How long after sowing wheat is herbicide better? On what basis?

In previous years, it was usually November, but this year is different. Up to now, there are still many places in Shandong, Hebei, Henan and other regions that have not grown wheat, so it is impossible to see the moon this year. After wheat is planted, farmers are more concerned about herbicides.

use. In the Little Helper High Yield***, the topic of discussion is how many days after wheat sowing is better to spray herbicides. Some say that it is better to spray herbicides after 40 days of sowing for wheat, while others say it is better after 50 days. Who is right and who is wrong? Or is there a better time?

The best time to use herbicides in wheat is precisely determined by the number of leaves in the wheat. We often say that the 3-5 leaf stage of wheat is the best time to spray herbicides. Therefore, the choice of 40 or 50 days after sowing should be compared with the 3-5 leaf stage of wheat.

Chemical weeding of wheat before winter has the characteristics of weeds tender, tender tissues and pesticide resistance.

Poor, low dosage, high control effect, thorough weeding, low control cost, safety for wheat and stubble crops, etc. Generally, wheat is sown at the right time, and weeds basically come out about a month after sowing (accounting for more than 95% of the total grass volume).

At this time, the wheat grows about 3-5 leaves, which is the best time to weed the wheat field. After sowing, there is more rain, the soil moisture in the field is better, and the weeds emerge faster, and the soil moisture is insufficient after sowing, which will affect the emergence of weeds. However, the spraying should not take place later than mid-December.

Why is it better to use herbicides in wheat fields at this time? At this time, the amount of weeds unearthed in wheat fields accounts for about 80% of the total, and the resistance of weeds to herbicides is very poor, so the effect of herbicides is better than in other periods.

So, on the day of spraying, when is the herbicide effective? The most suitable time of day is 10:00 a.m. -12:00 a.m

00。During this time, the temperature is at its highest, and most of the weeds' stomata are open, and the liquid can be absorbed quickly. But many of our peasant friends are big landowners, such as hundreds or even thousands of acres.

If you only take your medicine between 10 a.m. and 12 a.m., you may not have enough time. If this is the case, it can be postponed until 3 p.m. Note, however, that afternoon spraying is not as effective as morning

Forty days or so is best. Because after sowing, if the temperature is right, it takes about 7-10 days for the wheat to emerge, and by 40 days, most wheat has 3-5 leaves. According to the law of weeds in wheat field, the peak of wheat weeding for the first time, that is, the 3-6 leaf stage, accounts for about 80% of the total grass output, and there are many types of grass, large grass output, small weeds, weak pesticide resistance, and the most serious damage, therefore, this is the best period for spraying herbicides, and the most suitable herbicides can be selected according to different weeds for weeding.

It is better to sow for a month, and wheat seedlings can grow after a month of sowing, and the effect of herbicides is better at this time. This is due to the slow growth rate of wheat seedlings, and herbicides can only be used after waiting for them to grow, so as not to affect the growth of wheat.

Generally, the weeds are basically out of the wheat about 1 month after sowing (accounting for more than 95% of the total grass), and the wheat is about 3 5 leaf stage at this time, which is the best period for weeding in wheat field.

After sowing, there is more rain, the field moisture is good, and the weeds emerge quickly, but the moisture is insufficient after sowing, and the weed seedlings will be affected. However, the latest spraying time should not exceed mid-December.

Herbicides are generally sprayed about 30 days after sowing wheat. That is, in early November, wheat grows to about 4 or 5 leaves, and weeds such as wild wheat and knotted wheat grow to about 2 leaves, and the effect of medicine is the best at this time!

Wait until the wheat is a palm's height before applying herbicides, if you shoot too early, it may affect the growth of the wheat.

Wheat can generally be treated with herbicides 40 days after sowing. At this time, the wheat is in the 4-leaf or 4-leaf 1-heart stage, and it is more tolerant to herbicides, so it is safer to apply herbicides at this time. In addition, when the wheat is 4 leaves, most of the weeds have come out, and the grass age is small, the wheat has no tillering, and there are not many leaves, so it is easier to kill weeds with herbicides, and the efficiency will be higher.

