Corn and soybean producers will have some new and a few updated products for weed control in 2008. Corn seems to be the major beneficiary of the new herbicides, which isn't surprising given the continued increase in corn plantings. These new products either enhance glyphosate's effectiveness or provide a different mode of action.
Postemergent corn herbicide
Bayer CropScience offers a new post-emergent corn herbicide. Laudis uses an HPPD (hydroxyphenylpyruvate dioxygenase) mode of action to control a wide range of grass and broadleaf weeds.
“In the majority of acres where Laudis will be used, probably 70 to 80%, the product is going to be in a tankmix with Roundup or glyphosate to control resistant and segregating weeds,” says Jeff Springsteen, Bayer CropScience product manager for Laudis. “One pint of Roundup with 3 oz. of Laudis will be a dynamite combination.”
Laudis also can be tank mixed with Liberty. “These two chemistries have never shown weed resistance anywhere in the world,” Springsteen says. “We'll be positioning 2 oz. of Laudis with 32 oz. of Liberty. Growers will get outstanding contact and residual weed control.”
A new portfolio of products, called Technology for Traits, from Dow AgroSciences will bring three products for herbicide-tolerant corn and soybean production systems, specifically Roundup Ready corn and soybeans.
“We are seeing major shifts in agricultural production,” says Damon Palmer, product manager for Dow AgroSciences. “With more than 90% of U.S. soybeans now being planted with the Roundup Ready trait, and corn quickly heading that way, we're developing a system that provides new weed-control tools in herbicide-tolerant crops.”
Palmer says the Technology for Traits platform helps with stewardship of the glyphosate molecule by offering another weed-control option. In addition, the platform uses residual products to help maximize yields.
SureStart is a soil-applied herbicide for use in Roundup Ready corn. It provides broad-spectrum control for early emerging grasses and both small- and large-seeded broadleaf weeds for up to six weeks. It can be applied from preplant up to 11-in.-tall corn. “University research has shown that these weeds compete for moisture, sunlight and nutrients, which reduce the yield potential of corn,” Palmer says. “It is designed to complement glyphosate in a Roundup Ready system.”
Sonic herbicide uses two modes of action to deliver broad-spectrum broadleaf weed control in Roundup Ready soybeans.
Durango DMA herbicide contains a third-generation glyphosate salt that delivers broad-spectrum control of more than 100 broadleaf weeds and grasses. “It is tankmix-compatible with fungicides, insecticides and herbicides, particularly with phenoxy herbicides like 2,4-D,” says Dave Ruen product technology specialist with Dow AgroSciences.
Designed specifically for glyphosate-tolerant (Agrisure GT and Roundup Ready) corn hybrids, Halex GT from Syngenta is a postemergence herbicide that offers glyphosate with residual control. According to the company, this combination delivers control of weeds present at emergence and residual activity to manage multiple weed flushes, eliminating the need for additional herbicide applications.
“Halex GT offers producers a wider application window and greater flexibility,” says Carroll Moseley, herbicide brand manager for Syngenta. “It delivers a more convenient, agronomic and higher-yielding alternative to any glyphosate-only, postemergence program used today.”
Containing three active ingredients — mesotrione (the active ingredient in Callisto), S-metolachlor (the active ingredient in Dual Magnum) and glyphosate (the active ingredient in Touchdown HiTech) — in one easy-to-use product gives growers the “best opportunity for one-pass, postemergence weed control in glyphosate-tolerant corn,” Moseley says. “We recognize that a significant segment of the market is moving to post-emergence weed control in glyphosate-tolerant corn, and Halex GT is a perfect fit for these systems.”
Rates vary from 3.6 to 4.0 pints/acre, and the optimum application timing is early postemergence before weeds reach 4 in. in height.
Products for corn and soybeans
To address changing weed-control needs in glyphosate-tolerant corn and soybeans, DuPont is launching several new products for which EPA registration is pending.
According to the company, its two new postemergence corn herbicides with built-in safener technology will provide greater crop tolerance while providing better, more consistent grass and broadleaf weed control under more weather conditions and with a choice of adjuvants. The company says its two new preemergence soybean herbicides will offer contact plus residual control of annual weeds even under cool, wet conditions, allowing post application closer to crop canopy.
“Using a residual herbicide as part of a glyphosate-tolerant program is key to effective crop management,” says Wayne Schumacher, DuPont corn and soybean product launch manager. “DuPont Crop Protection has corn and soybean herbicides that fit all grower programs, whether conventional or no-till, and excel at preplant, preemergence, post-emergence and post harvest grass and broadleaf weed control.”
Monsanto says its Roundup PowerMax is a new Roundup herbicide formulation that performs more consistently from weed to weed and field to field. It replaces Roundup Original Max. More than 1,000 growers and retailers previewed PowerMax during the 2007 growing season on more than 300,000 acres.
“Roundup PowerMax delivers outstanding consistency of weed control and crop safety,” says Chad Bush, Roundup marketing manager. “It sets a new standard in Roundup performance with more powerful weed control than Roundup Original Max.”
Amvac Chemical has added five grass and broadleaf weeds to its Impact post-emergence corn herbicide label: green foxtail, dandelion, Powell amaranth, marestail and hairy galinsoga. Shattercane suppression has been added to the label.
In addition, rotational cropping flexibility has been increased in Iowa, Illinois and Nebraska. Under the new label, the rotation interval for soybeans is nine months throughout the three states when Impact is applied at 0.75 oz./acre. In the past, the northern portions of the three states had a nine-month soybean rotation interval at 0.5 oz./acre.
Precision Laboratories is marketing Simplyx, a nonionic activator adjuvant specifically formulated to enhance the performance of glyphosate and its tankmix partners. According to James Reiss, vice president of agricultural business at Precision Laboratories, Simplyx maximizes the performance of both glyphosate and oil-soluble tankmix partners such as Select and FirstRate.
EPA approval is expected for the 2008 growing season for Select Max herbicide's use as a control of Roundup Ready corn stands during replanting situations. According to Mark Kitt, spokesman for Valent, Select Max provides fast, flexible and consistent control of Roundup Ready corn hybrids.
“When a producer is in a replant situation in a Roundup Ready corn stand, Select Max at 6 oz. to the acre provides fast, effective control,” he says. “A producer can then be back in the field to replant in six days.”