Safe Dicamba Use Remains Key for Growers

By Scout Nelson

South Dakota soybean growers are being reminded that over-the-top (OTT) dicamba herbicides labeled for soybean can only be applied until June 30, 2026, or until the crop reaches the R1 growth stage, whichever comes first. Farmers who miss the deadline should not apply dicamba products because doing so is illegal and may result in serious consequences.

Information shared by Eric Jones, Assistant Professor and SDSU Extension Weed Management Specialist, along with Philip Rozeboom, Jill Alms, and David Vos, highlights the importance of following label requirements and using safe weed control practices throughout the growing season.

Soybean planting began early across much of South Dakota this year. However, cooler temperatures and dry conditions slowed crop growth during the early part of the season. More recent rainfall and warmer temperatures have improved growing conditions for soybeans, but these same conditions also encourage weed growth.

For the 2026 growing season, dicamba products such as Engenia, Tavium, and Stryax remain available for use in approved soybean systems. However, these products must be applied before June 30, 2026, or before soybeans reach the R1 growth stage.

Before spraying dicamba, growers should carefully check weather conditions. Recommended conditions include temperatures below 80° F, wind speeds between 5 and 10 miles per hour, and the absence of temperature inversions. These conditions help reduce the risk of herbicide movement to nearby fields and sensitive crops.

Although volatility reduction agents and drift reduction products are required with dicamba applications, good weather conditions remain essential for safe use. Farmers can use weather monitoring resources to help determine the best application timing.

Experts also encourage mixing dicamba with other approved herbicides to improve weed control and reduce the risk of herbicide-resistant weeds developing. Growers should always review product labels because some tank-mix restrictions apply. For example, glyphosate and glufosinate products may be used with dicamba, but ammonium sulfate should not be included in the spray mixture.

After the cutoff date, farmers still have several weed management options. Other labeled herbicides, along with nonchemical practices such as cultivation, mowing, and hand weeding, can help control weeds and support an effective season-long management plan.

Photo Credit: istock-fotokostic