Search Site   
News Stories at a Glance
Deere 4440 cab tractor racked up $18,000 at farm retirement auction
Indiana legislature passes bills for ag land purchases, broadband grants
Make spring planting safety plans early to avoid injuries
Michigan soybean grower visits Dubai to showcase U.S. products
Scientists are interested in eclipse effects on crops and livestock
U.S. retail meat demand for pork and beef both decreased in 2023
Iowa one of the few states to see farms increase in 2022 Ag Census
Trade, E15, GREET, tax credits the talk at Commodity Classic
Ohioan travels to Malta as part of US Grains Council trade mission
FFA members learn about Australian culture, agriculture during trip
Timing of Dicamba ruling may cause issues for 2024 planting
   
Archive
Search Archive  
   
Defeating weeds in Midwest soybeans a challenging task

By CELESTE BAUMGARTNER
Ohio Correspondent

COUMBUS, Ohio — When it comes to weed management farmers need to be persistent, said Roger Bender, a member of The Ohio State University’s Agronomics Crop Network and the OSU extension agent in Shelby County.

“It can be a challenge because we gear up for simplicity if we can, and that’s what a glyphosate (systemic herbicide) program offered us,” Bender said. “Unfortunately, with too much reliance on that, maybe waiting too long to spray weeds, they get bigger and then we don’t actually kill them – we stun them, but they still produce seeds. That seed can have a certain amount of resistance for that herbicide that following year.

“As farmers we all want to be as economical as we can be, but sometimes cheating on the rates or timing of products, or maybe the lack of a second treatment, costs us in the long run because then we end up with some resistant weed seeds coming through.”
Glyphosate has given farmers a false sense of security, said Dr. Mark Loux, OSU state extension specialist. Some weeds have developed a resistance to the herbicide, plus, “It is typically known that producers can kill 10- to 20-inch weeds if they have to,” he explained. “The problem is that weeds that are bigger than about six inches tall have the potential to start reducing the soybean yield.”

Loux said OSU encourages farmers to spray when weeds are in the three- to six-inch range and then make a second application if they need to, rather than waiting until everything is 10-20 inches tall and trying to get by with one post-application. A pint of 2, 4-D in the spring helps extend the effectiveness of glyphosate and glufosinate (a nonselective systemic herbicide) programs, Bender added.

“But if you’re still looking to plant beans, then it’s a seven-day wait if you apply a pint of 2, 4-D, he said. “At this stage of the game folks are looking for any kind of program that can burn what’s there, and hopefully that will offer some extended value in terms of controlling weed seedlings that pop up.”

That’s important for farmers who are growing conventional beans, Bender said.

“A substantial number of farmers are doing that, growing non-GMO (genetically modified) beans,” he said. “There is a market premium this fall, I’ve heard anywhere from $1.50 to over $2 a bushel; it is significant.”

Whatever kinds of beans are in their fields, farmers need to scout, Loux said. “There is a tendency to wait until you can see from the road when the regrowth is up above the soybeans,” he said. “It’s like mid- or end of July.

Most of our data shows that for both the late emergers and weeds that, for whatever reason, survive the first application, about three weeks after the first application is really the correct timing for the second application. You have time for regrowth but they are not large yet.”

Farmers have the problem of looking at the field and seeing the weeds are not that tall. The beans are starting to canopy over the weeds and farmers fear they won’t get coverage on those weeds, Loux said. “Our data shows that that is not the case,” he said. “You are better off to spray; you will get herbicide down where it needs to go. You’re much better off than to wait until the weeds poke above the crop canopy, because the weeds are big and robust and you’ll have a tough time killing them.”

Bender recommended the following sources for more information on weed management:

•The 2009 Ohio and Indiana Weed Control Guide is available in any extension office in Ohio or Indiana
•Visit the Crop Observation and Recommendation Network (CORN) website at www.corn.osu.edu
•In Indiana, Bob Nielson’s website has good advice: www.kingcorn.org

6/17/2009