When is the best time to weed winter wheat? Save these 9 precautions

The planting area of winter wheat in our country is much wider than that of spring wheat, and its share of production is also very high. It is generally sown from mid-to-late September to early October, and matures from the end of May to late June of the following year. During the planting process, when is the best time to weed winter wheat? What are the precautions? Save these 9 points!

1. When is the best time to weed winter wheat

40 days after winter wheat is sown and watered is the safest time to apply herbicide. At this time, wheat is at the 4-leaf or 4-leaf-1-heart stage and has higher tolerance to herbicides. Moreover, at the 4-leaf stage of wheat, most weeds have already appeared, but their grass age is relatively young, and the wheat has not tillered and has few leaves, so it is easy to kill the weeds. At this time, herbicide is the most effective.

2. Precautions for weeding winter wheat

1. Strictly control temperature

Herbicide instructions generally state that it can be used at 2°C or at 5°C, but many people do not understand whether the 2°C and 5°C mentioned here refer to the temperature at the time of use or the minimum temperature.

The answer is actually the latter. The temperature here refers to the minimum temperature, which means it can only be used when the minimum temperature is above 2°C, and this temperature must not be lower than that for at least two days before and after herbicide application.

2. Do not use herbicide on windy days

Using herbicide on windy days can easily cause herbicide drift. If the effect of use is poor, it may also be blown by the wind onto other crops, causing herbicide damage to other crops. Therefore, attention must be paid to prohibiting the use of herbicides on windy days.

3. Do not use herbicide in severe weather

It is prohibited to use herbicides in severe weather such as frost, rain and snow, hail, and cold waves, and such severe weather must be avoided both before and after herbicide use. Farmer friends must pay attention to listening to the weather forecast.

4. Do not use herbicide when the field is loose

Generally, winter wheat fields undergo straw return, so the field is relatively loose. In years with a warm winter and relatively little precipitation, the wheat root system may be unable to take root because the soil is too loose, or part of the root system may be exposed above the surface. This can easily cause frost injury and water deficiency in wheat. If herbicide is used at this time, it is easy to cause damage to the fragile wheat.

5. Do not spray herbicide when disease appears

In recent years, seed-borne or soil-borne diseases such as wheat sheath blight, root rot, and take-all have occurred frequently. Before using herbicide, farmer friends should first determine whether their wheat seedlings have these diseases. If they do, it is best not to spray herbicide.

6. Before spraying herbicide, secondary dilution is required

Some farmer friends directly pour herbicide into the sprayer and stir it casually before finishing. This method of mixing the chemical is very unscientific. Because most herbicide products come with adjuvants, and adjuvants play a role in penetration and synergy, they are usually relatively viscous. If poured directly into the sprayer, they may sink to the bottom of the bucket, causing the adjuvant to wrap around the herbicide so that it cannot dissolve. This leads to only two consequences: one is that after all the chemical has been sprayed, some herbicide is still at the bottom of the bucket undissolved, causing waste; the other consequence is that the herbicide sprayed at the beginning is very light, while the herbicide sprayed at the end is very heavy. Therefore, when using herbicide, be sure to pay attention to secondary dilution.

The correct preparation method is the secondary dilution method. First, add a small amount of water to the mother liquor, then pour it together with a certain amount of water into the sprayer, then add the required amount of water and stir until it is diluted to the required concentration.

Never pour in the chemical first and then add water, because the chemical will easily deposit at the suction pipe of the sprayer, making the liquid sprayed first highly concentrated and likely to cause herbicide damage. Nor should a large amount of water be poured directly into a sprayer already containing the chemical, because the powdered chemical will often float on the water surface or form small clumps and be extremely unevenly distributed. This not only fails to guarantee the effect but also easily blocks the nozzle holes during spraying. In addition, the liquid should be prepared with clean water.

7. Herbicides must be used strictly according to regulations, and excessive use must be avoided

Some farmer friends will re-spray a few more times in places with thick weeds when spraying herbicide, or, afraid of waste, pour all the remaining herbicide at the end onto the last plot. This practice can easily lead to herbicide damage. Because herbicide is safe for wheat at normal use concentration, but if used excessively, wheat itself cannot break it down, and it will cause harm to wheat.

8. Yellowing and seedling suppression in wheat after spraying herbicide is normal

After some herbicides are used, wheat will show short-term yellowing of leaf tips. This is a normal seedling suppression phenomenon and generally recovers on its own when wheat turns green. This phenomenon not only does not reduce yield, but can instead promote increased wheat yield, so farmer friends do not need to worry when encountering this phenomenon.

9. Strictly control temperature

Finally, we need to pay attention to the weather temperature and humidity when weeding wheat. When using the chemical, the average temperature should be above 6 degrees, and the best time is between 10 a.m. and 3 p.m. If the soil is relatively dry, pay attention to increasing the amount of water used. If the soil has standing water, it will affect the efficacy of the wheat herbicide.

Therefore, when applying wheat herbicide, seize the timing, consider many aspects, and use the chemical in time to lay the foundation for high wheat yield. After wheat is sown and emerges, a series of management tasks will also begin. Weeds in wheat fields must be removed early, so this knowledge will be needed immediately, and saving it in advance is very beneficial.