By MICHELE F. MIHALJEVICH

Indiana Correspondent

WEST LAFAYETTE, Ind. — The pesticide administrator for the Office of Indiana State Chemist (OISC) is uncertain if changes the U.S. EPA has made to dicamba labeling will be enough to lower the number of drift complaints the state receives.

The EPA announced last month it is extending the registration of dicamba until Dec. 20, 2020. Included in the changes to the label is a requirement that only certified applicators may apply the herbicide over-the-top (OTT). Applications will only be allowed from one hour after sunrise to two hours before sunset.

The new label prohibits OTT application of dicamba on soybeans 45 days after planting. Enhanced tank clean-out instructions for the entire system are also included.

OISC is investigating 272 drift complaints from 2018, said David Scott, also secretary for the Indiana Pesticide Review Board. Of those, 143 are believed to involve dicamba. Last year, the agency conducted 270 drift investigations; 133 of those involved dicamba.

“I wasn’t surprised (EPA) made some tweaks,” he noted. “For two years in a row, we’ve had an unprecedented number of complaints associated with one active ingredient. I don’t know how anyone could call this, by any measure, business as usual. I don’t think (the labels) have been tweaked significantly.

“I don’t know why we would expect a different result in 2019 than we had in 2017 and 2018. Because I’m an optimist, I’m hoping for the best (in 2019), and I’m hoping the numbers are cut in half. I don’t know how the tweaks will help our numbers.”

The Illinois Department of Agriculture is “still reviewing the labels and additional requirements associated with dicamba that were recently issued by the U.S. EPA,” said Morgan Booth, the agency’s public information officer. In 2018, the state logged 330 alleged dicamba complaints, up from 246 in 2017. Enforcement action was taken in 167 of those cases last year.

Ohio, which had 26 dicamba complaints last year and 52 in 2018, is “still kind of parsing (the new label),” said Brett Gates, deputy communication director for the state Department of Agriculture. “With it being a restricted-use pesticide, we have to make sure we’ve got everything covered.”

The EPA’s decision to approve new labeling demonstrates a confidence in the technology, said Ryan Rubischko, dicamba portfolio lead for Bayer Crop Science, manufacturer of XtendiMax herbicide with VaporGrip.

“The label provides more clarity in how the technology should be used for successful results,” he added. “For example, sprayer hygiene – that can have some impact if done correctly.”

Bayer has worked with more than a dozen universities on research involving its dicamba product, Rubischko said. Volatility remains low when applicators follow the label.

“Growers have indicated the need for this important tool, as a component of a complete weed management system, to fight tough-to-control weeds,” Rubischko said. “XtendiMax is a highly effective, proven broadleaf weed control option that is delivering results for farmers, who have reported 95 percent weed control satisfaction over the last two seasons.”

In more than 70 percent of the drift investigations conducted by the OISC last year, officials were unable to determine how or why the dicamba moved off-target, noted Bryan Young, a professor of weed science at Purdue University.

“If you don’t know how it’s getting to certain areas, how can you write a label to protect against that? You have to understand how it’s moving. You have to look at conditions during and after application. You have to learn how did that occur, why did that occur,” he said.

Bob Hartzler, a professor of agronomy and extension weed specialist for Iowa State University, said the EPA is in a difficult position in regulating the technology.

“Whatever they do is going to be criticized by some people,” he pointed out. “Unfortunately, I don’t think these new restrictions will have a significant impact on the problems we’ve seen the last two years. I was hoping for something similar to what Minnesota did in 2018, a date and temperature cutoff for dicamba applications on Xtend soybean.”

Steve Smith, chair of the Save Our Crops Coalition, called the EPA’s decision unacceptable and disappointing.

“We were advocating for a pre-plant only label,” explained Smith, also director of agriculture with Elwood, Ind.-based Red Gold. “This wouldn’t have totally stopped all the issues, as some trees, orchards and vineyards would have already been leafed out, but it would have gone a long ways toward reducing the problems to a more manageable level.

“We were also advocating for a subsequent-year restriction to help avoid weed resistance that is bound to happen if the product is used on both corn and soybeans year-after-year.”