1. The time of the first use of wheat is 40 days after sowing, when wheat is in the 4-leaf or 4-leaf 1-heart stage, which is more tolerant to herbicides, and it is safer to apply herbicides after 4 leaves; Moreover, when the wheat is in the 4-leaf stage, most of the weeds have come out, the grass age is relatively small, the wheat has no tillering, and the leaves are not many, so it is easier to kill the weeds, and the herbicide is very efficient at this time. 2. Generally, the herbicide will be marked with 2 can be used, or 5 can be used, then the 2 and 5 mentioned here refer to the minimum temperature, that is, the minimum temperature can only be used for control with herbicides above 2, and before and after 2 days after the herbicide, it should not be lower than this temperature.

Planting wheat is inseparable from August soil (ancient calendar), in fact, it is "cold dew mountain wheat, winter solstice planting Jingyuan", the time of planting wheat in the northern region is: the solar calendar is October 5th to 15th, and the ancient calendar is the best time to plant wheat from mid-to-late August to early to mid-September. With the growth and development of rice seedlings, the germination period of weeds, wheat is generally 40 days after sowing, and the three-leaf to four-leaf stage of rice seedlings is actually the germination of weeds in the two-leaf stage, in fact, it is the ancient calendar of early to mid-to-late October to select a sunny day without frost and dew, and the ambient temperature is above 10 degrees Celsius for 10 minutes to beat the herbicide is more reasonable.

If you are busy and miss the great opportunity to kill herbicides in winter, you need to hurry after the Lunar New Year, in fact, before the wheat returns to green, and immediately kill herbicides in the middle or late of the beginning of the new year, and it is more suitable to choose sunny days without dewdrops, and the ambient temperature is more suitable for spraying above 10 degrees. It is more appropriate to apply herbicides one month after wheat sowing and germination. The main problem is that the wheat planted in mid to late October can be beaten after six or seven days.

It should be like that in terms of days, but there are many elements to be learned, such as seedling conditions and environmental temperature. If wheat is planted, if the seedlings are good, they will <>

The rice seedlings are about three or four inches high from the soil, and most of the weeds in the wheat fields are unearthed. If the seedlings are not in good condition when planting, and the rice seedlings are excavated slowly, the rice seedlings will be scarce, short, the soil layer is dry, and no weeds can be seen, even after planting for one month, it is not suitable for herbicides. In this case, herbicides are not only harmful to the growth and development of rice seedlings, but also cannot have the actual effect of hoeing.

The second is the ambient temperature, when the herbicide is used, the ambient temperature should not be less than 5 degrees Celsius, if the ambient temperature is less than 5 degrees, it will also endanger the potency.

After planting wheat, the criterion for weeding the wheat is that it is best to kill four or five leaves of wheat. At this time, the wheat is strong, the grass is weak, grasp the best time, use reasonable chemical preparations, under the right weather conditions, the right time period, under the premise of ensuring life safety, properly implement the wheat weed, the actual effect is the best.

After the wheat is sown, the herbicide should be applied after the wheat has returned to green. And the herbicide should be diluted before use, pay attention to a reasonable proportion.

: Wheat is suitable for herbicides at 5-6 leaves. The use of wheat herbicides is very strict, generally wheat over 4 dozen herbicides. Wheat is treated with herbicides in early to mid-November. Wheat can now be sprayed with herbicides at 3-5 leaf stages after sowing.

Apply herbicide every other week, herbicide should not be used frequently.

Herbicides were best applied after 4 leaves of wheat to before jointing.

Wheat topdressing is chaotic

1. The topdressing time of wheat is generally three stages: the green stage of winter wheat after the beginning of spring, the growth of wheat to the inverted second leaf stage, and the early stage of heading and flowering. Specifically, it should be determined according to the growth of wheat plants, an appropriate amount can be used, and it must not be excessive, otherwise fertilizer damage will occur.

Wheat regreening is a very important topdressing for wheat, and it is topdressed in March, because March is a normal year for wheat. Top dressing in April every year is because the wheat at this time has entered the jointing stage, which is more conducive to the high yield of wheat in the later stage.

2. Check the growth of wheat. If the wheat grows normally and there are no yellow seedlings, purple seedlings, red seedlings and other phenomena, then urea can be topdressed, about 30 to 40 catties per mu. On the contrary, if the wheat is short and has purple seedlings, red seedlings and other symptoms, it is necessary to apply compound fertilizer, about 40 to 50 catties per acre.

At the same time, spraying some full-effect supplementation or wheat-specific foliar fertilizer is more conducive to the normal growth of wheat.

