Michael Doane, Manager, Industry Affairs, Monsanto Company
800 North Lindbergh Blvd, A2NG, St. Louis, MO 63167
Phone: 314-694-8351; Email: michael.k.doane@monsanto.com

Roundup Ready spring wheat is a biotech product that allows over-the-top spraying of Roundup herbicides. The product concept for Roundup Ready wheat is complete, dependable, cost-effective control of nearly all weeds, often with only one herbicide application.

Monsanto has conducted Roundup Ready spring wheat field trials since 1994 with very positive results. Trials have found that Roundup Ultra provides equal or superior weed control when compared to other commercial herbicides. The Roundup Ready system in wheat offers farmers a compelling value proposition. The benefits include broad-spectrum weed control, yield improvement, a new in-crop mode of action, increased crop safety, simplicity, conservation-tillage enhancement, cleaner grain, and no crop rotation restrictions – all combined with the environmental benefits and safety profile of Roundup herbicides.

Three years of field trials in the United States and Canada indicate that a single 32-fluid-ounce application of Roundup Ultra over the top of Roundup Ready spring wheat up to the five-leaf stage provides 95 to 100 percent control of nearly all broadleaf and grassy weeds. These problem weeds include:

• Brome, downy
• Chickweed
• Cocklebur
• Falseflax, smallseed
• Field pennycress
• Foxtail
• Goatgrass, jointed
• Groundsel, common
• Henbit
• Horseweed/marestail
• Kochia
• Lambsquarters
• Mustard (blue, tansy, tumble, wild)
• Pigweed
• Quackgrass
• Thistle, Canadian
• Wild buckwheat
• Wild oats
• Wild rye

Results from 1999 and 2000 Roundup Ready spring wheat field trials demonstrated consistent efficacy across locations and years, and virtually no crop injury for any Roundup Ultra treatment.

Yields were significantly higher in side-by-side comparisons with Roundup Ultra vs. alternative herbicides applied to Roundup Ready spring wheat. This substantial yield advantage is likely attributed to a combination of more complete weed control and improved crop safety.

The in-crop use of Roundup herbicides in spring wheat provides growers with an additional mode-of-action for managing herbicide-resistant weeds. The family of Roundup herbicides has a unique mode-of-action as an EPSPS inhibitor. Roundup herbicides act only on weeds that have germinated and emerged from the soil. They do not control weeds that haven’t emerged. These are some characteristics that make the development of weed resistance unlikely.

Field trials in 2000 confirmed the superior crop safety of Roundup Ultra treatments vs. alternative herbicides in Roundup Ready spring wheat. Roundup Ultra over Roundup Ready spring wheat had virtually no crop injury, compared to other herbicide treatments that averaged nearly 6 percent injury.

The Roundup Ready wheat system should increase grower flexibility – thanks to a wider, more flexible application window. Growers would have the flexibility to plant earlier since they could eliminate the need for pre-plant-incorporated herbicides. Growers would have flexibility in application timing during the growing season, and could make herbicide applications based on their needs and desires.

Using Roundup herbicides should encourage the adoption of conservation tillage practices that preserve soil moisture and reduce erosion of valuable topsoil. Additional benefits of conservation tillage include reduced fossil fuel use, improved wildlife habitat and increased carbon retention in the soil.

Typically, harvested grain in spring wheat regions of the United States and Canada average 2 to 4 percent grain dockage. An estimated 62 percent of this dockage is attributable to weed seed. Fewer weeds lead to less foreign matter in wheat grain.

Roundup herbicides bind tightly to soil particles and are readily metabolized by soil microbes, which means that there is no residual activity. Growers have the post-harvest flexibility to select the rotational crop of their choice.

The family of Roundup herbicides is environmentally responsible, has an excellent 25-year safety profile, and is known for its non-persistence, limited mobility and low toxicity. They are among the most widely used crop protection products in the world. Roundup herbicides have a favorable acute toxicity profile and present very low potential human health risks to herbicide applicators and consumers. Compared to most alternative herbicides, Roundup herbicides have very low toxicity to birds, bees, aquatic organisms and other wildlife.

We are committed to helping meet the needs of wheat growers by delivering consistent, effective and economical weed control solutions. However, we acknowledge that trade is a vital component of North American agriculture, and we will work with the wheat industry to identify how a biotech trait can successfully enter the marketplace.