Persistence of imazethapyr in two Atlantic Canada soils

The acid-imidazolinine herbicide imazethapyr is now used for weed control in soybeans, and shows promise for use in other legume crops. Its half-life was measured in two soil samples from Atlantic Canada, and was found to range from 19 to 63 days. Persistence was extended through soil incorporation, but the limit of detection was reached within 120 days after the application of 75 g per ha. This level of application did not affect sensitive crops in rotation up to one year after application.