The Indiana Pesticide Review Board voted unanimously at their Aug. 30 meeting to make all herbicides containing more than 6.5 percent dicamba restricted-use in Indiana.
This means that only trained and certified applicators will be able to purchase and apply products that contain dicamba. Applicators will need to purchase dicamba herbicides from registered restricted-use pesticide (RUP) dealers. Both sellers and applicators will need to keep detailed records on any dicamba they handle, which will be used by the Office of Indiana State Chemist to track drift complaints and ensure that the product is being used safely.
This decision was mainly influenced by the large number of complaints that have been filed with the OISC about drift of the highly active herbicide ingredient, which can result in damage to non-tolerant crops. As of Sept. 18, the OISC had received 254 total drift complaints for 2017, and 126 of those complaints are alleged to involve a dicamba herbicide.
"In a significant drift year, we usually average maybe 100 complaints, if that, for drift of all types—not just in agriculture," said Dave Scott, pesticide administrator with the OISC. "One hundred is a high annual average number for us, and we are well over 100 just for dicamba. It's been a significant issue for us and other states as well."
U.S. EPA currently recognizes three dicamba herbicides for use on tolerant soybeans, all of which will now be considered RUP's in Indiana: BASF's Engenia Herbicide, Monsanto's XtendiMax and DuPont's FeXapan. Older formulations containing dicamba will also be restricted.
"The board has proposed to make all agricultural-use dicamba products—anything over 6.5 percent—restricted because we already learned in 2016 that even though there weren't any dicamba-containing products registered for legal use on soybeans, that didn't stop applicators from going out and using the old formulations," said Scott. "Those products are more volatile than the new formulations, and theoretically more difficult to control."
The OISC will monitor herbicide dealers and distributors to ensure that older dicamba products are not being diverted to soybean growers for illegal use. The Indiana Pesticide Review Board and OISC urges growers, applicators and distributors to work together to successfully introduce this new weed management option while ensuring the safety of non-tolerant crops.
"This is not just an issue in Indiana," said Scott. "It's an issue in every state that uses this product. We are trying to coordinate with agencies in other states, as well as with EPA, cooperative Extension services, weed scientists and users of the product, as well as with Monsanto and BASF."
Representatives from Monsanto and BASF att-
ended the Aug. 30 pesticide review board meeting and did not speak out against the rule change. The rule awaits review by the attorney general this week. After approval, the governor's signature and publication in the Indiana Register are the final steps before the rule goes into effect.
The OISC maintains a fluid website that is updated daily. Visit the Dicamba Herbicide Updates page for more information as well as guidelines for filing a drift complaint.