Cotton injury

Symptoms Cotton suffers more from pests and diseases during its entire growth and development. Frequent use of drugs in production, will inevitably produce phytotoxicity. All pesticides have adverse consequences on the growth and development of crops and are called phytotoxicity. Such as the application of dichlorvos, dimethoate, herbicide ether and other improper, easy to trigger contact with the type of injury. Such as dichlorvos injury, leaf first purple, after changing to bright red or light yellow, veins remain green, veins also turn yellow; Bordeaux liquid phytotoxicity, leaves produce varying sizes of coke spots, hardening, early fall, plant shrinkage Lithosulfur compound harms the leaves and the shells produce burns, and the leaves are easy to dry off. Application of herbicides such as 2,4-D, dimethyltetrachloro-, 2,4,5-anthraquinone often produces systemic types of phytotoxicity, also known as chronic phytotoxicity. , deformity, thickening of the leaf, thick green leaves, leaf shrinkage, etc. Severe lateral branches, growth point necrosis. When the cotton was damaged by 2,4-D, the leaves were chicken-like and the leaves became smaller and narrower. Excessive damage caused by trifluralin causes the cotton roots to form tumors. The excessive concentration of chlormeine can also produce similar symptoms. Flowering drugs often affect pollination, resulting in ovary infertility or produce falling flowers, buds.

Causes of pesticides, fungicides, herbicides, plant growth stimulating hormones and other types of pesticides are inappropriate, or the application of high concentrations, spraying the wrong time, flowering or use of cotton sensitive herbicides can produce phytotoxicity.

Control methods (1) Select pesticides, and achieve the right medicine. (2) determine the appropriate concentration, strictly in accordance with operating procedures, do not apply at flowering time. (3) When applying herbicides in cotton fields, pay attention to soil organic matter content, sandy soil with low organic matter content, and the dosage should be less, otherwise, the dosage can be increased. When herbicides are sprayed, separate barriers should be set up to pay attention to the wind direction and prevent the wind from drifting and injuring nearby sensitive crops.
Necessary sprayer for exclusive use. (4) After the occurrence of phytotoxicity, the quick-seeking fertilizer is chased. After applying herbicides to produce phytotoxicity, quick-acting fertilizers can be applied or remediation can be carried out using extra-root fertilizers. The phytotoxicity of hormonal herbicides such as 2,4-D and dimethyl tetrachlorine after they are transported to the cotton field can be used to destroy the deformed branches, spraying gibberellin or ash and activated carbon as necessary. Strong adsorption of activated carbon can reduce pesticide contamination of soil. (5) spray water spray If the spray herbicide or insecticide excessive or adjacent to sensitive crops suffer from phytotoxicity, you can open the sprinkler device or use a sprayer, continuous spray 2-3 times clean water, you can remove or reduce the amount of pesticide residues on the leaves; For those pesticides that are susceptible to decomposition by alkaline substances, 0.2% sodium carbonate should also be added to the water for rinsing and neutralization. (6) A sufficient amount of water to make a large amount of water absorption in the root system, reduce the relative concentration of harmful substances in the cotton plant, has a certain degree of mitigation. If the application of soil over-dosage, the use of irrigation can also rule out some of the drugs, reducing the damage. Combined with top-dressing cultivating tillage soil, increase soil permeability and ground temperature, promote root development, and enhance plant resilience. (7) Advocate the spraying of green wind 95, the second generation of high beauty and beauty of the United States - Jin Bilai, Plant Power 2003, etc., so that the affected cotton can quickly return to normal.