The Iowa Department of Agriculture and Land Stewardship (IDALS) reminds farmers that over-the-top application of dicamba on soybeans is prohibited after June 20 in Iowa.
The Environmental Protection Agency (EPA) ap­proved a label amendment in March with the earlier deadline to reduce the risk of off-site movement of the dicamba products. The June 20 cut-off date, which is 10 days earlier than the 2021 growing season, was submitted by registrants for EPA review in January. Affected products include Engenia by BASF, Tavium by Syngenta and XtendiMax by Bayer.

Iowa Agriculture Secretary Mike Naig said the department is working with stakeholders to raise awareness and ensure dicamba application protocols are followed so farmers can maintain access to needed weed control technologies.

“The rise in litigation targeting pesticide product registrations and off-target pesticide misuse complaints pose a threat to farmers’ long-term access to dicamba,” said Naig.

In a review of dicamba-related incidents during the 2021 growing season, the EPA noted that Iowa and Minnesota had high numbers of off-target dicamba injury reports despite new control measures implemented after the 2020 growing season.  

The agency said it received approximately 3,500 dicamba-related incident reports nationwide during the 2021 growing season, including approximately 711 incidents reported in Minnesota and 528 incidents reported in Iowa.

AFBF, ag groups question data
The American Farm Bureau Federation (AFBF) and other ag groups questioned the accuracy of the EPA’s data, noting that the report wasn’t clear whether complaints were submitted to multiple sources and were therefore double counted.

The groups said it was also unclear whether complaints were investigated to verify injury or assess potential causes.

IDALS reports that it conducted 223 investigations related to misuse of growth regulator herbicides, including dicamba, in each of 2020 and 2021.

While significantly lower than the numbers reported by the EPA, IDALS' investigations were up from 128 such cases in 2019, the agency reported. In 2013, IDALS conducted 125 total pesticide misuse investigations with 39 of those related to growth regulators.