PARENT SESSION
WP6 - Agrochemicals
Chair: Giddings, Jeff1, 1 The Cadmus Group, Marion, MA
2:10 PM to 5:30 PM - Wednesday, 20 November 2002
Room Ballroom B
(617) Phytotoxicity of low-dose, high-potency herbicides to agronomic crops and related species.
Knuteson, Sandra*,1, Klaine, Stephen1, 1 Clemson University, Pendleton, SC, USA
ABSTRACT- Low-dose, high-potency herbicides are characterized as herbicides, which are very affective at application rates of less than 0.6 kg/ha. Even though these herbicides are used at lower rates than other herbicides, they still may pose environmental risks to non-target plant species due to their high potency. Recently, the protection of non-target plant species, such as native plants, as well as endangered and threatened species, has become an important issue in the area of pesticide registration. Pesticide registration is based on toxicity tests using both aquatic and terrestrial flora; however, data comes from research on agricultural crop species such as corn or carrot for extrapolation to terrestrial plants and duckweed or algae for aquatic plants. The Office of Prevention, Pesticides and Toxic Substances (OPPTS), US Environmental Protection Agency (EPA), has developed standard guidelines for these toxicity tests including both terrestrial and aquatic exposure scenarios for flora and fauna. This research asks the question: are non-target plant species being protected under this system using agricultural crops as surrogate test species? Standard phytotoxicity tests, developed by OPPTS, were used to compare the sensitivities of current plant test species with native plant species. Preliminary results suggest that taxonomically related species might have different sensitivities to herbicides, even within the same species. Results from standardized phytotoxicity tests with agronomic species may not adequately protect non-target species, suggesting that a wider variety of plant species may need to be used for pesticide registration.
Key words: phytotoxicity, sulfonylurea, non-target plants, pesticide registration