China recently tightened its restrictions on weed seed allowance, reducing it from 2% to 1% for all soybean imports. Soybeans are U.S. agriculture’s most valuable export. USDA responded by issuing grower and grain exporter guidelines to try to reduce weed seeds in U.S. soybean shipments.

“Growers will have to step up their weed management measures to ensure the soybeans they harvest aren’t going to get docked at the elevators,” says Dean Grossnickle, Syngenta agronomy service representative based in central Iowa.

Getting ahead of weeds
In a recent Iowa State University survey, less than 5% of growers and industry participants said herbicide resistance would not be a problem for their operations over the next few years. You can view the survey results online.

There are a few things growers can do to minimize weed pressure. Cultural practices such as crop rotation and tillage can both work as control methods. It’s even more effective to combine these approaches with a strong chemical weed management program, Grossnickle says.

Diversify weed management
When dealing with resistant weeds, a common misconception has been that one site of action is a sufficient solution for control. However, using a single SOA year after year will cause weeds to develop resistance to that technology.

“Many technologies are not going to stay effective year after year,” Grossnickle says. “Herbicide programs containing a single active ingredient are at risk of failing after just a couple of years, so the key to successful weed management is diversifying your program. This means overlapping residual herbicides containing multiple effective SOAs that directly target the weeds you’re dealing with.”

Devising plan of action
Choosing the right treatment involves identifying the weed populations confirmed in your fields and selecting a program containing herbicides with SOAs in which resistance has not yet developed. 

Growers should start their planting season with a burndown or preemergence herbicide application to limit the number of weeds from the outset, Grossnickle advises.

Syngenta recommends Boundary 6.5 EC or Prefix preemergence herbicides, each containing two SOAs. Before weeds reach 4 inches; it’s recommended to follow Boundary 6.5 EC with a postemergence application of Prefix with glyphosate or Flexstar GT 3.5 herbicide.

“Although increasing weed control measures to comply with the adjusted Chinese weed seed import restrictions could mean putting more money into weed management up front, keeping weeds out of your fields can result in higher yields and increased profit at the end of the season,” he notes. “The Resistance Fighter program offered by Syngenta provides localized weed management solutions crafted by agronomy experts who live and work in your area.”

To learn more, visit resistancefighter.com.

Source: Syngenta