Evaluation of phytotoxicity testing: Assessing the effects of herbicides on non-target plants using microcosm tests.

摘要

Intensification of agriculture and the corresponding increase in herbicide use has led to concern regarding the effects these chemicals may have on non-target plants of agroecosystems. Current pesticide registration guidelines are focused on testing crop species grown singly in pots under greenhouse conditions and may not provide adequate measures of protection to non-crop species. The main objective of this study was to compare the response of terrestrial and wetland plants to glyphosate and atrazine when grown singly in pots versus under different microcosm conditions. Greenhouse microcosms were generally more sensitive than single species tests. Plants grown for an extended test period or in semi-natural field conditions were generally less sensitive. Sensitivity was found to be dependent on interactions between species and test conditions. Stomatal conductance and the chlorophyll fluorescence parameter, Fv/Fm were found to be effective non-destructive indicators of herbicidal damage and may provide useful additional information in phytotoxicity testing.