3. Whether the wheat is applied with base fertilizer. When sowing wheat, the vast majority of farmers will choose to use base fertilizer, however, there are a small number of farmers who do not use base fertilizer, in this case, there is no land with base fertilizer, top dressing to use compound fertilizer, and the amount per mu is 70 to 80 catties, or even about 100 catties. The plots with base fertilizer, combined with the first factor, under normal circumstances, can be top-applied urea, about 30 to 40 catties per mu.

4. Judge according to soil fertility. Some plots themselves are relatively fertile, wheat grows well, and urea can be selected when topdressing, about 30 to 40 catties per mu. Due to the influence of a variety of factors, such as excessive use of chemical fertilizers and pesticides all year round, the soil is relatively poor and even compacted, in order to promote the growth of wheat, it is necessary to choose compound fertilizer when topdressing.

According to the reaction of most farmers, the farmers who choose urea when topdressing account for a relatively large proportion, and the farmers who compound fertilizer are relatively few, after all, farmers will calculate the cost of farming, and the ** of compound fertilizer is still higher than that of urea**.

In the actual planting process, there are some farmers, choose top dressing 2 times, the first time to apply urea during the regreening period, the second time to apply compound fertilizer during the heading period, this practice, everything is normal, two times is definitely better than one time, however, some farmers will calculate the cost, one is the cost of fertilizer, the second is the cost of labor, and the third is the cost of wheat yield and wheat price source. Therefore, many farmers don't like to chase it twice, thinking that it is not worth it.

It was just planted, and the surface of the fief was better when it was not unearthed.

Generally speaking, it is OK when it is in the seedling stage. To choose the most toxic and small ones, it will not affect the wheat, pay attention to the choice of varieties, but also pay attention to the specific ingredients.

Wheat field with chemical pesticides weeding, some people spray soil layered closed herbicides before sowing or before sowing, some people spray weeds before winter after seedlings weeds leaf stem systemic delivery herbicides, and some areas are accustomed to spraying after the year wheat back to the jointing stage, subconscious spraying time difference is also large, which specific time range spraying herbicides is the best, according to the packaging instructions, chemical weeding in winter wheat fields, before the seedling year, wheat 2 4 leaf stage, weeds 3 5 leaf spraying herbicides is the best. According to the actual pesticide work experience in the hometown for many years, the best time is from the end of the first month to February of each year.

At this stage, several small grasses in the wheat field begin to bud as the temperature gradually rises. If a few days later, the wheat sprouts rapidly, and the medicine touches the flowers and leaves, and all kinds of grasses are also developing at a rapid rate. The problem of herbicides is the best period for chemical weeding in the wheat standing up period, and all kinds of weeds slowly sprout with the regreening of wheat, such as broad-leaved weeds such as Artemisia annua, chrysanthemum, quinoa, etc.

10g of benzuron wettable powder can be used per mu with 2,<>

4-D butyl acetamiprid 50mi (not suitable for re-replacement after heading) mixed spraying. It is best not to use metsulfuron-methyl, chlorsulfuron-methyl and mixed pharmaceutical preparations, because these herbicides have a certain impact on the next crop of corn. For gramineous weeds with strong resistance, it is recommended to eliminate them with human resources.

Wheat herbicide as far as possible before the year to spray, the grass is small, you can see clearly, after the end of the year wheat covers the ground, there are no weeds at all, the liquid medicine is sprayed on the wheat, the actual effect is very poor, so many people reflect the effect is not good, the root cause is the wrong time. After the germination of wheat, the weeds are small and tender, <>

At this time, when the rice seedlings are in two leaves and one heart, the rice seedlings are not sealed, the weeding effect is the best, the contact area of the weeds is expanded, the weeds are the worst resistance, and the dose is also very low under the premise that taking medicine is the ideal, but this is only to remove the weeds that germinate early. In winter, weeds have just germinated and grown, and the resistance is very low, and the young seedlings are easy to knock down, and the wheat has just been dug out and not covered, and the hoeing effect is remarkable. Therefore, after the wheat is excavated and the growth and development are stable, that is, in the case of 4 leaves of wheat, the average daily temperature is about 8 degrees, at least not lower than 3 degrees.

Different herbicides are used for different times, and the appropriate herbicide should be selected according to the specific land conditions and the type of grass.