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Take note of dicamba changes for 2021

Most row-crop growers have now heard that dicamba products XtendiMax with VaporGrip, Enge­nia, and Tavium with VaporGrip have been given a five-year label going into 2021. This is great news and a much-needed addition to weed-control options. Additionally, Bayer released XtendFlex soybeans for the 2021 growing season. This technology allows for the over-the-top application of glyphosate, dicamba and glufosinate (Liberty) to XtendFlex soybeans.

Note that glufosinate and dicam­ba products cannot be tank mixed together. Glufosinate requires ammonium sulfate (AMS) to work properly, and new dicamba prod­ucts cannot come into contact with AMS. Strict cleanout requirements need to be followed when switching from a dicamba product to glufos­inate or vice versa on XtendFlex soybeans to ensure these dicamba products do not contact AMS.

Farmers need to be aware of some changes that have been made to the previous labels of Xtendi­Max, Engenia and Tavium going forward. First, note that June 30 is the national cutoff date for dicamba applications over soybeans, and July 30 is the national cutoff date for post-emergent cotton applications. These products can be applied up to and including those cutoff days.

MFA will once again monitor growth stages through its Sentinel Plot network in which multiple fields in different regions of our ter­ritory are scouted each week. Once flowering begins—the R1 stage—post-emergent dicamba applications are stopped in that region. With this protocol, some areas of our territory could see a cutoff at varying dates prior to the national deadline. We will continue this system and issue cutoff dates prior to June 30 or July 30 if necessary.

Another change to dicamba use is extended buffer zones. Downwind buffer zones have increased from 110 feet to 240 feet from the last treated row and the nearest down­wind field edge. The zones include roads, paved or gravel surfaces, mowed grassy areas adjacent to field, and areas of bare ground from recent plowing or grading that are contiguous with the treated field.

Perhaps a more important change to carefully note is the endangered species buffer zones. These have increased from 110 feet to 310 feet downwind PLUS a 57-foot omnidi­rectional buffer. There is no longer a list of counties designated as hav­ing endangered species. To know where endangered species areas are located, applicators will need to refer to EPA’s Bulletins Live! website before spraying. This live map can be updated whenever necessary: bulletins-live-two-view-bulletins.

The use of drift reduction technology such as hooded spray­ers may qualify an applicator for reduced buffer zones in soybeans. Specific drift reduction technolo­gy can be found at each product’s respective website.

Everyone is familiar with drift reduction agents (DRA), such as Impetro II, that must be added to dicamba tank mixes. However, in addition to the DRA, there is now a volatility reducing agent (VRA) that must be also be added to the tank mix. These VRAs are also called pH buffering agents, depending on the label. Vapex is a new approved VRA that MFA will be using with our dicamba mixes. Be sure to check your product’s respective label and website for approved VRAs specific to your product. XtendiMax, Enge­nia and Tavium all require a DRA and VRA for applications.

A change specific to XtendiMax is the maximum pre-emergence rate is 22 ounces per acre for a single application. Previously, an applica­tor could run 44 ounces per acre in a pre-emergence application. Now, there is a maximum of two applica­tions at 22 ounces per acre.

Runoff restrictions also have been updated. Previously, dicamba prod­ucts could not be applied if rainfall exceeding field capacity was expect­ed within 24 hours. That has been changed to 48 hours after applica­tion. So, if runoff is possible within 48 hours of application, dicamba products should not be applied.

Mandatory training and record-keeping are still required for all ap­plicators along with all other label restrictions listed for each product. The restrictions I have mentioned here are updates to the previous restrictions, and none of those has been removed. Make sure you con­sult the label specific to the product you plan to apply for all restrictions and information. Find the websites for each product in the box below.

The crop protection technologies at our disposal are great tools, but they also come with a great responsi­bility. I hope that we can use them responsibly, safely and according to all label restric­tions to ensure a successful 2021 season and beyond. 

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