Ongoing Evaluation Key to Controlling Weeds, Improving Yield in Soybeans

Soybeans weeds
A preemergence first strike against yield-limiting weeds, such as waterhemp and Palmer amaranth, can give soybeans the early season boost needed to improve yield potential.

As the sun bears down on record U.S. soybean acres this August, farmers keep their eyes on their fields to evaluate weed control decisions made earlier in the year. Ongoing scouting and peer discussions near harvest can help farmers fight back against persistent weeds the following season.

Every field potentially has unique weed management challenges depending on weather, soil type and weed control methods, which is why it’s hard to make decisions solely based on neighbors’ experiences. In addition to conversations with fellow farmers, Dow AgroSciences field scientist Dave Ruen recommends consulting with trusted retailers, herbicide and seed suppliers, and Extension weed scientists for additional support.

“At this point in the season, farmers can see weed control performance firsthand in their own fields and ask specific questions to improve their programs for the following season,” Ruen says. “Herbicide-resistant weeds, particularly Palmer amaranth and waterhemp, are top of mind for many Midwest farmers this year.”

Ruen offers advice on farmers’ three most common weed control questions this season:

Q: In areas where Palmer amaranth is not yet herbicide-resistant, what steps can farmers take to keep it from becoming resistant?
A: Palmer amaranth differs from other pigweed and waterhemp species due to its rapid growth. Farmers cannot let this weed get ahead of the crop.

With any potentially resistant weed, frequent and timely scouting helps farmers identify troublesome areas and formulate a timely postemergence herbicide plan. After postemergence applications, scouting allows farmers to identify at-risk fields where herbicide-resistant weeds may already exist and decide if it’s necessary to make a sequential herbicide application with an effective mode of action.

After applying full rates of broad-spectrum preemergence herbicides in the spring, farmers should alternate postemergence herbicides with mode-of-action-tolerant seed traits to avoid repetitive use of one active ingredient and to expand the mode-of-action family of options.

Another way farmers can battle herbicide-resistant weeds is to stay current on newly identified resistance in their geography and keep detailed notes of specific weed pressure in their fields. Electronic files are easy to customize for individual fields based on crops and known weeds, plus they can be used as visual aids to build an inventory or cropping mix, and program solutions for the 2018 season.

Q: How does rainfall affect the residual control of soybean herbicides?
A: Rainfall is needed for any herbicide to take effect in the soil for controlling weeds. As farmers look at the variability over the course of multiple seasons, the timeliness of needed rainfall partly depends on the soil temperature following application.

When soil conditions are cooler, weeds aren’t germinating as quickly, which provides a slightly larger window to receive rainfall. Under normal conditions, receiving rainfall within seven to 10 days after a herbicide application is ideal. If it’s extremely warm and it’s a late-spring application, an activating rain within three to four days will provide optimum performance of Sonic herbicide and other soybean herbicides. Sonic is proven to perform in a variety of soil types, including fields with slightly delayed activating rains.

Q: What is the best plan to control waterhemp in soybeans?
A: Ranked as one of the most troublesome and most common weeds of 2017 by the Weed Science Society of America, waterhemp can cause devastating yield loss if left uncontrolled. Research from the University of Illinois has shown waterhemp can cause up to 40 percent yield loss in soybeans.

A preemergence first strike against waterhemp can give soybeans the early season boost needed to improve yield potential. The best strategy to control waterhemp includes a program approach using preemergence and postemergence herbicides with multiple modes of action.

Commonly known as a summer annual, waterhemp germination and emergence also can extend late in the season. Waterhemp management needs to begin early with a preemergence residual herbicide that will provide long-lasting control. Sonic can be applied in the fall, preplant incorporated, preplant or preemergence up to three days after planting, before soybeans emerge. With two nonglyphosate modes of action, Sonic controls many broadleaf weeds resistant to glyphosate, including waterhemp, Palmer amaranth, giant ragweed and common ragweed.

Early season scouting can help farmers determine the appropriate window of application for a postemergence program.
To learn more about stopping hard-to-control weeds before they steal yield, visit BattleWeeds.com.

Topics:

