Mechanism of action and use of safety agents in nicosulfuron preparations

In fact, herbicide safety agents have never been a rare thing. Since 1947, when Hoffman found that tomatoes treated with 2,4, 6-DDT were less sensitive to herbicide 2, 4-drip, the research on safety agents has gradually attracted attention and been commercialized. In the absence of new compounds, safety agents are increasingly of research value as compounds that can expand the use patterns of existing herbicides and encourage toxicological compatibility.

With the extensive development and application of sulfonylurea, imidazolinone, cyclohexanedione and isoxazoldione herbicides, more and more studies on the activity of related safety agents have been reported. According to the use of dibenzoxazolic acid, the safety agent of the sulfonylurea herbicide nisulfuron in corn fields, compared with the use of nisulfuron alone, the use of safety agent not only reduces the crop damage, but also can be used to solve the problem of difficult weed control, and expand the application scope and effectiveness of the herbicide.

At present, the maize post-emergence herbicide market is dominated by nicosulfuron, nitrosulfone, atrazine and their compound products. Nicosulfuron will be affected by high temperature, weather and other conditions in the process of use, and the use of a little careless will cause corn harm, seriously affect the growth of corn. However, in case of rainy weather, the weeds are easy to turn green, and the dead grass is not complete. With the introduction of safe fumisulfuron, the traditional understanding of fumisulfuron has been completely overturned, and the problem of poor safety caused by whole-field spraying of corn seedlings has been completely solved. During the 2-9 leaf stage of corn, whole-field spraying can be used, and a good solution has been provided for the mechanical whole-field spraying of large growers. The product is especially suitable for use in North China under adverse weather conditions such as high temperature and drought, and can greatly improve the safety and efficacy of nicosulfuron. Due to the emergence of corn special safety agent, nimosulfuron has replaced nimosulfurone and won a part of the market share. The introduction of safe pyrismil will certainly lead to a revolution in weeding after maize field seedling.

The advantages of safe pyrimol over traditional pyrimol herbicides are as follows:

Product function Traditional smoke safety smoke

The efficacy of the product is good for annual grasses and some broad-leaved weeds. It has special effects on Ma Tang, setaria, quinoa, Chinese seed, etc. Dead grass does not rebound completely

Safety Some corn varieties are easy to produce drug damage, in drought, high temperature, excessive drug use, repeated spray and other conditions of corn will produce drug damage to the common corn varieties are highly safe, high temperature, drought conditions are not easy to produce drug damage, the amount of over times is also safe.

Usage During the maize 2-5 leaf stage, avoid the maize center leaf interrow spray and do not use a motorized sprayer. Corn 2-8 leaf stage, according to the weed situation of the whole field spray, without direction, can be used for machine spraying.

Yield increase effect has no yield increase effect. It has health care effect on corn and promotes corn yield and income.

At present, there are two main formulations of safe pyrimes in China:

1, nicosulfuron + dibenzoxazolic acid (4:1~2)

2, nicosulfuron + synergistic additive B100168+ safety agent MON13900 (furazole)

Safety agent: dibenzoxazolic acid

1, bibenzoxazolic acid is to reduce or eliminate herbicides to crop damage additives:

The use of safety agents can not only improve the resistance of crops, but also solve the problem of the control of difficult weeds, and expand the application range and effectiveness of herbicides. Dibenzoxazolic acid is an isooxazole safety agent developed by Aventis, which is used to control annual and perennial weeds in corn fields.

2. Mechanism of action of dibenzoxazolic acid:

Dibenzoxazolic acid increases the selectivity of maize by reducing the conductivity of maternal sulfonylurea. Greenhouse studies have shown that this is due to its ability to reduce the conductivity of sulfonylurea while increasing its detoxification metabolic rate. Nicosulfuron added with safety agent can be sprayed in the whole field of maize 3-10 leaf stage, without orientation, and can be used for mechanical spraying. It is not clear whether the safety agent can enhance all three of the sulfonyl degradation pathways in corn at the same time, or only selectively improve one of them. There are three main metabolic pathways in maize; Hydrolysis of sulfonylurea bridge, amino-deacylation, oxidative metabolism of dimethoxy-pyrimidine ring.

