Farm Progress is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Serving: United States
Corn+Soybean Digest

Weed Killers With Wallop

As planting season nears, once again there's no new chemistry in the crop protection pipeline. Crop protection companies are offering new formulations of older products, working to improve product viscosity and concentration for faster application and, of course, to provide consistent performance.

A few products fill niche markets or are offered as residuals to clean up glyphosate-tolerant or resistant weeds.

Meanwhile, some growers are taking measures to not take advantage of a good thing — glyphosate, says Jeff Gunsolus, University of Minnesota Extension weed specialist. “Basically, some farmers are paying heed (to glyphosate tolerance or resistance problems).”

“The common strategy is planting Liberty corn and then Roundup soybeans. Or they're going with conventional herbicide programs in corn and Roundup soybeans,” he says. “There's no doubt that Roundup soybeans are the base of most of these programs unless growers are finding a niche.”

Six soybean herbicides have been newly introduced for the 2004 growing season. They are:

Arrow Makhteshim Agan, from Makhteshim Agan of North America (MANA), is generic clethodim, best known as Select herbicide, from Valent. The Arrow product allows growers to stay in a Roundup Ready corn and soybean rotation, according to John Frieden, MANA product director.

“Arrow is highly effective in controlling volunteer Roundup Ready corn,” Frieden points out. “Alone or in a glyphosate tankmix, Arrow controls this aggressive variety of volunteer corn in Roundup Ready soybeans, especially when conditions are appropriate for significant populations.”

Weed specialist Gunsolus says products such as Arrow and Select are effective tankmix partners with glyphosate to control volunteer corn. “There are other post grass herbicides registered for tank mixtures with Roundup to kill corn,” he says. “And it's true, if you have a lot of Roundup-resistant volunteer corn and let it go too long, it could affect soybean yields. You could also get docked at the elevator for having corn contaminate in your beans.” Arrow is effective against most grasses.

Roundup UltraMax II is a new potassium salt formulation offering a higher concentration that pumps well in cold weather, says Jeff Koscelny, Monsanto Roundup technical manager.

“We had pretty well maxed out how concentrated the formulation could be using the isopropylamine salt of glyphosate. The predecessor, Roundup UltraMax, contained 3.7 lbs. of glyphosate acid/gal. We didn't dare go higher than that without running into severe viscosity issues, so we needed to change to potassium salt,” Koscelny adds.

“The net result is a 4.5 lb. acid. This higher concentration means reduced use rates so a guy who takes a shuttle to the field to spray can spray a lot more acres. It also has great viscosity, so in cold weather, pumping is no longer an issue.”

The newest Roundup product also offers a new and improved delivery system, called Transorb II Technology. It uses a different surfactant system from the old Transorb technology and delivers more consistent performance, Koscelny says.

Roundup UltraMax II is being targeted toward the harsher environments of the Plains region, including North and South Dakota, Montana, Wyoming, Colorado and Kansas.

Intrro, also from Monsanto is a similar formulation to the familiar Lasso, says Greg Elmore, U.S. technical manager for soybeans. It's an alachlor-based pre-emergence option for control of grasses and small-seeded broadleaf weeds in soybeans and grain sorghum. Unlike Lasso, it's not registered for corn.

“We've looked at Intrro as a product that works well for growers who want to use a residual product down and then come back with Roundup,” Elmore adds.

Commit 3ME, from Agriliance, is clomazone, just like FMC's Command 3ME, says Eric Spandl, an Agriliance agronomist. “We're trying to give our customers a comprehensive line in terms of active ingredients,” he adds. Commit is a preplant/pre-emergence product that controls grasses such as foxtails, crabgrasses, barnyardgrass and seedling johnsongrass as well as broadleaves such as velvetleaf, jimsonweed, kochia and lambsquarters.

Recoil, from Nufarm Americas, combines glyphosate and 2,4-D acid.

“Recoil incorporates glyphosate with an adequate concentration of 2,4-D acid,” says Tim Birkel, NuFarm's marketing specialist. “2,4-D acid eliminates volatility and provides the extra kick needed for tough broadleaf weeds showing signs of glyphosate tolerance. We're seeing quicker weed takedown and marketing it in a variety of areas for applications including in-crop Roundup Ready corn, preplant soybeans and burndown of tough perennial weeds.”

Touchdown Total, from Syngenta, is labeled for over-the-top use in glyphosate-tolerant soybeans and as a pre-emerge burndown for conventional and glyphosate-tolerant crop systems.

A non-selective potassium glyphosate, its use rate is 24 oz./acre (1.5 pts.). Highly concentrated, it treats 5.3 acres/gal., allowing growers to store, handle and apply less product.

It works especially well on difficult broadleaf weeds, including lambsquarters, foxtails, velvetleaf, waterhemp and common and giant ragweed.

A 4.17-lb./gal. acid equivalent formulation, Touchdown Total contains the company's fully loaded IQ technology adjuvant system.

Hunting For Herbicide Resistance Info?

To get a report of which weeds are resistant to which herbicides in your state and beyond, check out a comprehensive Web site called The International Survey of Herbicide Resistant Weeds.

Key in The site monitors the evolution of herbicide-resistant weeds and assesses their impact throughout the world.

It's a collaboration among weed scientists globally and lists herbicide-resistant weeds by country and by U.S. state.

Click on Global Summary to check out how many resistant weeds Brazilian growers are fighting (11) compared to what U.S. farmers are battling (107). For a peak at herbicide resistance problems in your state, click on U.S. State Map. Click on your state to get a specific report on what's resistant, when it became so, its mode of action and other pertinent information.

The site is funded by the Herbicide Resistance Action Committee (HRAC), the North American Herbicide Resistance Action Committee (NAHRAC), and the Weed Science Society of America (WSSA).

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.