What are the herbicides after corn seedlings? What kind of herbicide is effective? When will you play?

Corn post-seedling herbicides are used every year. The application of corn post-seedling herbicides has a great impact on the following crops. What are the post-seedling herbicides? What kind of herbicide is effective?

First of all, there are many formulations of corn herbicides, such as nicosulfuron, nitrosulfone, 2-dibutyl, chlorofluoropyloxyacetic acid, trimethopyr, etc., but the first two are commonly used, that is, nicosulfuron + nitrosulfone, and in the actual drug application process, atrazine (with a certain sealing effect) will be added to form a compound. It is obvious that there are three commonly used formulations: atrazine nicosulfuron, nicosulfuron atrazine atrazine, nicosulfuron atrazine nitrosulfonone, here are the advantages and disadvantages of these three agents.

1. Atrazine + nicosulfuron

The formula has been used for a long time, and it is generally sold with 4% nicotinic acid on the market. If atrazine is used, there are 2 kinds of nicotinic acid with 20% content and 30% content, and the total content is 24% or 34%. This formula can control most of the weeds in corn fields, such as Digitaria, amaranth, duck foot grass, barnyardgrass, etc., but it has no effect on Reed.

The advantage is that the price is cheap, retail to buy, one mu of land is 4-5 yuan, the disadvantage is also obvious, there are two points, one is the slow death of grass, 20 days later will see the effect, second, weeds are resistant to it, in some areas, the weeding effect is general.

2. Nitrosulfone + atrazine

The common content of this formula is 55% (5% nitrafenone + 50% atrazine) or 53% (15% nitrafenone + 38% atrazine). It can also be used to control broad-leaved grass, sharp-leaf grass and sedge in most corn fields, but the effect of headache Reed is also average.

The advantage of this formula is that it takes effect quickly. About 7 days later, you can basically see that weeds die or begin to die. There are also two disadvantages: one is that the price is slightly more expensive, if you buy zero, the price is about 8-10 yuan per mu of land, and the other is that the use of technology is not in place. Weeds are easy to rebound in the later stage.

3. Nicosulfuron + nitrosulfone + atrazine

The ternary compound is relatively popular in recent years, with a common content of 28% (2.5% nicotinyl + 5.5% nitrate + 20% atrazine, or 3% nicotinyl + 5% nitrate + 20% atrazine). It combines the characteristics of nicotinic acid and nitrate sulfonate. his men are more extensive in the weeding spectrum, and for common reeds, the control effect is good at the 2-4 leaf stage, and no matter how big it is, it has a little inhibitory effect. Let it no longer continue to grow, in the speed of weeding, basically a week or so, can be effective.

However, there are also disadvantages, that is, the price is expensive, if you buy nothing, an mu of land will probably be between 15-20 yuan, and compared with nicosine + atrazine, one mu of land can beat it 3 mu of land, so, when using this chemical, the budget of the cost should be considered.

The above three herbicides, which are common post-seedling herbicides on the market, are also widely used by everyone, because each person's situation is different, you can choose according to the specific situation, and in addition, the herbicides mentioned above are suitable for ordinary field feed corn, but not for sweet corn, waxy corn or seed production fields.

When will the herbicide be hit after corn seedlings? How to play safe?

1. Administration time

As it takes 2-6 hours to absorb the herbicide after spraying, the weeding effect plays a very important role in this period. In the morning, noon or afternoon when the temperature is high and the weather is dry, because the temperature is high, the light is strong, the liquid volatilizes quickly, and soon after spraying, the liquid will evaporate, so you should choose to give the medicine before 10:00 and after 15:00, not only the effect has been achieved. people don't get heatstroke.

2. The method of administration

To tell you a method summed up in the actual drug administration process, under the premise of sufficient dosage, the more water the better (of course, it does not mean unlimited addition of water, relatively speaking). For example, if you buy a herbicide, it is recommended that one bottle of water per mu of land, that is, about 15 kilograms of water, is sprayed in an acre of land, but if you mix 20-25 kilograms of water, it is also sprayed on one mu of land. The effect is better than 15 kilograms of water.

In the vulgar point, a bottle of 1 bucket of water 1 mu of land into a bottle of 2 buckets of water 1 mu of land, interested friends can try, but note that the amount of spray must be uniform, must not be more than one piece of less.

3. The size of the grass

The best period for the use of post-seedling herbicides is the 3-5 leaf stage of corn, why?

When spraying herbicides after corn seedlings, many farmers have a misunderstanding that the smaller the weed, the less resistant the grass is, the easier it is to kill the grass. In fact, it is not, because the grass is too small to apply medicine area, the weeding effect is not ideal.

The best grass age is from 2 leaves and 1 heart to 4 leaves and 1 heart, when the weeds have a certain drug area, the weed resistance is not big, and the weeding effect is significant.

4. Maize varieties

At present, most of the herbicides after corn seedlings are nicosulfuron, and some corn varieties are sensitive to this composition and are prone to drug damage. therefore, the corn fields planting sweet corn, waxy corn and Denghai series can not be sprayed to prevent drug damage. For new corn varieties, please try them first and then popularize them.

5. Mixed use of pesticides

It is forbidden to spray organophosphorus insecticides 7 days before and after spraying herbicides, otherwise it is easy to cause drug damage. But can be mixed with pyrethroids and carbamate insecticides, spray should pay attention to avoid heart leaves as far as possible, anti-drug liquid perfusion.

Swedish flies and thrips have occurred seriously in some corn fields this year. Imidacloprid or acetamiprid can be used to control these two kinds of small pests, but do not mix them with post-seedling herbicides, although imidacloprid or acetamiprid are not organophosphorus. Because spray heart leaves are needed to control two kinds of small pests, if mixed spray heart leaves are easy to cause damage, you can spray herbicides separately: spray seedlings in front and spray herbicides separately. Followed by imidacloprid or acetamiprid spray leaves.

Above 5 points, we must pay attention to the spraying of herbicides after corn seedlings to avoid drug damage and affect the yield of corn.

In addition, under the reminder, when playing herbicides in summer, it is often high temperature and dry weather, so without affecting the efficacy, we must draw more water to improve the effect of weeding. And when taking medicine, we must pay attention to personal safety and take good measures to prevent heat!