3. Development and use of dibenzoxazolic acid:

(1) Dibenzoxazolic acid is an isoxazole safety agent developed by Aventis, which is used to control annual and perennial weeds in corn fields. Use as a safety agent for corn herbicide formamidsulfuron, improve the safety of corn. The results showed that the mixture ratio of formamidsulfuron and safety agent (dibenzoxazolic acid) was 1:1, and the safety of crops was good.

It is mainly used to control grass weeds and some broad-leaved weeds in corn fields, where it is often mixed with sodium iodomethyl sulfonon. The results showed that the combination of formamide sulfonon with 30-45g.a.i./ ha of dibenzoxazolic acid at a dose below 30-45g.a.i./ ha could control many important grass weeds and broad-leaved weeds in the major maize producing areas of the world. If 1-2g.a.i./ha iodomethyl sulfuron is added, the control effect on some broad-leaved weeds can be significantly improved. There are three domestic enterprises producing dibenzoxazolic acid: Changzhou Runfeng Chemical production is large.

(2) Bayer and DuPont reached a herbicide swap transaction:

A pre-budding glyphosate-resistant corn herbicide (DuPont) = isoxazolone (Bayer) + dibenzoxazolic acid (Bayer) + sulphosulfuron (DuPont), DuPont also noted that the entry of isoxadifen will give greater flexibility to some DuPont developed sulfonylurea corn herbicides. They include sulphosulfuron (Resolve), Steadfast(Fumiosulfuron +rimsulfuron), Accent(fumiosulfuron +rimsulfuron) and Stout(fumiosulfuron + thiophensulfuron).

(3) In 2010, Bayer launched a new corn herbicide Soberan and obtained registration in Brazil. Soberan= cyclosulphonone + dibenzoxazolic acid to control annual grasses and broad-leaved weeds in corn fields. Among them, cyclosulfosterone is a triketone corn herbicide developed by Bayer company in 2007. Its activity is higher than that of nitrone (nitrone, methyl sulfosterone), and it is safe for crops.

(4) In 2012, Bayer corn field herbicide Laudis was registered in Italy and Greece, Laudis= cyclosulphonone + dibenzoxazolic acid. It is a suspended formulation used to control annual grasses and broadleaf weeds in maize.

4. The use cost of dibenzoxazolic acid:

Generally, domestic herbicide manufacturers in accordance with the ratio of dibenzoxazolic acid: niazsulfuron =1~2:4 (effective amount), calculated at a high price of 550,000 / ton, the cost of dibenzoxazolic acid per mu is 0.55~1.1 yuan. Bibenzoxazolic acid safety agent has an effect on the efficacy of nimosulfuron, which can reduce the herbicidal effect by about 10%, so the actual product formulation can appropriately increase the effective amount of nimosulfuron to improve the herbicidal effect.

The second: MON13900 (furazole)

MON13900 is a safety agent developed by the Monsanto Company that enables many herbicides to be used safely on graminae crops, particularly in reducing maize damage caused by sulfonylurea herbicides, including NC-319 developed by Nissan Chemical Company. MON13900 can reduce the harm caused by several herbicides. Similar to other dichloroacetamide compounds, it is an excellent safety agent for acetanilide herbicides and thiocarbamate herbicides. Its unique feature is that it can be successfully used as a safety agent for a series of sulfonylurea and imidazolinone herbicides in grass crop fields without affecting the control of weeds.

1, mechanism of action: sulfonylurea, imidazolinone herbicides for corn and other safety agents. Its effect is based on the herbicide can be quickly metabolized by the crop, so that the crop does not harm.

2, suitable crops: corn, sorghum, etc

3, safety: with sulfonylurea, imidazolinone herbicides used together can make crops such as corn free from harm. Safe for the environment.

4. Use method: herbicide safety agent. Herbicide safety agent for a variety of gramineous crops. Especially when used together with chlorpyrisulfuron, it can reduce the possible harm of chlorpyrisulfuron to corn.