Study on the Single Toxicity of Five Azole Fungicides for Green Algae

¹ Shaanxi Provincial Land Engineering Construction Group Co., Ltd. China
² Institute of Land Engineering and Technology, Shaanxi Provincial Land Engineering Construction Group Co., Ltd. China
³ Key Laboratory of Degraded and Unused Land Consolidation Engineering, Ministry of Natural Resources China
⁴ Shaanxi Provincial Land Consolidation Engineering Technology Research Center China
⁵ Land Engineering Technology Innovation Center, Ministry of Natural Resources China

^* Corresponding author: 373289543@qq.com

Abstract

Azole fungicides are widely used to control diseases and insect pests of vegetables, fruits and flowers because of their good antibacterial effect and regulating plant growth. However, their extensive use inevitably enters the water environment with rainfall and surface runoff, which leads to potential harm to aquatic organisms. At present, the research on the biological toxicity of azole fungicides mainly focuses on single azole compounds, such as Paclobutrazol, hexaconazole, propiconazole and Difenoconazole. However, the systematic study on the toxic effects of multi-component mixtures of azole fungicides is still very lacking, and it is unable to accurately assess the ecological risk. Therefore, in this paper, five common azole fungicides (imidazole, tebuconazole, triadimefon, tricyclazole and hymexazol) in the environment were taken as target pollutants. Scenedesmus obliquus was used as the toxicity indicator. The mixture system was designed by the equal effect concentration ratio method and linear average ray method. Study the 96h toxicity and interaction of Scenedesmus obliquus under combined stress of azole fungicides. The main research results are as follows:The 96 h toxicity test of five typical azole fungicides to Scenedesmus obliquus was determined by microplate toxicity analysis method. Fitting with Weibull function and taking EC50 as the criterion,the results show that the single toxicity order of the five tested fungicides was:tebuconazole > Triadimefon > oxacillin > Tricyclazole > imidazole.