Multiple herbicides in the tank improves weed control
Tank mixes improve the spectrum of weed control, says Tim Fransen.
The herbicide tank mix Tim Fransen used on corn and soybeans in 2012 cost one-third to half again as much as the two shots of glyphosate he traditionally used. But Fransen has no regrets making the additional investment, noting it’s more cost effective to prevent weeds than control them. The bigger challenge, he says, was figuring out what combination of herbicides to put in the tank.
"There are so many products out there now, with resistance coming in the past few years, it seems like every company has jumped on the bandwagon with new herbicides, premixes and rebranding of old products," notes Fransen, who farms with his dad and uncle near Jackson, Minn.
Farmers are taking a closer look at using herbicide tank mixes to improve weed control, according to a recent poll conducted at the 2013 Commodity Classic by DuPont Crop Protection. Of the 130 farmers the company interviewed, more than half say they have changed their herbicide tank-mix strategies within the past three years.
"After years of relying on herbicide-tolerant crops and one herbicide mode of action, more growers are placing an emphasis on tank mixes again," says Jenny Goodman, DuPont soybean herbicide portfolio manager.
Goodman says the farmer poll revealed several concerns regarding the use of tank mixes. The No. 1 worry, referred to as extremely or moderately challenging by respondents, was the ability to correctly mix and apply herbicides to prevent crop injury. Other issues that respondents reported
included accurately measuring herbicides; knowing how much product to use; successfully cleaning tanks and clogged spray nozzles; time-consuming processes; and confusing product labels.
Fransen acknowledges having some of the same concerns and says there is only one way to alleviate them: "You have to do your research."
His research strategy starts with going online to check out articles, product labels and product-specific company literature. If he has questions, Fransen calls his crop protection salesman for help.
"Most are willing to work with farmers, give their opinion and advice, and even come to your farm, so don’t be shy about calling them up," he advises.
"I also talk with my neighbors and other farmers in the area about what’s working for them or not working," Fransen adds. "If they’re trying something different in their fields I try to see how it works out for them."
Likewise, in 2012, Fransen’s neighbors had the opportunity to see how well his new tank-mix strategy worked. What they saw was improved performance. "The tank mix helped us get the weeds that glyphosate alone didn’t get," he reports.
That’s a key take-home message for farmers who use a premix or tank mix of two or more herbicides, says Gordon Vail, technical product lead for Syngenta. He encourages farmers to determine whether the products they select offer multiple modes of action as well as no weed resistance issue for their geography.
"If one mode of action is an ALS inhibitor and you have ALS-resistant weeds, for instance, that means a two mode-of-action product essentially only has one mode of action that works against that weed," Vail explains. "When you’re considering a herbicide, it’s important to think, ‘What components in this product are actually controlling the weeds I have at the time I’m spraying them?’"
Fransen says he used tank mixes in both corn and soybeans this past season and got improved control of cocklebur, giant foxtail, lambsquarters and glyphosate-resistant waterhemp. His herbicide program in corn was approximately $16 an acre in 2012, while his soybean program ranged from $18 to $20 an acre. His standard glyphosate program had been less than $10 an acre.
"Having weeds get out of control can cost more than what your herbicide costs," he says.
In corn, Fransen applied a tank mix at the V3 growth stage that included glyphosate as well as Realm Q, a premix that contains the active ingredients rimsulfuron and mesotrione. Rimsulfuron is an ALS product, while mesotrione is an HPPD inhibitor. The two active ingredients work in plants at different sites of action, which can make control more comprehensive.
Farmers who use products in the tank that address more than one site of action for weed control are able to reduce stress in their crops which, in turn, protects valuable yield potential, adds Luke Bozeman, BASF technical market manager.
In soybeans, Fransen used a preemergence product, Enlite, right after the planter, on part of his acres. The herbicide contains three active ingredients: chlorimuron ethyl, flumioxazin and thifensulfuron methyl (Classic, Valor and Harmony, respectively). He scouted the crop and in mid- to late- June applied glyphosate with Assure II (quizalofop) for volunteer corn.
"Putting the pre-application down on soybeans is weather-dependent. If it’s dry we may not get the control we’re looking for, so we leave it open to coming back in with a post product, if need be," Fransen says.
On the remainder of his soybean acres, Fransen made two applications of Roundup or one application of Roundup with Flexstar (diphenyl ether). He keeps a close eye on his soybean crop throughout the month of June to make sure the crop stays weed-free, adding that he likes to make all herbicide applications in soybeans prior to the reproductive stage to minimize stress.
Proper Tank-Mix Procedures
Follow these guidelines to mix products and determine the sequence.
1. Fill the spray tank to at least 50% full. Run agitation.
2. Add any water conditioners.
3. Add any WDG; allow 10 minutes for complete dispersion.
4. Add any suspension-concentrate products.
5. Add any emulsifiable-concentrate products.
6. Add any soluble liquid products.
7. Fill the spray tank to nearly full.
8. Add any glyphosate-based products.
9. Add any adjuvants and fill the tank.
You can e-mail Rhonda Brooks at firstname.lastname@example.org.