Submitted to: Extension Circular
Publication Type: Proceedings
Publication Acceptance Date: December 1, 2003
Publication Date: January 20, 2004
Citation: Anderson, B.A., Reding, M.E., Klein, M.G., Krause, C.R. 2004. Ir-4 Ornamental Trials Conducted by USDA-ARS in Ohio: 2003. Extension Circular. 193:130-134. Technical Abstract: A shortage of registered pest control products for the ornamental industry is an ongoing problem. The Interregional Research Project No. 4 (IR-4) is designed to address this problem by funding pesticide trials to obtain the data needed by the EPA for label expansion and registration of new products. The Application Technology Research Unit (ATRU), USDA/ARS, in Wooster, Ohio, conducts 50 to 60 trials per year for the IR-4 program. During the 2003 growing season, fungicide, herbicide and insecticide trials were conducted in greenhouse, field and container sites. Herbaceous perennials, woody ornamentals, trees and shrubs were included in the tests. Each test included untreated control plants and three pesticide application rates: 1X (the rate recommended by the manufacturer), 2x and 4x with a minimum of four replications of each. Plants were rated for phytotoxicity and efficacy. Most trials showed no phytotoxicity, although the herbicide Dithiopyr (Dimension ultra WSP) caused severe stunting on two plant species, Impatiens and Veronica along with necrosis on the Veronica. Efficacy data was obtained for the fungicide test using Bacillus licheniformis SB 3086 for control of phytophthora root rot on Aster x Frikartii in the greenhouse. During the course of the test, all control plants died from phytophthora root rot, while all treated plants remained healthy. Data was also obtained from a container test using the insecticide thiamethoxam (Flagship) for control of oriental beetle (OB) larvae (Anomala orientalis). The untreated plants were heavily infested (mean 22.5 live grubs), the recommended rate had a significant reduction of grubs (86.7%) and the 2x and 4x rates had no surviving grubs.