Does managing waterhemp take more than herbicides?

As crops progress through their grain fill stages, this is usually the time when we can reflect on the weed control programs that were used for the year. Overall, layered residual programs in both corn and soybeans have better overall control at the end of the season. Sometimes even the best programs will have escapes due to lack of activating rain or timing of application.

Multi-Year Waterhemp Control Strategy: Why It Matters 

To have a successful waterhemp control strategy, it is important to think about our chemical programs over a multiple year span. Poor weed control in corn (especially with waterhemp) can lead to increased weed pressure in our soybeans the following year. While many growers may do a great job with their chemistry plan for soybeans, did the corn results look the same?

Layering Residual Herbicides in Corn: The Key to Cleaner Fields

Layered residual herbicide programs in corn, like Verdict^® herbicide followed by Armezon^® PRO herbicide, have consistently provided cleaner fields than 1-pass programs.

📸: BASF employee/Featuring late emerged waterhemp in corn.

Waterhemp's Achilles' Heel: How Its Seed Bank Can Be Your Advantage 

Herbicides continue to be the most convenient and arguably the most cost-effective way to manage waterhemp in corn and soybeans. By understanding some of the weaknesses of waterhemp, we can also use other tactics to reduce weed pressure over several years. One of the largest weaknesses of waterhemp is its lack of longevity in the soil. After 3–4 years, the viability of waterhemp seed dramatically declines in the soil (with less than 5% of the original seed able to germinate). This means that limiting seed production of waterhemp can be a viable option for reducing weed pressure in future years.

📸: BASF employee/Featuring waterhemp growing on field edges.

Beyond Herbicides: Alternative Tactics to Manage Waterhemp 

While not all of these alternative tactics may fit your operation, some options have been shown to reduce waterhemp populations over time. Tillage, where possible, can bury waterhemp seed at depths that reduce germination. Narrow row spacing in soybeans can reduce the amount of time that waterhemp can germinate in fields due to faster canopy closure.

Don't Let Up: Strategies for Tough-to-Control Waterhemp Areas

Managing tough-to-control areas like field edges, drown-out areas, or sprayer skips. This may require mowing prior to seed head development in waterhemp or spot spraying where possible. Lastly, hand roguing crews have been successful in removing escapes prior to seed set, thus reducing future potential for waterhemp pressure. 

The Power of Combining Tactics: Why Herbicides Still Play a Role

As mentioned, chemical control is still a viable option. But for fields where growers continue to fight heavy pressure with waterhemp, additional tactics may need to be added to the overall plan in the fight against waterhemp.

Before mixing components, always conduct a compatibility jar test. Always consult respective product labels for specific mixing instructions. The most restrictive label applies.

Always read and follow label directions. Grow Smart, Verdict, and Armezon are registered trademarks of BASF. Copyright 2024 BASF Corporation. All rights reserved.