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ISSUE 14  August 1, 2002



Syngenta Crop Protection Inc. and E.I. du Pont de Nemours & Co. announced co-promotion and supply agreements involving the companies' leading corn herbicides. The agreements specify that:

  1. Syngenta will supply herbicides with the active ingredient S-metolachlor-which is contained in Syngenta's Dual II MAGNUM and Bicep II MAGNUM herbicides-to DuPont for marketing and sale under DuPont's own brand names. These brand names will be announced shortly.
  2. DuPont will promote Syngenta's new Callisto herbicide as its lead recommendation for post-emergence, broadleaf weed control in corn.
  3. Syngenta will label and promote DuPont Accent and DuPont Steadfast herbicides as its lead recommendations for post-emergence grass control in corn. This multi-year agreement will take effect with the 2003 crop season.



Scientists have speculated for decades that spotted knapweed is able to spread over large areas because of a secret weapon - an ability to release a chemical that kills surrounding plants. How long have scientists known that spotted knapweed may secrete chemicals? This theory was suggested as early as 1832, but scientists have not been able to identify the chemical secreted by spotted knapweed that is responsible for killing other plants.

Recently a Colorado State University horticulture biotechnology professor, Jorge Vivanco, identified and isolated the chemical and are using the chemical to control other weeds. This discovery and isolation of the chemical, called catechin, within spotted knapweed may aid in the war against weeds.

Scientists could not find this chemical in the soil because it was almost impossible to separate from all the other compounds that naturally occur in soil. Scientists found spotted knapweed releases catechin into the soil through its roots. They discovered the weed produces two types of catechin that are the same chemical compound

but the mirror image of each other in their structure. The two different types of catechin are produced and secreted by spotted knapweed at the same time and in the same amounts. One catechin, called (-)catechin, is the natural herbicide that is toxic to other plants. The other, called (+)catechin, has antibacterial properties and has been commercially available for several years as an antioxidant and anti-aging compound. Until now, (-)catechin was considered a by-product with no commercial value. These mirror-image compounds are called racemic and are very rare in nature. They occur in chemical synthesis in laboratory settings, but the spotted knapweed's catechin is one of the first examples of racemic compounds that occur naturally in plants.

Now that catechin has been identified and isolated, scientists can explore number of applications for the chemical. The chemical acts as a natural herbicide to most other plants, although grasses and grassy-like plants, such as wheat, display some resistance to it. Some uses could be weed control in lawns and small grain crops. The chemical is environmentally friendly and has existed in the soil for decades.

Catechin kills diffuse knapweed, which also is a noxious weed but appears to have no affect on spotted knapweed when reintroduced to plants.

The Colorado State team has found that spraying catechin on plants or adding it to soil is as effective as 2,4-D against pigweed, lambs quarters, and other common weeds. Catechin kills plants in about a week, but scientists are investigating the length of time that it remains active in the soil to prohibit plant growth. The researchers are working with commercial companies to make spotted knapweed catechin spray available to consumers within a year or two.

Colorado State researchers also are working to transfer the genes that produce the natural chemical into other plants to give them a built-in defense mechanism against weeds.

Perhaps one of the most promising applications of the discovery is the fact that spotted knapweed has such a complex defense mechanism. Spotted knapweed immediately begins to produce and release chemicals at the slightest hint of a threat or stress. Just tapping its leaves automatically activates the plant's chemical response. The funding for these projects comes from Colorado State University's Invasive Weeds Initiative.



EPA Office of Pesticide Programs Participates in International Pesticide Management Conference in Saskatoon, Saskatchewan, Canada. The first international Pest Management Strategic workshop was held on June 26 and 27 in Saskatoon Saskatchewan, Canada for pulse crops consisting of dry peas, chickpeas and lentils. The workshop participants included growers, commodity leaders, university specialists, processors, Canada's PMRA, IR-4, and EPA. The main thrust of the workshop was to give the 50 participants an opportunity to take a pest-by pest approach for these 3 pulse crops and then to focus on research, regulatory and education developmental needs in the future.

Presentations were given by PMRA, IR-4 and EPA. The workshop was facilitated by Rick Melnicoe of the University of California. A draft of the strategic plan for these pulse crops is anticipated in the August/September 2002 timeframe. These plans are expected to be useful tools in transition as older chemicals are reassessed and evaluated according to FQPA requirements.



Minor uses of pesticides are those for which the total United States production for a crop is fewer than 300,000 acres. Minor use also applies to pesticide uses which do not provide sufficient economic incentive for a registrant to support initial or continuing registrations. EPA has prepared a Report on the Minor Uses of Pesticides mandated by Section 13 of the FIFRAct as amended by the Food Quality Protection Act of 1996 (FQPA). The report describes actions taken by EPA to increase communication with minor use stakeholders and expedite registrations for minor use pesticides. To accomplish this, EPA has designated a minor crop advisor and a public health coordinator to increase responsiveness to minor use concerns. The report also describes the coordinated approach between EPA, USDA and the Department of Health and Human Services (DHHS) required by FQPA for dealing with minor use issues.

EPA in partnership with USDA’s Interregional Research Project 4 (IR_4) has aggressively sought to increase pesticide registrations for minor uses, registering 814 new uses in 1999 and 901 in 2000. Over 80% of the new use registrations have been for reduced_risk pesticides. In conducting its minor use related activities, EPA has embraced core FQPA implementation principles including:

The EPA Minor Use Team has three primary goals:

  1. Obtaining and Using the Best Available Usage Data by; supporting processes for users to be able to provide real world data and verify that the data are used, strengthening cooperation with USDA and the minor use community to generate and/or obtain data, and using EPA’s Pesticide Environmental Stewardship Program (PESP) to increase and improve communication with minor use stakeholders;
  2. Facilitating Open Dialogue with the Minor Use Community by increasing involvement with stakeholders early in the regulatory process; and
  3. Promoting Development of Reduced Risk Pesticides for Minor Uses by supporting efficacy testing of new products and working with IR-4 to expedite registration of reduced risk pesticides for minor uses.

The report can be accessed at:


Richard Zollinger
NDSU Extension Weed Specialist


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