Beware of the three major drug hazards of cotton

Diagnosis and identification of insecticidal and fungicides. The damage degree of insecticides and fungicides is not only related to cotton variety, development stage and morphological characteristics, but also different from each other. For example, if dichlorvos is highly vaporized, the cotton leaves can be smoked by spraying with 1000 times liquid twice; after being damaged by stone-sulfur mixture, the leaves and boll shells of cotton plants will produce burn patches, and the leaves will soon dry up and fall off. Stone-sulfur mixture is a strongly alkaline medicament. Bordeaux solution can only be used 7 ~ 10 days after use. If stone-sulfur mixture is sprayed within 1 ~ 2 months after spraying Bordeaux liquid, the leaves of cotton plants will produce black copper sulfide precipitates, causing drug damage. In short, when using cotton insecticides and fungicides, there should be a certain interval between the continuous use of several pesticides (especially inorganic pesticides) to prevent drug damage caused by the reaction of different pharmacological agents. In addition, the degree of cotton drug damage is also affected by the environment, such as spraying at high temperature, due to high temperature water evaporation, the concentration of the agent will increase, so that cotton leaves appear spots, yellowing, curling, until scorched death.

Diagnosis and identification of herbicides. There are more than 30 kinds of common weeds in cotton field. In cotton production, improper use of herbicides often leads to drug damage, and the symptoms of drug damage are often variable and diverse, including growth inhibition, bending, twisting and curling of stems and leaves, shortening of internodes, leaf thickening, chlorosis, albinism, withered spots and deformities. If diuron is absorbed by cotton, it is difficult to transmit upward, and if used in the presence of two true leaves of cotton, the damage rate of cotton will reach more than 90%. After the damage, it will make the tender leaves of cotton fade, lose green and wither. After being damaged by trifluralin, it can cause the second and third true leaves of cotton plant to shrink and become smaller, and if the drug damage is serious, it will also cause cotton cotyledons dark green, thickening and brittleness, thickening of stem base, plant becoming shorter, and even cause growth point necrosis and lateral branches clustered. In addition, cotton is very sensitive to 2mem4murD. In production, the sprayer that has been used is often used in cotton field spraying (or drifting to neighboring cotton fields when spraying other crops with 2pyr4murD). The injured cotton plants are characterized by smaller leaves, narrowing, twisted vein stalks, wrinkles and deformities, often in the shape of chicken claws.

Diagnosis and identification of drug damage caused by plant growth regulators. If plant growth regulators are not used properly, they will often cause man-made drug damage to cotton plants. For example, dwarftin is a kind of trace and efficient, which can inhibit crop cell growth (but not cell division). At a suitable temperature, it can effectively control plant vegetative growth and promote reproductive growth. However, cotton is more sensitive to clenbuterol, such as excessive concentration and excessive dosage, it will inhibit the growth of cotton, make the cotton plant too short, poor ventilation and light transmission, bud and boll easy to fall off, cotton bolls become deformed and so on.