New dicamba-related research coupled with some 900 drift complaints in the state led to an additional field day at the Northeast Research and Extension Center in Keiser, Ark., on Aug. 15. A week earlier, trailers were full of attendees and the follow-up was also well-attended.
Also in the research plot touring mix: a governor-appointed task force currently coming up with a game plan for the future of dicamba-tolerant crops in Arkansas.
Bob Scott, University of Arkansas weed scientist, has helmed the stop highlighting technologies in the pipeline.
“I’ve been talking at the HT3 soybean stop, a triple-stack soybean that’s just like Xtend cotton. It’ll tolerate Roundup, Liberty and dicamba. Monsanto gave us permission to show this soybean during the field day.
“There’s a hopeful release date of 2019 for seed. It looks good.
“There are a lot of different combinations of herbicides, different combinations of Liberty and XtendiMax or XtendiMax Plus doing a good job on pigweeds in our trials. So, that’s good news.”
Another soybean technology that’s coming is Balance GT, “the Balance bean, from Bayer. There’s also MGI beans from Syngenta and the Enlist technology from Dow.
“We’re hearing 2019 is also the target release date for the Balance GT soybean, which is a HPPD/Liberty stack.”
The Enlist soybean is ready to go. “It’s labeled in the United States but, for some reason, has been held up by China. So, that technology is kind of an ‘any day now’ for release. The cotton and corn versions of that technology have already been introduced.”
The Enlist technology was recently licensed to Syngenta. “That’s interesting because Syngenta is now owned by the Chinese government. That would seem to put an impetus behind the Chinese approving the soybeans.
“The MGI soybeans, another HPPD- and glufosinate-tolerant technology from Syngenta, is expected to be ready in 2020. It’ll most likely be stacked with either dicamba or 2,4-D.”
How might the new technologies figure into the current problems with dicamba?
“None of these new technologies will change the fact that we’re dealing with a volatile herbicide in dicamba. Obviously, if there’s widespread adoption of the HT3 bean or if one of the new HPPD beans come out and are also dicamba-tolerant, you’ll see a decrease in drift complaints on beans.
“However, none of the technologies, again, will address the use of any of the dicamba formulations we’ve been talking about. With the HPPD-tolerant bean and Enlist-tolerance you could see a decrease in the use of Engenia and XtendiMax. Obviously, if you put out less of those products you’ll probably hear fewer off-target complaints.
“One concern we have with the Enlist technology – 2,4-D choline – it’s been shown to be lower volatility. But until we get it out in the field – like we did with Clarity, this year – and load up a significant portion of the environment in the state, we don’t really know how well it’ll stay put. How safe will it be around cotton? We know it can be used safely around soybeans. But everyone knows how sensitive cotton is to 2,4-D.
“If there’s a triple-stack, guys who haven’t used the Engenia Xtend beans because of the buffers may try the new technology. That way they can spray Liberty in their buffers. That could sway a few more producers to have the dicamba-tolerant beans in their program.”
A day earlier, during the task force tour, “we were directly asked ‘what can we do to make (new dicamba formulations) safe to use?’ Based on what we’ve seen out here, it’s rough going. I told them ‘we need a new, better formulation of dicamba that’s truly non-volatile.’
“One of the things we’ve observed here is we made an application of both XtendiMax and Engenia on 3.5-acre blocks. A 3-mile-per-hour-wind was blowing out of the west for the first six hours after application – lo and behold, there was a drift plume that went west. It actually traveled farther than the 110-foot buffer currently mandated.”
What was really unexpected, says Scott, “was when, from 24 to 36 hours following application the wind shifted from the south. A drift plume to the north then showed up. If you think about that, the only way that plume to the north could have happened is if there was volatility after the application 24 hours, or more, after spraying.
“Based on that, there’s no buffer, no recommendation I can make with confidence. So, we need a new formulation as a sure-fire way to deal with these drift problems.
“Yeah, we could grow 100 percent dicamba-tolerant crops. But that won’t address the off-target problems we’re seeing in trees, in homeowner’s gardens, landscaping, those types of situations.”