Hormone herbicides usually have the advantages of good conductivity, broad herbicidal spectrum, low cost, and are not prone to resistance, and are widely used around the world. In recent years, two hormonal herbicides with novel aryl picolinate structures-fluoropyridine and halauxifen-methyl-have been developed and launched, injecting new vitality into the development of the hormonal herbicide market. Compared with other hormonal herbicides, fluopyridine and halauxifen-methyl have lower dosages, wider herbicidal spectrum, are environmentally friendly, and are new tools for the management of resistant weeds.
Mechanism of action and application
Halauxifen-methyl contains a new aryl picolinate structure and is a hormone herbicide. The Herbicide Resistance Action Committee (HRAC) classifies it as Group O (Auxin Mimics). The mode of action of other hormonal herbicides is similar. It interferes with the normal physiological and biochemical functions of plants by binding to hormone receptors in plants, thereby causing the death of sensitive plants. After application of pesticides, the above-ground parts of grass weeds grow abnormally and appear swollen. Broad-leaf weeds grow deformed, vascular tissue is destroyed, and then die.
Compared with other herbicides with mechanisms of action, especially herbicides with inhibitors of acetyl-CoA carboxylase (ACCase) and acetolactate synthase (ALS), hormonal herbicides have many and complex target sites. Therefore, resistance is less likely to develop and the degree of resistance is low. Halauxifen-methyl acts on the two most important target sites of hormonal herbicides-TIR1 and AFB5. And its unique way of binding to receptors, especially its tight binding to AFB5, allows its dosage to be significantly reduced compared with other hormonal herbicides. Halauxifen-methyl has a different receptor than traditional synthetic hormone herbicides, so there is no cross-resistance with this type of herbicide, nor with herbicides with other mechanisms of action.
The mechanism of action of halauxifen-methyl is novel, making it suitable for resistance management and addressing known resistance issues. It includes inhibitors of ALS, ACCase, hydroxyphenylpyruvate oxidase (HPPD), as well as weeds that develop resistance to herbicides such as glyphosate, dichloroquinoline, glyphosate, and triazine. It has excellent activity against resistant barnyard grass in rice fields.
Halauxifen-methyl is mainly absorbed through the leaves of plants, and a small amount is absorbed through the roots. It is transmitted in the xylem and phloem, and accumulates at the growing point to exert its effect. Halauxifen-methyl has a wide spectrum of weed control, and has good control effects on grass weeds such as barnyard grass, bald barnyard grass, rice barnyard grass, and millet, as well as grass weeds such as heterotypic sedge, oil sedge, broken rice sedge, fragrant aconite, and sunshine drift grass. It also has good control effects on broad-leaved weeds such as tilapia, Alisma orientalis, water amaranth, amaranth, ragweed, quinoa, small flying awn, mother grass, water lilac, Yujiuhua, Cigu , and Canger.
Halauxifen-methyl has unique selectivity and high safety to rice. The development company first developed it for rice, including direct-seeded rice fields and transplanted rice fields. In addition, by adding safeners, it is introduced into markets such as cereal crops, field crops (pre-emergence treatment), orchards, lawns, pastures, pastures, and water surfaces (ponds and lakes).
Halauxifen-methyl is fast-acting, kills grass completely without rebound, and has good therapeutic and eradication activity. After application, sensitive broadleaf weeds will take effect in 2 hours and will basically die after 3 days.
Halauxifen-methyl can provide good control effect at very low dosage. According to different weed species and application methods, the dosage of active ingredients is 5-50 g/hm2. Tests have shown that the dosage of halauxifen-methyl is 153 times lower than other commonly used herbicides in rice fields.
Halauxifen-methyl has strong miscibility and can be mixed with most commonly used herbicides in rice fields. It has a synergistic effect, is environmentally friendly, and is safe for other organisms. Compatible active ingredients include penoxsulam, cyhalofop-al, fenpyridine, bissotrione, fluopyron, pretilachlor, diflufenac, afenacetate, etc.
Halauxifen-methyl is environmentally friendly. It has very low toxicity to aquatic organisms and can be used on water surfaces (such as rivers, rivers, lakes, etc.). It is a low-risk product.
summary
Halauxifen-methyl is highly efficient and broad-spectrum, and is effective against broadleaf weeds, grass weeds and sedges. It can also effectively control weeds that are resistant to ALS inhibitors, ACCase inhibitors, HPPD inhibitors, triazine herbicides, propanil, quinclorac, glyphosate, etc. It has a wide range of applications. It can not only control weeds in rice fields, but also extends to non-agricultural fields such as corn, soybeans, orchards, pastures, ponds, lakes, industrial plots, and wildlife habitats. In addition, halauxifen-methyl has a low dosage, long lasting effect, is safe to non-target plants, and is environmentally friendly. As the resistance of barnyard grass in rice fields increases year by year, the development of resistance management tools in related fields will take a certain amount of time. Therefore, halauxifen-methyl is currently an ideal tool for the control of barnyardgrass in combination with other agents such as cyhalofop-al, oxazopyramide, etc., and is worthy of attention.
