There’s much confusion over what dicamba-containing products can be applied as a burndown application before planting Xtend soybeans as a means of controlling resistant weeds. Here’s the “clear on it” from Dwight Lingenfelter and Bill Curran, Extension weed specialists at Penn State University.
“We have received calls inquiring about using certain dicamba products (Clarity, Banvel, etc.) as preplant applications ahead of planting Roundup Ready 2 Xtend soybeans,” says Lingenfelter. “Specifically, could Clarity, for example, can be sprayed in the burndown mixture, then immediately plant Xtend soybeans? The answer is no.”
Product labels for Clarity, Banvel and most other post-patent dicamba-containing products essentially state that at least 28 days plus 1 inch of rainfall/irrigation is necessary before any soybean is planted if 1 pint of product is applied. Since Xtend soybeans aren’t specified on their labels, this longer wait period must be applied.
Where, when and what can be used
Currently, the only dicamba products that can be legally applied near planting or over-the-top in Xtend soybeans are Engenia (BASF), FeXapan plus Vapor Grip Technology (DuPont) and Xtendimax with Vapor Grip Technology (Monsanto).
Also, before any application can be made, all of the guidelines must be followed to reduce off-target spray drift to other crops. It’s a significant concern, stress Curran and Lingenfelter.
To reduce drift and the other negative impacts to nontarget areas, these labels and associated websites list what herbicides can be tank-mixed with these products. Other mandated guidelines include prescribed nozzle types, boom heights, sprayer speed and wind speed limits.
Also, depending on the landscape setting, field buffers must be included if susceptible crops are present and downwind at the time of application. Guidelines for using Xtendimax, Engenia and FeXapan can change periodically as new information is acquired. Refer to the Monsanto, BASF and DuPont labels and websites for additional information and updates.
Got more questions? Email Lingenfelter at [email protected].
For more on these products, read Take this spraying quiz for controlling resistant weeds or see Page 8 in April’s American Agriculturist.
Source: Penn State Field Crop Newsletter