When is the best time to spray herbicides?

In the process of weed control, it is crucial to correctly grasp the timing of herbicide spraying, which is directly related to the weed control effect and crop safety. So when is the best time to spray herbicides? Let’s learn more about it below.

When is the best time to spray herbicides?

The best time to spray herbicides is usually before 10 a.m. or after 4 p.m. on sunny days, and throughout the day on cloudy days (not raining). During this period, the temperature is moderate and the humidity is high, which is conducive to the adhesion and absorption of herbicides. However, the specific spraying time should also depend on factors such as the specific herbicide type, crop type, weed growth stage and environmental conditions.

What factors affect the timing of herbicide spraying?

1. Temperature

Temperature has a significant effect on the effectiveness of herbicides. High temperature is conducive to the absorption of herbicides by weeds, but too high temperature will cause the liquid to evaporate too quickly, affecting the efficacy of the drug. Therefore, the optimal temperature for application is usually between 10℃ and 24℃.

2. Humidity

Air humidity is also important for herbicide absorption. Appropriate humidity can help herbicides adhere better to weed leaves, thereby improving their effectiveness. Generally, the best results are achieved when there is no dew on the leaves and the air humidity is high.

3. Soil moisture

Soil drought reduces the effectiveness of herbicides because crop and weed growth slows, affecting the absorption of the drug. In drought conditions, application rates may need to be increased to compensate.

4. Rainfall

Rainfall immediately after application will cause the liquid to be washed away, reducing its efficacy. Therefore, avoid applying on days when rain is expected.

5. Lighting

Some herbicides require light to work, while others may break down in the light, so the application time should be determined based on the characteristics of the specific herbicide.

6. Soil pH

Soil pH affects the stability and effectiveness of herbicides. Most herbicides work best in neutral soils (pH 5.5-7.5).

7. Growth stages of crops

Different crops have different sensitivities to herbicides at different stages of their growth, and the application time should be adjusted according to the specific conditions of the crops.

8. Weed growth

The size and growth rate of weeds will also affect the effectiveness of herbicides. Pesticides should be applied during the weed growth period to achieve the best control effect.

In general, when using herbicides, in addition to considering the usage and dosage, the timing also needs to take into account a variety of factors to ensure safety and effectiveness and reduce the impact on the environment and non-target crops.