News

Research shows temp inversions suspect in dicamba drift

University of Missouri weed scientists are studying the potential effects of temperature inversions on off-target movement of the new dicamba-mix herbicides. MU Extension weed science specialist Kevin Bradley tells Brownfield Ag News the information they’ve gathered from weather stations they’ve set up in Missouri indicates the warmer air above is a contributing factor, “It just shows us that it is possible for these new products to escape out of the air as a gas and we have proven that already. To what extent that is causing the problem is something we need to learn throughout the rest of the summer and that’s what we’re going to try to do.”

Missouri’s ag director temporarily banned the sale and use of dicamba products late last week.

Bradley tells Brownfield their research shows that growers should not spray dicamba products at night, “To be safe, we probably ought to be spraying between 9 a.m. and 3 p.m. because our data says in that afternoon time-frame an inversion can set in. You know, the labels don’t require you to do that but I think that’s a safe thing that we can do that could help.”

Bradley says their research shows off target movement IS possible through volatility or temperature inversions and growers HAVE to follow labels, “For some reason, people don’t believe it until they see it that this stuff can be that bad at such a small dose. Just trust me, we don’t need to go there. We don’t – you don’t need to see it happen for yourself. It IS going to happen if you don’t follow those spray parameters that are on those labels.”

Bradley says most of the reported damage is in northern and southeastern Missouri affecting more than 200,000 acres of soybeans.

Missouri Ag Department director Chris Chinn says the companies that make the new products are working with her department to come up with state-use labels so the temporary ban can be lifted as soon as possible and she has been in consult with the university.

Bradley held a dicamba injury forum at the Pest Management Field Day at MU’s Bradford Research farms on Friday, July 7. A few hours later, Ag Director Chinn announced the temporary dicamba ban across the state of Missouri.

AUDIO:  Interview with Kevin Bradley