Home 5 Ag Stories Weed specialist fears modified dicamba label is not enough

Weed specialist fears modified dicamba label is not enough

A federal agency has granted continued registration for a weed control technology.

The extended approval came a few adjustments. However, an Iowa weed specialist believes the recent changes are not enough to prevent further injury.

AUDIO: Bob Hartzler, Iowa State University Extension

Environmental Protection Agency Acting Administrator Andrew Wheeler on Wednesday announced the continued registration of the XtendiMax® herbicide with VaporGrip® technology. The two-year extension with new label restrictions intends to “provide certainty for all stakeholders ahead of the upcoming growing season.”

However, Iowa State University Extension and Outreach weed specialist Bob Hartzler is skeptical about the recent changes. Hartzler says he was “a little disappointed” by the recent changes.

“Unfortunately, I’m not real optimistic,” Hartzler said. “Dicamba moves in various ways – partial drift, volatility and sometimes runoff. But volatility is the wild card, in that the applicator can apply the product perfectly, but conditions could favor volatility, which generally is high temperatures. If volatility is an issue, these restrictions do nothing to limit that.”

Among the biggest changes made to the label include restrictions on application timing.

“Previously, dicamba could be applied on Xtend® soybeans up to and through the R1 stage. Now it needs to be applied prior to the R1 stage. Most years, that would be a three- to five-day difference, so not that big of a difference,” Hartzler said. 

“They also put a 45-day after planting restriction on,” Hartzler said. “Where that would come into play, I suppose, (is) on early planted beans that don’t develop very quickly in the first three weeks or so. That 45 days might come earlier than when people want to apply the product,” Hartzler said.

Overall, Hartzler believes these changes will not have a big impact on application timing. He feels a need for further adjustments, to restrict applications from causing off-target injury.