The pesticide control methods for common cotton diseases are as follows:
First, the blight of cotton blight is commonly known as rotten root disease and black root disease. It occurs in all cotton areas of the country. After the cotton seedlings are damaged, yellow-brown lesions are produced at the base of the stem near the ground, and then become dark brown. Gradually sag and rot, when the disease is thin, the diseased seedlings die or fall. After the cotyledons are damaged, irregular yellow-brown lesions are formed, and the diseased part is broken and punctured into a perforated shape. After the adult stage is damaged, brown spots appear on the leaves, and then the perforations are shed.
Control methods: 1, reasonable rotation: and grass crops: rotation for 2 to 3 years. 2, reasonable fertilization: fine land preparation, increase the application of decomposed organic fertilizer or 5406 bacterial fertilizer. 3, improve the quality of sowing: spring cotton with a depth of 5 cm deep 14 ° C is suitable for sowing date, generally planting 4 ~ 5 cm deep is appropriate. 4, strengthen seedling management: appropriate morning seedlings, diligent ploughing, reduce soil moisture, increase the upper temperature, cultivate strong seedlings. 5, the seed dressing seed selection, with seed weight 0.5 to 0.8% of 50% carbendazim, or seed weight 0.6% of 50% methyl thiophanate, seed dressing.
Second, Fusarium Wilt is also called plant cancer, is the enemy of cotton production, in recent years, spread rapidly. The characteristics of blight are: the plant is dwarfed, the leaf color is grayish green, brittle and hard, the stem is curved, the stem is shortened, the top core is sunken, and the vascular bundle in the stem becomes taupe or light black. Incidence conditions: high temperature and high humidity, even planting, sunny after the rain, will go into a row, die.
Control methods: 1. Soil modification: On the basis of the application of organic fertilizer, nitrogen, phosphorus and potassium, 0.5 kg of heavy sputum per acre can be added, and then ploughed, which can kill most of the soil bacteria and make it in the soil. Increase gas permeability, eliminate the content of pin citrate in the soil, break the knot, improve the saline and alkali, enhance the disease resistance of the plant, and reduce the damage of the blight. 2. Apply appropriate amount of nitrogen fertilizer. 3, watering at the right time, the average cotton plant has two bells when the weather is dry, the first water is poured, the early watering will promote the disease; 4, the seedling, bud and flowering and bolling period regularly spray 2-4 times of yellow first aid, Or dysentery to prevent blight. 5, for the diseased plants can be operated and controlled, it is set to 5 to 6 cm on the stem of the cotton base with a knife to open a 2 to 3 cm longitudinal mouth, insert two sections of the matchstick soaked with the yellow yellow emergency solution for more than 4 hours, take The above method can effectively control the damage of cotton wilt, and can also control the wilt of other crops.
Black rot black rot cotton roots are black, slightly convex, no new roots grow, plants are short, leaves are soft, slow growth, easy to die under high temperature, the plants are black and dead after death, erect not Down, the affected area is massive. After the rain, the water accumulated for a long time, the terrain is low, the saline-alkali is heavy or the amount of nitrogen fertilizer is large, and the cultivating is not timely. The sweet potato, sugar beet, Chinese cabbage, cabbage, and radish plots are easy to develop.
Control methods: 1. Level the land, prevent water accumulation, and drain in time. 2. Temporary cultivating of loose soil after rain, improve root activity. 3, the application of lime powder 15 kg per acre, ferrous sulfate 10 kg or the application of heavy bismuth, fertilization can reduce and control the occurrence of this disease. 4, increase the application of organic fertilizer and phosphorus and potassium fertilizer, control and appropriate amount of nitrogen fertilizer; 5, the use of dry yellow first aid in the onset, rotten speed Kang 20 grams each, add water 15 kg, spray leaf surface or root irrigation can effectively prevent black rot.
4. Viral diseases Cotton virus diseases mainly include lobular virus disease, mosaic virus disease, smut disease, purple leaf virus disease deciduous, falling flower, fruit drop virus disease, virus disease is called plant AIDS, spread quickly, serious damage, Reduced production invisible, is the plant's first enemy.
Control method: In the early stage of cotton growth, the virus doctor, anti-toxin, virus, and disease can be prevented.
5. Stem blight Cotton can be damaged from seedling to bolling stage. In the early stage, it is harmful to cotyledons, true leaves, stems and growth points, causing rotten seeds, leaf spots, stems, broken leaves and even dead plants, and later infection. The leaves and blue bells cause leaves and deadlocks. The cotyledons and true leaves are initially yellow-brown small round spots with purple-red edges, which are then enlarged into nearly round or irregular brown spots, and many small black spots (pathogenic bacteria) are scattered on the surface. The stem and petiole are damaged, initially reddish-brown dots, and then expanded into dark brown fusiform ulcerated spots, with central depression and purple red around. When the condition is serious, the diseased part is broken and the stems are dead.
Control methods: 1, reasonable rotation, reasonable close planting, improve ventilation and light transmission conditions. 2, seed dressing, cottonseed sulfuric acid after depilation, mixed with carotenol and carbendazim ratio of 1:0.5 seed coating agent, both disease prevention and treatment of aphids. 3, spray, seedling stage or adult stage onset, can be controlled by 65% ​​dasen zinc 800 times solution, or 70% methyl thiophanate 1000 times solution spray.
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