first
Fenoxaprop-p-ethyl+safener belongs to aryloxy herbicide.
It belongs to phenoxypropionic acid herbicide, acetyl coenzyme A carboxylase (ACCase) inhibitor, and systematic selective stem and leaf treatment. After being absorbed, the stems and leaves are transferred to leaf bases, internode meristems and root growth points, which are quickly transformed into harmful substances, damaging weed growth points and meristems, leading to tiller base necrosis, leaves turning green and purple, and finally dying. Commonly used products in the market are 6.9% EW and 10% EC. The application shows that it can control and inhibit many gramineous weeds in wheat fields, especially wild oats and milkweed. Advantages: normal use, high safety to wheat under non-extreme weather conditions, and few serious irreversible phytotoxicity; It can be compounded with a variety of chemicals, including broadleaf weeds and gramineous chemicals, such as sulfuron-methyl, isoproturon, tribenuron-methyl, azosulfuron-methyl, bromoxynil and so on. It can improve the efficacy and expand the weed control spectrum; The cost is relatively low and the cost performance is high; The application technology of wheat farmers is relatively mature. Disadvantages: the effective weeding spectrum is narrow, and the control effect on many gramineous weeds such as Aegilops tauschii, Bromus, Lolium multiflorum, grass, hard grass and so on is poor. , rapidly rising and spreading in wheat fields, very poor, dwarfed by some newly developed high-efficiency pesticides, and ineffective for broadleaf grass; The combination with some chemicals, such as carfentrazone, phenoxycarboxylic acid and bentazon, is limited, and these chemicals are easy to cause phytotoxicity, especially when it is mixed with carfentrazone in emulsifiable concentrate.
At first, fenoxaprop-p-ethyl could only be used to control gramineous weeds in broad-leaved crop fields, and it was registered for use in winter wheat fields in the 1990s, which was the earliest pesticide used to control gramineous weeds in winter wheat fields. According to the existing data, it can also be used in wheat fields after adding safety agent. There are also registered varieties used and compounded in rice fields, which show good control effect on refractory barnyard grass, but the safety risk is great, so the agricultural authorities do not advocate registered application. Comprehensive analysis shows that this product still has a certain market in winter wheat field, but it is difficult to have room for growth and tends to decline gradually. Compound mixing is an effective measure to expand the market.
second
Methyldisulfonic acid+safener belongs to sulfonylurea herbicides.
It is an inhibitor of acetolactate synthase (ALS) and is treated by internal inhalation and selective stem and leaf treatment. After the drug is absorbed by the stems and leaves, it prevents the biosynthesis of branched-chain amino acids, and then stops cell division and gradually dies. The commonly used products in the market are 3% oil suspension or 30g/L oil suspension mixed with barrels, and there are also 1% oil suspension in the market recently. Advantages: high activity, low dosage, no more than 1.2g of active ingredients per mu; Its weed control spectrum is wide, and it has a good control effect on almost all gramineous weeds in wheat fields at present, especially on rapidly spreading malignant weeds such as Aegilops tauschii, Lolium multiflorum and Kentucky Bluegrass. It is the most extensive and effective herbicide for controlling gramineous weeds in wheat fields at present, and only other similar pesticides can compare with it. Disadvantages are strict medication technology: first, the dosage is strictly limited, and the maximum dosage of active ingredients per mu cannot exceed1.2g; Second, the medication cycle is relatively short, and the best medication cycle is 1 third lobe of heart to spring. It is forbidden to use drugs before the third leaf and after the height of 30 cm in spring, otherwise it is easy to cause phytotoxicity and difficult to recover; Third, the drug abuse environment is strict. The temperature is below zero or frosty at night, and the maximum temperature during the day is below 8 degrees. Drugs are not recommended. It is not allowed to use drugs in low-lying and waterlogged areas or fields after rain. Fourth, some varieties are sensitive, and experiments should be carried out before the promotion of strong gluten and horny wheat; Fifth, the compound chemicals are limited and cannot be compounded with chemicals with long residual period; Sixth, the sick seedlings are weak, and the fields with exposed seeds in autumn cannot be used.
At present, many kinds of gramineous weeds are spreading rapidly in wheat fields, and other pesticides are difficult to be effective. Only this product stands out. At present, the patent protection period has passed in China, and it is expected to be faster. There are 8 original drug research enterprises and 23 preparation production enterprises in the effective registration state, and the number of enterprises applying for registration test is also increasing rapidly, which provides strong support for market application. In the face of the fact that this product has suffered a lot of drug damage in wheat fields, we can neither be bitten by a snake once, but also be afraid of the rope for ten years, and we can not forget the lessons from the past and effectively improve the level of scientific drug use. With the continuous improvement of application technology, the phenomenon of drug injury will be reduced or will not happen again.
