There are many reasons why weeds rebound after using herbicides ① When using herbicides, the temperature is too low after application, or the soil is dry. ② The dosage of herbicide is too small or the amount of water used is too small and the spraying is uneven. ③ When the grass is too old when applying pesticides, the weeds will become more resistant to pesticides and cause rebound. ④The herbicidal spectrum of the herbicide used does not match the local grass species. ⑤ When spraying herbicides, other pesticides may cause antagonistic effects. Based on the question you asked, I personally think your situation is related to ④. For wheat fields dominated by Artemisia somnifera, it is recommended to use bensulfuron+trimethafil+flumetrazone before wheat jointing next year, or dimethyltetrachloride (consult local dealers for usage technology)+flumetrazone + Bensulfuron has good control effect and can also control other broad-leaf weeds. As for the problem you mentioned about Qingdao Nongguan Snow Tiger. Personal suggestion: You can try Qingdao Nongguan's Snow Tiger on a small area (16% flusulam-clofenac suspension). The manufacturer claims: It contains an independent patented antibacterial agent, which can be used from the green stage to the flag-raising stage, and has a significant effect on the older wormwood and shepherd's purse. Our local area is also conducting experiments on a small area to accumulate experience. For the time being, the safety and effect are good. After 8 days of application, it has obvious control effects on the older wormwood and shepherd's purse (not blooming). It has not completely dried up and died, and the effect is still under observation.