Dicamba herbicide technology is not working well in southern states. This spring the state of Arkansas stopped the use of the technology because of offsite drift problems. Bill Johnson, extension weed specialist at Purdue, says that in Indiana there have not been any serious issues so far, despite weather conditions that have been less than favorable. “We had had many days with high winds and I was very nervous about the use of Dicamba during these windy days,” he states. “But, so far, there have not been any major problems. I checked with the State Chemists office this week and they had no reports.”
Johnson told HAT that farmers need to adjust their expectations for dicamba, “This is not the second coming of Roundup Ready. It is simply not the silver bullet that Roundup was in the 1990s.” He added they also need to adjust their weed management practices, “These herbicides are not really designed to be sprayed on large weeds. Eight inches is about the largest weed we can expect to control with this technology. While Dicamba is very good on giant ragweed, it had only average control on marestail, waterhemp, or palmer.” Another challenge for growers is managing the downside buffer restrictions. “We have a lot of houses in rural Indiana, so it is not just other crops but homeowners that can be impacted by spray drift,” Johnson said.
Manufacturers of Dicamba products are scrambling to address the negative publicity and problems with applications. One of the keys to proper Dicamba use is reading the label carefully — not only the label, but the web site as well. Ty Whitten, North America Crop Protection Systems Lead, Monsanto, says, “rounupreadyextend.com, is the best place to go for information.” He added that, in addition to reading the label, growers must check a web site within 7 days of application for the latest label changes as well as tips for application and use. That site is: www.extendamaxapplicationrequirements.com.