third
Compound agent of methyl disulfonate and methyl iodide
Selective stem and leaf treatment agent. Methyl disulfonate is as described above and will not be repeated here. Although the classification status, action mechanism and application method of metsulfuron-methyl are the same as the former, the weeding spectrum is completely different. The control target is a variety of broad-leaved grasses in wheat field, which is safe for wheat, has no adverse effect on subsequent crops and has good environmental compatibility. This drug combines two highly active pesticides with different weed control spectra, showing a certain synergistic effect. Only 3.6% of the water dispersible granules in the market are mixed with safeners. Advantages: high activity, low dosage, and the dosage of preparation per mu is 25-35 ml; Wide weed control spectrum, good control effect on almost all gramineous weeds and common broad-leaved weeds in wheat field, and it is an excellent herbicide with the widest weed control spectrum and good control effect in wheat field at present; It is convenient to use, does not need to be compounded with other drugs, and saves time and labor by spraying drugs once. The disadvantage is that the application technology is strict. The registered valid status of this product only includes 6 sub-packaged products, but there are informal registered follow-up products in the market. Because the product is a high-end pharmaceutical compound, it has excellent performance and mature application technology, and has a good application prospect.
fourth
Selective internal absorption soil treatment agent compounded with furosemide, flufenacet and diflubenzuron.
Fulong, a carotenoid synthesis inhibitor, was selectively treated before or after seedling. The drug was quickly poisoned after being absorbed by roots and buds, and the plant died of green albinism. At first, it was mainly used in cotton, peanut, sunflower and pea fields abroad, and later it was used in rye and wheat fields to control a variety of gramineous and broad-leaved weeds. Flufenacet belongs to aryloxyethylamines, which is an inhibitor of cell division and growth and a selective systemic soil treatment agent. Application before or early after seedling can control many gramineous weeds and some broad-leaved weeds in wheat field. It is also used in soybean, potato and sunflower crops abroad, which is safe for crops and friendly to the environment. Difluoropyridine, a pyridine formamide, is a carotenoid synthesis inhibitor. Used for selective internal absorption of soil or early treatment of stems and leaves. Weeds are mainly absorbed by the roots of young buds. Carotenoids in plants are reduced after sensitive weeds are damaged, which further destroys chlorophyll synthesis, cell rupture, bud fading or whitening and death. The pesticide can prevent and kill a variety of broadleaf grasses and Kentucky bluegrass in wheat fields. It is characterized by a wide application period and can be used for soil treatment before or early after seedling. The effective weeding film formed on the soil surface lasts for a long time, and the efficacy of weeds with delayed germination in spring is also stable; Good miscibility, can be compounded with a variety of agents, showing better performance. It is also used in carrot, sunflower and pea fields abroad, and compound soil treatment agent is also used in garlic fields at home. Previously, soil treatment was rarely used in winter wheat fields, and it was only a single dose, which did not attract the attention of the industry. This drug combines three kinds of pesticides with different weeding spectra and their own strengths, and can control almost all weeds in wheat fields. From the theoretical and practical application results, it greatly promoted the soil removal in wheat fields and enriched the chemical removal measures in wheat fields. Compared with stem and leaf treatment, it shows many advantages: it greatly advances the application period, completely avoids the influence of changeable extreme temperature, is beneficial to ensuring and exerting the drug effect, and is not easy to produce phytotoxicity; Medication is very convenient. Autumn sowing wheat fields are generally flat, not affected by grass seedlings, and easy to spray drugs evenly. There are few other crops in the field, so don't worry about the damage of drifting pesticides. The wheat field sown after soil preparation has no weeds on the surface, and the weed seeds in the soil develop consistently, which can improve the control effect; It prevents weeds from competing with wheat for water, nutrients and space before germination, which is very conducive to early growth and strong grass, improving effective tillering, ensuring safe winter of wheat and laying the foundation for high yield and bumper harvest; Generally, slight phytotoxicity has sufficient recovery time, and it is beneficial to reduce the harm of residual phytotoxicity in soil to the next crop after early application. Disadvantages: there are certain safety risks to exposed wheat seedlings; The control effect on some refractory malignant gramineous weeds is not good; The operating cost of enterprises is high. At present, there are only 33% suspending agents in the domestic market, and the valid registration status is up to 2065438+June 2007. According to the information released by the Institute for Drug Control, the relevant materials will be officially registered after completion. Due to the traditional advantages and price of chemical pesticide removal in wheat field, the application and promotion of this product is lower than expected, but the appearance of this product will definitely affect the drug use pattern of chemical pesticide removal in wheat field. According to incomplete statistics, in the wheat fields registered for testing, 56 production enterprises applied soil treatment agents before and early after seedling, and 10 enterprises obtained the registration certificates of relevant APIs. The application and influence of these product resources deserve attention and expectation.
fifth
The active ingredient is diflubenzuron.
At present, three manufacturers of the drug have obtained registration certificates, two of which are 50% wettable powder and one is 500 g/L suspending agent. The existing registered application test and field application show that diflubenzuron is compounded with many chemicals, including soil treatment agent, stem and leaf treatment agent, gramineous herbicide and broadleaf agent, such as tribenuron-methyl, isoproturon, tribenuron-methyl, flufenacet and so on. The processing dosage forms are wettable powder, water dispersible granule and suspending agent. The introduction of various compound agents will certainly broaden the application prospect of diflubenzuron.