Ecotoxicological characterisation of a mycoherbicide mixture isolated from the fungus Ascochyta caulina

BACKGROUND:RecentstudieshavehighlightedthepossibilityofusingamixtureofthreefungaltoxinsproducedbyAscochyta caulina as a bioherbicide to control noxious weeds. However, to assess the commercial potential of this new bioherbicide, it is necessary to increase knowledge regarding the environmental behaviour of these toxins, and particularly their effects on non-targetorganisms.Anegativeecotoxicologicalprofileofthispotentialbioherbicidecouldeventuallyhinderitsregistration. RESULTS: In this study, acute and chronic effects of the A. caulina toxins (ACTs) on non-target organisms were evaluated in the laboratory. The (96h) calculated algal ErC50 and NOEC were 142.7 and 1000 and ≥250mgkg −1 soil respectively. CONCLUSIONS: The present study has provided baseline information needed to assess the potential hazard of the fungal toxins of A. caulina. In particular, the acute and chronic effects on aquatic (algae, Daphnia and fish) and terrestrial organisms (earthworms) have been highlighted. Finally, a comparison of the inherent toxicity of ACTs with other synthetic herbicides has shown comparative ecotoxicity of the tested mixture. c � 2012 Society of Chemical Industry