Synergism of six spray adjuvants on mesotrione in controlling Echinochloa crus-galli and Amaranthus retroflexus

The enhancement effects of six spray adjuvants with different concentrations on mesotrione in controlling Echinochloa crus-galli and Amaranthus retroflexus were investigated under greenhouse conditions, and meanwhile the relationship between critical micelle concentration(CMC) of adjuvants and the herbicidal effect of mesotrione were explored. On the other hand, the mechanism of the enhancement effects of spray adjuvants on mesotrione were analyzed from the point of the contact angle and maximum retention of pesticide solutions on the plant leaves. Results showed that all the six adjuvants with the concentrations above CMC could differently enhance the herbicidal effect of mesotrione by decreasing the contact angle and increasing the maximum retention, and had a better effect on controlling E.crus-galli. GY-Tmax and S903 had the best effect, while GY-T12 and QS-304 was better, the OP-10 and S625 had a general performance.