What is in this article?:
- Back to Bean Basics? | Weed Resistance Prompts Some Farmers To Grow Soybeans the Way They Used To
- Evaluating costs
John Jacobs has always used glyphosate to clean up weed problems on his farm, especially problem fields. But for the most part, he’s never really strayed from a conventional weed-control program for his soybeans. “My basic plan is to plant beans, and use Prowl and Valor in the spring,” he says. “My weed-control program is about $20/acre, but I’m not paying a tech fee.”
Jacobs, from Napoleon, OH, says his weed-management program does take some more time and some additional scouting. “But I like to stay in touch with what my real weed problems are,” Jacobs says. “Just going out and blasting everything with glyphosate would control weeds, but you’d lose track of what weeds you need to control.”
And Jacobs says he continues to look at economic thresholds. “Weeds can cut into yields, but I use guidelines to determine if the control will cost more than the return,” he says. “I look to see if the weed pressure is economically damaging. Even if glyphosate is cheap to spray, that doesn’t always mean it’s giving you a payback.”
Glyphosate remains a very important and effective tool in a weed-management program. And with more than 90% of today’s soybeans planted with the Roundup Ready trait, its popularity shows that glyphosate is still the odds-on choice for weed control in beans. But the appearance of glyphosate-resistant weed biotypes has exploded in recent years, and more and more producers are adding a pre-emergence and/or postemergence herbicide to the mix.
“Glyphosate alone is not recommended,” says Mark Loux, Extension weed scientist at Ohio State University. “While it still offers a control, we stress the need for additional herbicides in the mix.”
Bob Streit, owner of Central Iowa Agronomics in Boone, IA, says: “Over 12 years, we have selected for weeds that are tolerant or resistant to glyphosate. Residual herbicides have been recommended for several years, and now we are seeing different weed-control methods with residuals being used in many herbicide programs.
“And if a producer can get good weed control without needing glyphosate, he can skip the tech fee and put that money into a pre- or postemergence weed-control program,” Steit says.