Thomas Robinson | July 21st, 2020
An Iowa State University scientist says that 2020’s crop injury from dicamba exposure has been the most widespread since the pesticide’s introduction in the 1960s.
A recent blog post by Iowa State University professor Bob Hartzler describes the likely reasons behind the unusually high amounts of dicamba damage seen in 2020. Agronomists across Iowa have observed extensive dicamba damage to non-resistant soybeans which can compromise the crop entirely. Dicamba is a commonly applied pesticide that is increasingly used to address weeds that have become resistant to other groups of pesticides. Unfortunately, dicamba is volatile and can form drifting clouds which can result in damage to nearby crops like soybeans which are sensitive to the pesticide.
The first factor which led to high dicamba damage is that the 9th U.S. circuit court of appeals ruled the EPA had understated the risks of dicamba application to crops creating uncertainty for the future use of dicamba products. The second factor was that poor environmental conditions for dicamba application were prevalent during June when the pesticide needed to be applied. High wind speeds and heat can allow the pesticide to volatilize and early June had limited times when conditions were right. These two factors likely led to dicamba applications in non-ideal conditions that resulted in extensive volatilization and damage to crops.
Crop injury from dicamba has been found in many areas of the Midwest where the pesticide is applied and concerns about the pesticide’s safety have been growing in recent years. Crop damage can result in agricultural losses for farmers and disputes over the pesticide have even escalated to murder.