The main weeds in the sunflower field include alfalfa, Syzygium sinensis, Suaeda, Poria, Setaria, Matang, wild oats, and reeds. The weeds are hard to fall and the seeds fall into the soil and become the source of weeds for the second year. Chemical weeding is an important control technology in places where Hexi has more land. 1.Before sowing, use 48-50 ml of 48% trifluralin per acre (low dose of coarse particles, high dose of fine particles), or 70% of aprotinin 200-400 ml of water. Soil surface spray, soil mixing in time after application, and strive to mix the soil. After soaking with trifluralin, sow 7 to 10 days after sowing the mixture. 2. After seedling, treat 200-300 ml of emulsifiable concentrate per acre with 20% of tetraammine (also known as amine fluoride), or spray 400-500 ml of 20% oxaphanine EC. Immediately after spraying, the soil is lightly mixed. E-oxaprop is effective when the soil moisture is high. 3. Post-emergence shoots and leaves treatment In the 2-5 leaf stage of grass weeds, use 10% locust EC per acre 70-100 ml, or 35% of a stable kill EC 130 ml, and 20% flutter 120-130 ml net emulsion, spray 30-40 kg evenly weed. In the past two years, there has been a vicious weed in Wuqin Minqin and other places. It deserves high attention. The seed of this weed is very small, and each seed produces a large amount of seed, which easily adheres to sunflower seeds and spreads as the seeds are transported. The field can also be transmitted by means of wind, currents, and human and animal activities. Therefore, the sunflower seeds used must be rinsed and the manure must be thoroughly cooked. In addition, no areas have yet to be regulated from the affected areas. SARS-CoV-2 Neutralizing Antibody Test Cassette SARS-CoV-2 Neutralizing antibody Test Cassette NINGBO AUTRENDS INTERNATIONAL TRADE CO., LTD , https://www.metests.com