The dicamba system, approved for use for the first time this spring, was supposed to break the cycle and guarantee weed control in soybeans and cotton. The herbicide — used in combination with a genetically modified dicamba-resistant soybean — promises better control of unwanted plants such as pigweed, which has become resistant to common weed killers.
The problem, farmers and weed scientists say, is that dicamba has drifted from the fields where it was sprayed, damaging millions of acres of unprotected soybeans and other crops in what some are calling a man-made disaster. Critics say that the herbicide was approved by federal officials without enough data, particularly on the critical question of whether it could drift off target.
Government officials and manufacturers Monsanto and BASF deny the charge, saying the system worked as Congress designed it.
Continue reading: Weed killer designed to save farms is devastating them