Leave a Reply

Herbicides Stories

HerbicidesAg Secretary Perdue Comments on Dicamba Issue
August 9, 2017
Agriculture Secretary Sonny Perdue indicated to reporters this week that he would like to see the industry work out a Read More
Crop InputsMonsanto’s Fraley Addresses Dicamba Situation in Open Letter to Farmers
August 3, 2017
Monsanto Chief Technology Officer Robb Fraley — a man who has seemingly been at the center of Monsanto’s PR campaign Read More
Burndown-application-of-Elevore-herbicide
HerbicidesNew Era of Burndown Control Awaits U.S. Farmers
July 31, 2017
Trials across the Midwest and Midsouth conducted by farmers and retailers through Dow AgroSciences’ Field Forward on-farm research program showed Read More
Crop InputsBASF: In Arkansas Drift Cases, Buffer Zones Mostly Not Followed
July 24, 2017
BASF on Thursday addressed questions about spreading dicamba drift issues on a media briefing call. In Arkansas – which is Read More
Trending Articles
Iowa waterways
Stewardship2,600 Iowa Farmers Commit $8.7 Million to Water Quality Practices
August 9, 2017
Iowa Secretary of Agriculture Bill Northey announced Tuesday that a record number of Iowa farmers signed up to install nutrient Read More
Greg Musson, Gar Tootelian
CropLife 100Cause of Gar Tootelian Fire Under Investigation
August 7, 2017
Over one hundred firefighters and equipment responded to a four-alarm shop fire at the Gar Tootelian, Inc. (GAR) facility in Read More
Rob Versprille
ManagementCeres Solutions, North Central Co-op Merger to Bring New Opportunities for Indiana, Michigan Farmers
August 1, 2017
More than 40,000 customers and almost 9,000 Indiana and Michigan farmers will begin doing business with the new Ceres Solutions Read More
CPS-Norwood-and-Dupont-reps
Eric SfiligojA Message to Ag Retailers: Do Tell Your Good Stories
July 26, 2017
As the daughter of a peanut farmer, Krysta Harden, Chief Sustainability Officer for DuPont Crop Protection, understands the importance ag Read More
Tim Hassinger Dow AgroSciences President and CEO
Crop InputsDow’s Tim Hassinger Named President, CEO of Lindsay Corp.
July 24, 2017
Lindsay Corp. has  announced the appointment of Timothy Hassinger as president and CEO and a member of its board of Read More
Stewardship‘Gonna Fly Now’ with Environmental Respect
July 20, 2017
One of the most memorable moments in movie history occurred in the Academy Award-winning 1976 film “Rocky.” Haven gotten his Read More
Latest News
Corn Seed
Seed/BiotechSeed Innovations Benefit All of the Seed Industry
August 17, 2017
Innovations from throughout the seed industry help address many of the economic, environmental and health issues we face as a Read More
SpreadersGVM to Introduce New Prowler at MAGIE
August 17, 2017
The newest Prowler in GVM’s line-up will be introduced next week at the Midwest Ag Industries Expo (MAGIE), August 23 Read More
AcreEdge bag
Seed/BiotechLandus Cooperative’s AcreEdge Seed Brand Gears Up for 2…
August 17, 2017
Growers in more than 26 Iowa and Minnesota counties are seeing field signs with a new brand name at end Read More
Engenia soybeans
ManagementCorn and Soybean Yield Forecasts Larger than Expected
August 17, 2017
The USDA’s August Crop Production report contained larger-than-expected forecasts for the 2017 U.S. corn and soybean crops. At 169.5 bushels Read More
ManagementU.S. Ag Secretary Introduces SCORE
August 17, 2017
U.S. Agriculture Secretary Sonny Perdue signed a new agreement to support new and beginning farmers. On August 5, Perdue joined Read More
CHS-FFA-Minnesota
CropLife 100CHS and FFA: A Homerun Partnership
August 17, 2017
CHS hosted the Minnesota FFA for its annual FFA night at CHS Field. FFA students, educators and CHS leadership enjoyed Read More
Greg Musson, Gar Tootelian
CropLife 100Gar Tootelian Foundation Donates Half Million Dollars t…
August 16, 2017
Students at Immanuel Elementary are looking forward to the first day of school for two reasons this year. One, they Read More
Water Drainage
StewardshipNew System Could Remove Two Water Pollutants from Ag Fi…
August 14, 2017
Algae blooms in the Gulf of Mexico use up the majority of the oxygen in the water, leading to massive Read More
Eric SfiligojThe Top 10 Crop Protection Companies, Post-Mega Mergers
August 14, 2017
Everyone loves a good Top 10 list. In fact, some prominent celebrities such as David Letterman spent much of their Read More
ManagementThe DuPont-Granular Deal, Dicamba Update, and Upcoming …
August 11, 2017
Matthew Grassi joins Paul Schrimpf for the second week in a row to talk about DuPont’s acquisition of Granular, as Read More
Soybeans weeds
HerbicidesOngoing Evaluation Key to Controlling Weeds, Improving …
August 10, 2017
As the sun bears down on record U.S. soybean acres this August, farmers keep their eyes on their fields to Read More
Young Corn Plants
Seed/BiotechMycogen Seeds Offers Novel Product to Battle Pythium, O…
August 10, 2017
After a season plagued by seedling diseases caused by cool, wet soils at planting, farmers have a new option to Read More
Corn Field
FertilizerProtect Applied Manure Straight From the Manure Pit to …
August 10, 2017
Farmers who use liquid manure to fertilize corn crops can now mix Instinct nitrogen stabilizer in their pit for easy Read More
Iowa waterways
Stewardship2,600 Iowa Farmers Commit $8.7 Million to Water Quality…
August 9, 2017
Iowa Secretary of Agriculture Bill Northey announced Tuesday that a record number of Iowa farmers signed up to install nutrient Read More
Natives-First-Purple_Prairie_Clover
Seed/BiotechLa Crosse Seed Continues Focus on Soil and Water Conser…
August 9, 2017
La Crosse Seed is doing its part to lead communication to ag retailers across the country on the importance of Read More
HerbicidesAg Secretary Perdue Comments on Dicamba Issue
August 9, 2017
Agriculture Secretary Sonny Perdue indicated to reporters this week that he would like to see the industry work out a Read More
Treated-Seed-in-planter
Seed/BiotechSeed Treatment Q&A: Insight from Iowa State’s…
August 8, 2017
Technology has changed drastically since the 1990s. Televisions are thinner, phones are smaller and tractors can steer themselves. Technology has Read More
soybeans
Seed/BiotechWhen and Why to Double Inoculate Your Soybeans
August 8, 2017
Double inoculation is the act of using a double application of a rhizobial inoculant. This quickly establishes high populations of Read More