As farmers adopt dicamba-tolerant varieties of soybeans, there are fewer complaints of damage by the herbicide in soybean fields. But reports from 15 state departments of agriculture still indicate 383,840 acres of soybeans were damaged by dicamba this growing season. In addition, incidents of “off-target” movement of dicamba to specialty crops, vegetables, ornamental species and trees “seems to be more prevalant this year compared to last season,” says a University of Missouri weed specialist Kevin Bradley.
Among the 15 states, 154 cases were under investigation of which 43 involved soybeans. In southeastern Missouri, many growers shifted to soybeans genetically modified to withstand dicamba “so they don’t experience dicamba injury on their soybean crop for the third season in a row,” wrote Bradley. As a result, fewer fields exhibit damage but “there are still fields of (unprotected) soybeans in this area showing damage from one end to the other.”
“More surprising to me than that has been the extent of trees that are showing symptoms of growth-regulator herbicide injury in that part of the state where the adoption of the (dicambe-tolerant) trait is so high,” said Bradley.
The states with the largest number of acres of soybeans affected by dicamba damage were Illinois with 150,000 acres, followed by Arkansas and Mississippi with 100,000 acres each, and Missouri with 25,000 acres.