When Is the Best Time to Spray Herbicide on Wheat? Master the Timing and Temperature

Abstract: You can choose to weed during the wheat seedling stage, in mid-to-late November, or during the wheat greening stage, from late February to early March. Generally, spray when the average temperature is above 6°C, and select the corresponding herbicide for control according to the weed species. At the same time, match the dosage reasonably; for example, in wheat fields where bromegrass is the main weed, you can use 70% flucarbazone-sodium water-dispersible granules at 3 grams per mu.

1. Timing of Weeding in Wheat

1. During the wheat seedling stage, in mid-to-late November, is the key period for weeding. At this time the weeds are relatively young and have relatively low resistance to the chemicals, so control is easier.

2. During the wheat greening stage, from late February to early March, is also a relatively good period for weeding, but at this time the weeds are older and more resistant to the chemicals. When controlling them, the dosage needs to be increased, but phytotoxicity is more likely to occur, so pay special attention to the dosage when applying.

2. Temperature for Spraying Wheat

1. When weeding wheat, observe the temperature and humidity. The average temperature should be above 6°C, and around 10 a.m. to 3 p.m. is relatively suitable. If the soil is relatively dry, increase the amount of water used. During this period, there must be no standing water, as it will affect the herbicide's efficacy and make it perform poorly.

2. Generally, spray the herbicide according to the recommended dosage. Do not arbitrarily increase or decrease the dosage, so as to ensure its efficacy and prevent phytotoxicity. When mixing several herbicides, use the two-step dilution method: first dilute the herbicide with a small amount of water to form a mother solution, then dissolve the mother solution into the specified amount of spray liquid before use.

3. The mixed chemicals should not be left standing for a long time and need to be used up in one go. Choose suitable weather for application, which can reduce the volatilization of the chemicals. Generally, it is not suitable to apply when the temperature is below 10°C. Later, maintain the application equipment well.

4. Before application, check the equipment in time to avoid spraying, dripping, and leaking during the application process. Apply evenly and take safety precautions. Smoking and eating and drinking are prohibited to avoid poisoning.

3. Suitable Chemicals and Formulas

1. Choose the corresponding herbicide according to the weed species. When there is only one species of weed in the wheat field, you can choose to use a single herbicide for control. When several weeds appear, such as a mix of monocotyledonous and dicotyledonous weeds, you can mix several herbicides in proportion for use, which helps broaden the weed-killing spectrum and thus improve the weeding effect. Several weeding formulas are provided below for reference.

2. In wheat fields where broadleaf weeds such as shepherd's purse, Japanese hop, Chorispora tenella, Lithospermum arvense, and lambsquarters are the main weeds, you can use 75% tribenuron-methyl water-dispersible granules at 1 g per mu, or 10% tribenuron-methyl wettable powder at 10 g per mu.

3. In wheat fields where Japanese bindweed is the main weed, you can use 20% fluroxypyr emulsifiable concentrate at 65 ml per mu.

4. In wheat fields where bromegrass is the main weed, you can use 70% flucarbazone-sodium water-dispersible granules at 3 g per mu.

5. In wheat fields where Beckmannia syzigachne is the main weed, you can use 10.8% fenoxaprop-P-ethyl emulsifiable concentrate at 35 ml per mu, or 15% clodinafop-propargyl wettable powder at 35 g per mu.

6. In wheat fields where bromegrass and broadleaf weeds grow together, use 70% flucarbazone-sodium water-dispersible granules at 3 g per mu, mixed with 10% tribenuron-methyl wettable powder at 10 g.

7. The above formulas require about 35 kg of water per mu, and are generally sprayed evenly with a hand-press sprayer or a spraying vehicle.