1, nicosulfuron
Nicosulfuron is the most widely used herbicide in corn field at present, and this herbicide, such as crabgrass and green bristlegrass, has good effect. A "safe" nicosulfuron appeared in early years, claiming that 2-9 leaves of corn can be used, while the traditional nicosulfuron is used in 3-5 leaves of corn. Despite the manufacturer's publicity, there have been some drug injuries, so it is necessary to be cautious when using them. Sweet corn and popcorn are forbidden.
2, mesotrione
Mesotrione is relatively safe for corn and can be used in general sweet corn. Popping corn and ornamental corn should be cautious, and be careful of phytotoxicity. The effect of mesotrione on Portulaca oleracea and Setaria viridis is very poor, and it is not effective on older weeds, so it is recommended to apply it early. The effect of mesotrione is better in the south where soil moisture is better, but it is not good in the north where there is little rain, and the use cost is higher than that of nicosulfuron.
3. Benzoxadiazine
BASF patented compound, 2018 65438+1October 8, the patent protection has expired. Many domestic manufacturers have been following up, and it is one of the safest herbicides in corn fields, which is safe for sweet corn. This herbicide has high activity and good miscibility. A herbicide can control many kinds of weeds, but its control effect on sedge is poor. At present, it is rarely used in South China, probably because of the high use cost, and the sales volume is expected to increase after localization.
Matters needing attention in weeding corn seedlings
1, 7 days before and after spraying herbicides, it is forbidden to spray organophosphorus pesticides, otherwise it will easily cause phytotoxicity. Corn seedlings treated with organophosphorus pesticides are sensitive to herbicides, and the interval between them is at least 7 days. It can be mixed with pyrethroid insecticides, and attention should be paid to avoiding the heart leaves as much as possible when spraying, so as to avoid filling the heart with liquid medicine.
2, according to the prescribed dose for continuous spraying, don't arbitrarily increase the dose. Using the "secondary dilution method", the mother liquor is prepared first, and then the water is sprayed evenly. The drug effect is good after 6 pm, and continuous high temperature weather is avoided.
3. Before using herbicides, pay attention to cleaning the sprayer sprayed with organophosphorus pesticides. When using a motorized sprayer, the dosage shall not be increased without authorization, and repeated spraying is prohibited.
The above contents refer to Baidu Encyclopedia-Nicosulfuron.