RECOMMENDING CONSUMER PRODUCTS FOR LAWN CARE. S. Askew*, Virginia Tech, Blacksburg, VA (91)

ABSTRACT

   Homeowners, Master Gardeners, and Extension Agents have long complained that consumer herbicides were generally ineffective and information found in the Virginia Cooperative Extension Pest Management Guide (PMG) did little to aid consumers in product selection and use rates. In 2010, the Lawn Weeds section of Virginia Home Grounds and Animals PMG was corrected to address complaints from concerned individuals. The following problems were noted and corrected: 1) pest management recommendations were based on common chemical names of active ingredients yet most consumer products contain the full chemical name and not the common chemical name. To correct this problem the Virginia Department of Agriculture and Consumer Services (VDACS) database was searched to identify approximately 700 consumer herbicides that represented 34 unique active ingredients. Interestingly, over 560 of these consumer products contained various combinations of just 8 active ingredients. A table was created to shows all synonyms that were filed with VDACS for consumer herbicides registered in Virginia and the number of consumer products that uses each active ingredient. The table of synonyms allows consumers to cross reference the full chemical names with the common chemical name used in the PMG. 2) In the old PMG, herbicide rates were expressed in pounds active ingredient per acre and of little use to consumers.  Extension Agents, who understood these rates, could not find any consumer products that matched or allowed for equivalent use rates to those recommended in the PMG. To correct this problem, a professional equivalency formula was created and professional equivalency constants (PEC) were calculated for each unique combination of active ingredients registered in Virginia. The formula uses the percentage active ingredient, amount of product per container, and square footage treated per product container to determine how the consumer product compares to professional rates that are recommended by Virginia Tech. Most consumer products were found to be 0.46 to 0.79 times the recommended professional rate. Consumers are advised to choose the product that returns a value closest to 1 when using the formula. When evaluating consumer product labels, it was noted that many products have a suggested use rate followed by a maximum use rate. The maximum use rate is often expressed in pounds of active ingredient per acre and is not understandable by consumers. These maximum rates are typically twice the suggested rates and less than the professional rates on which the PEC is based. As an extension specialist, one struggles to give consumers and Extension Agents sound advice in using consumer products when suggested rates on these products are far less than Extension recommended rates, yet the product label legally allows for higher rates. The general belief among research scientists and company cooperators is that consumer rates must be reduced to allow for inevitable over application by consumers. It seems hypocritical to concede that over application of any herbicide is a breach of federal law with a concomitant assumption that homeowners will over apply consumer products.  The use of PECs to pick consumer products is a first step to improving consumer product effectiveness for Virginians. In subsequent PMG revisions, the concept of consumer product rates will be further evaluated.