Test No. 227: Terrestrial Plant Test: Vegetative Vigour Test

         This Test Guideline is designed to assess effects on vegetative vigour of terrestrial plants following above-ground exposure by general chemicals, biocides and crop protection products.          The test can be conducted in order to determine the dose-response curve, or at a single concentration/rate as a limit test (range finding test is carried out depending on the results) according to the aim of the study. Plants are grown from seed usually to the 2- to 4- true leaf stage. Test substance is then sprayed on the plant and leaf surfaces at appropriate rate(s). After the application, the plants are evaluated against untreated control plants for effects on vigour and growth at various time intervals through 21 - 28 days from treatment. This study includes measurement of biomass of surviving plants (dry or fresh shoot weight, shoot height), visible detrimental effects on different parts of the plant, visual phytotoxicity and mortality (daily during the study) Appropriate statistical analysis are used to obtain an effective concentration ECx or an effective application rate ERx for the most sensitive parameter(s) of interest. Also, the no observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) can be calculated in this test.      