pathogens, often manifesting as boll rot, which affects both cotton yield and cotton quality. Losses caused by boll rot reach more than 10% of total production. Common boll diseases in cotton fields in Henan Province include boll blight, anthracnose, red rot, pink rot, black boll, and others. They mostly occur in rainy years in mid to late August, and are especially severe during consecutive rainy days with high temperature and high humidity. I. Symptoms of Boll Diseases Boll blight: This disease mostly occurs on mature bolls in the lower part of the cotton plant, starting from the base, suture, or tip of the boll. It begins as a dark bluish-green water-soaked area, gradually spreading to the entire boll, turning bluish-brown, and finally becoming black, oily, irregular lesions with gradually lighter edges, and the boundary between diseased and healthy areas is not obvious.
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How to increase the yield of spring-planted shiitake mushrooms? Master these tips for high yields
Raise the temperature of the mushroom bed to create conditions for mushroom growth. Since the mushroom yard is still cold in early spring, natural air temperature can be used together with artificial regulation. The method is: cover the film tightly to increase the ground temperature, and at the same time choose sunny days to spread the shading materials on the shed surface thinly, letting sunlight penetrate into the mushroom yard, increasing the heat source and raising the mushroom bed temperature; at night, cover the film tightly to protect against the cold. The large day-night temperature difference in early spring can promote the occurrence of mushroom buds. Pat the mushroom logs to promote the recovery of mycelial growth. Because the climate is cold in early spring, the mycelium is mostly in a dormant state, producing no mushrooms or very few mushrooms. Generally, patting can be used
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What are the common physiological diseases of bag-cultivated shiitake mushrooms?
Physiological diseases, also known as non-infectious diseases, are poor growth phenomena caused by unsuitable growing conditions or the influence of harmful substances in the environment. Although such diseases have no pathogenic agents and are not mutually contagious, once they occur they can cause major losses. In Chunhua, Shaanxi, the most common physiological diseases of bag-cultivated shiitake mushrooms include mycelial thinning, mushroom burning (pile heating), yellow water in the mushroom logs, mushroom log decline, and deformed mushrooms. 1 Mycelial thinning 1.1 Symptoms: mycelial growth is sparse, and the mushroom logs are soft and lack elasticity. 1.2 Causes: ① The substrate had already become moldy before sterilization
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How to prevent and treat oleander black spot disease? Here are the methods
Symptoms The spots occur on the edges or middle of the leaves, semicircular or circular. When several spots join together, they form a wavy pattern, present on both the front and back sides, with the front darker than the back; the spots are grayish-white or grayish-brown; in the later stage, a black powdery mold layer develops on the spots, generally occurring on overwintering leaves. Pathogen The pathogen is a fungus, Alternaria sp. The conidia are olive-colored, oval, with both longitudinal and transverse septa, in chains, borne on relatively long conidiophores. Disease pattern Generally, old leaves, lower
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How to treat oleander leaf spot? Detailed methods for disease control in medicinal plants
Oleander, scientific name Nerium indicum Mill., is a woody plant of the family Apocynaceae. Its leaves and flowers are used as medicine; it is toxic. It has the effects of strengthening the heart and promoting diuresis, eliminating phlegm, and killing insects. It is distributed in most provinces and regions across the country. Symptoms mainly affect the leaves. At first, small purplish-red spots appear at the leaf tip or leaf margin, and after expanding they form circular, semicircular to irregular brown lesions. The lesions have concentric rings. In the later stage the center fades to white, and the red-brown margin is relatively wide. When humidity is high, a grayish-brown mold layer can grow on both sides of the lesions, namely the pathogen's conidiophores and conidia. The disease
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