Key Technical Points for Applying Chemical Herbicides in Vineyards

Key Technical Points for Applying Chemical Herbicides in Vineyards

Trifluralin. It is a selective pre-emergence soil treatment agent commonly used in orchards. It kills weeds after being absorbed through the coleoptile and hypocotyl, is ineffective against emerged weeds, and is effective against grasses and some small-seeded broadleaf weeds, with a residual effect lasting 75 to 80 days. It is low in toxicity to humans and livestock, low in toxicity to birds, and highly toxic to fish. It is volatile, easily photodegraded, has very low water solubility, and does not readily move through the soil layer. In vineyards, before weeds emerge, use 150 to 200 ml of 48% emulsifiable concentrate per 666.7 sq m diluted in 30 kg of water, spray on the soil surface, then shallow cultivate, and then compact the soil. Results are better when soil moisture is good.

Pendimethalin. It is a pre-emergence soil treatment herbicide and can be used for weed control in vineyards as well as corn, soybean, peanut, cotton, direct-seeded upland rice, potato, tobacco, vegetables, and many other crop fields. After weed seedlings absorb the agent, it binds with tubulin, inhibits mitosis in plant cells, and kills the weeds. It has good efficacy against annual grass weeds, some broadleaf weeds, and sedges such as barnyardgrass, crabgrass, foxtail, Chinese sprangletop, goosegrass, purslane, amaranth, lambsquarters, velvetleaf, black nightshade, rice flatsedge, and Cyperus difformis. It is basically ineffective against large-seeded broadleaf weeds and has poor efficacy against perennial weeds. It has strong adsorption in soil, shows no leaching, and has a residual effect lasting 45 to 60 days. It is low in toxicity to humans, livestock, birds, and bees. In vineyards, before weeds emerge, first irrigate, or take advantage of thorough rain, then use 100 to 150 ml of 33% pendimethalin emulsifiable concentrate per 666.7 sq m diluted in 30 kg of water and spray on the soil surface. Weed control is even better if rain occurs after application. It is more convenient to use than trifluralin, does not require soil incorporation, and saves labor and time, but its residual effect is somewhat shorter.

Oxyfluorfen. It is a contact post-emergence foliar treatment agent. It has a broad weed-control spectrum, a long residual effect, high activity, works better under good light, and is highly resistant to leaching. It has low toxicity. It can be mixed with many herbicides to broaden the weed-control spectrum and improve efficacy. It both prevents and kills many weeds, achieving twice the result with half the effort; it can be applied both before weed emergence and after weed emergence, making it convenient to use. It controls monocotyledonous and broadleaf weeds such as barnyardgrass, sesbania, velvetleaf, and field cress, and is especially effective against purslane. In vineyards, it is applied after weeds emerge, using 40 to 50 ml of 24% oxyfluorfen per 666.7 sq m diluted in 30 kg of water, sprayed evenly. In vineyards more than 2 years old, it is often mixed with pendimethalin and sprayed when soil moisture is present, while for newly planted young vines, directed spraying is used.

Glyphosate. It is a systemic, conductive, slow-acting, broad-spectrum, non-selective herbicide. After being absorbed through stems and leaves, it is translocated to all parts of the plant, interferes with protein synthesis, and causes plant death. It controls annual and perennial monocotyledonous and dicotyledonous weeds. During application, spray drift onto non-target plants must be prevented to avoid herbicide damage. After glyphosate enters plants, most of it is metabolized and decomposed after 6 to 7 days; after entering the soil, it combines with potassium, sodium, and other ions and then decomposes, leaving no residue in the soil, and the decomposition products are non-toxic. Use 200 g of 41% glyphosate isopropylamine salt per 666.7 sq m diluted in 30 kg of water for directed spraying.