What is the lowest temperature that should be paid attention to when using herbicides in wheat fields?

The minimum temperature of application in wheat field is 2℃, and it shall not be lower than this temperature before application and two days after application.

1, drugs are prohibited in windy days. Herbicide is easy to use in windy days, and the effect is not good. It may also blow to greenhouse crops or other crops and cause herbicide damage, so it is necessary to pay attention to prohibiting the use of herbicides in windy days.

2. It is forbidden to use drugs in bad weather. It is forbidden to use herbicides in bad weather such as frost, rain and snow, hail and cold current, and attention should be paid to avoiding such bad weather before and after using herbicides. Farmers must pay attention to the weather forecast.

3. Don't use herbicides when the wheat seedlings are weak and the roots are bare. Generally, the straw in winter wheat field is returned to the field, and the plot is relatively loose. If the weather is abnormal, such as warm winter and drought, we must pay attention to the fact that the root system of wheat may not be deeply rooted because of loose soil, or some roots may be exposed. This kind of wheat is easy to cause frostbite and water shortage, and this kind of wheat seedling is the most sensitive and fragile. If herbicides are applied at this time, it is easy to cause some damage to wheat.

4. Don't use herbicides when wheat is sick. In recent years, seed-borne or soil-borne diseases such as wheat sheath blight, root rot and take-all disease have occurred frequently. Before using herbicides, farmers should determine whether their wheat seedlings are sick. If it is sick wheat, it is best not to use herbicides. It is suggested that farmers should pay attention to dressing seeds with special chemicals before sowing wheat to prevent diseases.

Extended data:

1. Herbicide refers to a kind of chemical that can completely or selectively kill weeds, also known as herbicide, which is used to eliminate or inhibit plant growth.

2. Commonly used varieties are organic compounds, which can be widely used to control weeds, miscellaneous irrigation, miscellaneous trees and other harmful plants in farmland, orchards, flower nurseries, grasslands and non-arable land, railway lines, rivers, reservoirs, warehouses and other places.

3. Strictly control the sensitivity of crops to herbicides. Different crops have different sensitivities to herbicides. If the pesticides are not selected according to the sensitivity of crops to herbicides, even if herbicides that are safe for crops are used, sometimes it is easy to cause phytotoxicity. General herbicides for controlling broadleaf weeds are sensitive to dicotyledonous crops, while herbicides for controlling gramineous weeds are sensitive to gramineous crops.

4. Strictly control the sensitive period and application period of crops. Crops have different sensitivities to pesticides and fungicides at different growth and development stages, and even to herbicides.

5. Strictly control the dosage and concentration of herbicides. The selectivity of herbicides is within a certain dosage range, so even selective herbicides will cause phytotoxicity to crops if they exceed the prescribed dosage range.

6. Strictly use herbicides. The application methods of herbicides include stem and leaf treatment, soil treatment and weed control and film removal.

References:

Baidu encyclopedia _ herbicide