PARENT SESSION
TA4 Current developments in risk assessment for pesticides
9:00 AM to 12:30 PM, Tuesday, 08 May 2001
Session Chair: M. Streloke
Room 4

(175) Results of Non-target Plant Testing in the Vegetative Vigour Test according to the New OECD Guideline.

Noack, Udo¹, McVean, Kirsten¹, Fiebig, Silke¹, ¹

ABSTRACT- In the new OECD Guideline 208 (draft) the testing of herbicides is regulated. Herbicides will be tested in a multiple rate test to establish the EC50 and EC25 for biomass and visual phytotoxic effects. Due to the intended use of pesticides (pre- or post emergence) 2 different tests will be carried out. The vegetative vigour test assesses the potential effects of post-emergence used pesticides following deposition on the leaves and above-ground portions of plants. The pesticide is sprayed on the plant and leaf surfaces at the 2- to 4-leaf stage. Afterwards the plants are evaluated against the untreated control plants for effects on vigour and growth a various time intervals through 21 days from treatment. Endpoints measured are biomass (fresh or dry shoot weight and shoot height) and visual phytotoxicity rates (e.g. chlorosis, necrosis, mortality, plant development abnormalities, etc.). The measured endpoints show different sensitivity, e.g. effects on the fresh or dry weight are higher than effects on the shoot height. On the other hand no difference was found between the data calculated from the fresh or dry shoot weight determination. Results of herbicides in the non-target plant testing will be presented.

Key words: Non-target Plants, Vegetative vigour test, Herbicides