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Agronomic Crops Network

Ohio State University Extension


Reminders about dicamba

This is the time of year when we received our first call about dicamba problems in soybeans in 2017.  We can probably expect any problems to become evident soon, based on the timing of postemergence applications and timeline for development of symptoms.  Off-target issues have already developed in states farther west and south, and we would expect at least some to occur here, unless we’re really lucky. The symptoms of dicamba injury show in new soybean growth within approximately 7 to 21 days after exposure, and most of our soybeans receive postemergence applications from early June on.  It’s been a challenging year to properly steward postemergence applications.  We still face some challenges in finding appropriate weather to catch weeds before they become too large, and before soybeans are too advanced in growth stage.  There are a number of weather, application and adjacent crop factors to consider when applying dicamba, and applicators should review labels as frequently as needed to ensure legal application. 

We have two requests relative to reporting of off-target dicamba issues.  First, we ask that if at all possible, they be reported to ODA.  It is important for ODA to have a record of these, in order to be able to make sound decisions on mitigating risk from dicamba as we move forward, or decide that no additional mitigation is necessary.  Reporting to ODA allows them to be able to investigate the cause of off-target issues, and develop first-hand knowledge that can aid in making these decisions.  As we ask this, know that we are fully aware of the reasons why off-target injury issues are not reported to ODA.  The companies involved are once again at least talking a good game about investigating dicamba issues that are reported to them, and we would certainly encourage reporting any incidents to them also.  Experience in 2017 would indicate that for at least one company, on-site investigations occurred only if reported by the party who purchased and applied the dicamba product.  Reporting only by the affected party did not warrant the same level of investigation.  Maybe this has changed.

The second request concerns how OSU Extension staff and clientele communicate anything pertaining to off-target dicamba problems to OSU Weed Science, including Mark Loux.  Due to litigation on dicamba occurring somewhere beside Ohio, OSU has been subject to an open records request asking us to provide files we have related to our experience with dicamba – off-target investigations, research, etc.  First time in my career this has occurred.  In addition to the time we will have to put in to deal with this, there’s just the general hassle of it all.  There is also another aspect - we cannot necessarily protect the confidentiality of anyone sending emails to us.  My specific request is this – from this point on please do not send anything in written or electronic form to us about dicamba, including emails, photos, etc. Should you need to contact us about a dicamba issue, please feel free to call.  We still want to provide information and service on this issue, and are certainly not trying to shut off communication.  Moving forward, we are just trying to avoid maintaining any type of records that could be asked for in this type of request.  Fun times to be an extension weed specialist. 

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.