At first glance, there are many similarities between the XtendFlex® and Enlist E3® soybean systems. Each have restrictions on nozzle selections, tank-mix partners, adjuvants, wind speed and sensitive crops. However, each system’s specific restrictions require tailored approaches to achieve success. In fact, knowing the differences in allowed tank-mix adjuvants is something I often see confusing growers. So, let’s take a close look at each one and discuss strategies for a successful season. 

XtendFlex Soybeans

The latest dicamba label changes are top of mind for XtendFlex growers this season. The label now requires a volatility reducing agent (VRA) to be included in every dicamba tank mix. VRAs are pH modifiers that keep the pH of the spray tank high enough to prevent the dicamba from reverting back to a volatile form to prevent off-target movement. Volt-Edge™, a VaporGrip® Xtra agent, for example, buffers solution pH to help reduce free protons that can lead to volatility. Before adding this to your tank mix, always check the manufacturers’ websites for recent tank-mix approvals. A separate, approved drift reducing agent (DRA), such as OnTarget®, must also be included with some tank mixes.
 
When there is a DRA in the tank that thickens the solution and increases droplet size, I also recommend adding 2 oz./acre of InterLock®, a drift reduction technology. Large droplets can be counterproductive and negatively impact efficacy. When droplets are too large, they run the risk of hitting the leaf surface at such a high velocity that they bounce off and end up on the ground. Adding InterLock to a DRA helps moderate the droplet size for better coverage and reduces the number of driftable fines.
 
Water conditioners are another important addition to the tank. They help tie up cations in water so negatively charged herbicide particles don’t bind to them, which can reduce herbicide effectiveness. For the XtendFlex system, an ammonium sulfate-free water conditioner specifically formulated for dicamba like Class Act® Ridion® is a great choice. 
 
XtendFlex growers should also keep a close eye on other dicamba label requirements, such as the June 30 application cutoff date, required training for applicators, wind speed and time of day restrictions.

• Wind speed: Between 3 mph and 10 mph.
• Time of day: Between one hour after sunrise to two hours before sunset. 

Prescribing a tank mix for your XtendFlex system can be complicated and nuanced. Below are my top recommendations for the XtendFlex system but, as always, be sure to confirm recent tank-mix approvals.

• Good: Valcheck® II + Volt-Edge
• Better: OPTIFY XX + Volt-Edge + InterLock
• Best: ClassAct Ridion + OnTarget + Volt-Edge + InterLock

Enlist E3 Soybeans

With Enlist, droplet size is especially important. When spraying Roundup®, larger droplets are less of a concern because it’s a systemic herbicide. When spraying Liberty®, however, coverage is critical because it works on contact. To improve coverage, increase gallons per acre and choose an approved nozzle that outputs smaller droplets. I know it can be tempting to use the same nozzle on every system, but it’s important to match the droplet size with the chemistry.
 
Choosing a tank mix for the Enlist system isn’t quite as straight forward as the XtendFlex system because there are more variables to consider. Recommendations will differ depending on whether the tank mix is going out with glyphosate and or glufosinate.

Coverage and Spray Pressure

With both systems, you’re restricted to running 24 inches above target with the boom. Any time a thickener is a part of the tank mix, the spray pattern narrows. Since you can’t raise the boom height to combat that, I recommend running at the higher end of recommended pressure ranges to keep spray patterns as full as possible. This adjustment will help prevent streaks in the field and ensure even coverage across the entire spray boom. Increasing pressure also helps you reduce droplet size, another important factor for good coverage.

Weed Management Best Practices 

Regardless of the trait package you’re using, weed management basics stay the same. Here are a few reminders:

• Be sure to use full rates of pre-emergence herbicides and overlapping residuals.
• Scout early and often.
• Spray weeds when they’re small. 

Whether you’re planting XtendFlex, Enlist E3 or some of both trait packages, your local WinField United retailer is available to help you plan your weed management strategy and navigate product selections. 

All photos are either the property of WinField United or used with permission.

© 2021 WinField United. Important: Before use always read and follow label instructions. Crop performance is dependent on several factors many of which are beyond the control of WinField United, including without limitation, soil type, pest pressures, agronomic practices and weather conditions. Growers are encouraged to consider data from multiple locations, over multiple years, and be mindful of how such agronomic conditions could impact results. Volt-Edge, VaporGrip, OnTarget, OPTIFY, Valcheck, InterLock, Class Act, Ridion and WinField are trademarks of WinField United All other trademarks are the property of their respective owners.