Pre-Emerge Applications are the “Best Recommendation”
Jan 24, 2022
In an unpredictable supply market, pre-emerge herbicides on soybeans can help protect yield potential by addressing critical factors:
- The weeds are already in the soil, waiting to compete for the sun, water, and nutrients the soybeans need. Pre-emerge herbicides “can reduce the weed seed bank in the soil,” said Craig Loen, Federated agronomist at the Osceola location.
- Weeds underground are “easier to terminate; they only have one growing point,” said Loen. Once they emerge – especially a resistant weed like waterhemp – the weeds have multiple growing points that make them harder to terminate or control.
- Small, germinating weeds can be eliminated by a good pre-emerge herbicide, and then, “the next flush of weeds will be similar in size, making the post application more effective,” he said.
- Resistant weeds (e.g., waterhemp and giant ragweed) have less chance of survival with a good pre-emergence herbicide plan.
- Timely application. Some pre-emerge herbicides need to be applied within three days of planting because the “bean seeds can’t be exposed,” said Loen. Row closure is critical; seeds can’t be cracking the surface of the soil. If the herbicide comes in contact with the seed, it can kill the germ.
- Effective layering of residual herbicides.
- Multiple modes of action.
- “Again,” said Loen, “multiple modes of action.” That is the best recommendation for controlling weeds in soybeans.
- More than one option. In a tight supply market, you may not be able to get your go-to per-emerge herbicide; you need a plan B. And the weather or schedules might frustrate plans further.