Toxicity of Four Commercial Fungicides, Alone and in Combination, on the Earthworm Eisenia fetida: A Field Experiment.

Abstract

This study investigated the sub-lethal effects of four commercial fungicides-two foliar (Amistar^®Xtra and Mirador^®) and two ear fungicides (Prosaro^® and Icarus^®)-applied alone and in combination to wheat crops on caged earthworms (Eisenia fetida). We measured biomarkers that included detoxification responses (glutathione S-transferase, GST), oxidative stress levels (lipid peroxidation, LPO, and catalase, CAT), DNA damage (comet assay), energy reserves (lactate dehydrogenase, LDH), and immune response (lysozyme activity, LYS). The absence of significant differences in catalase and lipid peroxidation levels suggested no oxidative stress due to fungicide exposure. However, the foliar fungicide Amistar^®Xtra induced the highest GST activity and DNA fragmentation, suggesting synergistic effects between its active ingredients and undisclosed co-formulants. Similar effects observed with the Amistar^®Xtra-Prosaro^® mixture confirmed the greater toxicity of Amistar^®Xtra. This study provides novel insights into the sub-lethal effects of single and combined commercial fungicides on a standard toxicity test organism, shedding light on the ecological implications of fungicide use in agroecosystems and reinforcing the need for pesticide reduction.