Crossresistance in chlorsulfuronresistant chickweed (<i>Stellaria media</i>)

Abstract

In New Zealand chlorsulfuronresistant chickweed was discovered in 1995 Experiments were conducted in the field and glasshouse to determine whether these resistant plants were also cross and multipleresistant to other herbicides normally effective on chickweed A population of chlorsulfuronresistant chickweed growing in an oat crop near Winton in the South Island was treated with 13 different herbicides This population was not controlled by mecoprop methabenzthiazuron and pendimethalin and only partially controlled by bromoxynil ioxynil diflufenican isoproturon and diflufenican bromoxynil in the field trial Two followup glasshouse experiments using plants grown from seeds harvested from the surviving plants confirmed crossresistance to thifensulfuron and susceptibility to all the other herbicides including tribenuron