Department of Biology, University of Aveiro, Aveiro, Portugal.
CESAM (Centre for Environmental and Marine Studies), University of Aveiro, Aveiro, Portugal.
Ecotoxicology. 2023 Jan;32(1):102-113. doi: 10.1007/s10646-023-02619-w. Epub 2023 Jan 18.
The use of fungicides in agriculture has been playing a role in the enhancement of agricultural yields through the control of pathogens causing serious diseases in crops. Still, adverse environmental and human health effects resulting from its application have been reported. In this study, the possibility of readjusting the formulation of a commercial product combining azoxystrobin and tebuconazole (active ingredients - AIs; Custodia®) towards environmentally safer alternative(s) was investigated. Specifically, the sensitivity of non-target aquatic communities to each AI was first evaluated by applying the Species Sensitivity Distributions (SSDs) approach. Then, mixtures of these AIs were tested in a non-target organism (Raphidocelis subcapitata) denoting sensitivity to both AIs as assessed from SSDs. The resulting data supported the design of the last stage of this study, where mixtures of those AIs at equivalent vs. alternative ratios and rates as in the commercial formulation were tested against two target fungal species: Pyrenophora teres CBS 123929 and Rhynchosporium secalis CBS 110524. The comparison between the sensitivity of non-target aquatic species and the corresponding efficacy towards target fungi revealed that currently applied mixture and rates of these AIs are generally environmentally safe (antagonistic interaction; concentrations below the EC for R. subcapitata and generally below the HC for aquatic non-target communities), but ineffective against target organisms (maximum levels of inhibition of 70 and 50% in P. teres CBS 123929 and R. secalis CBS 110524, respectively). Results additionally suggest a potentiation of the effects of the AIs by the other formulants added to the commercial product at tested rates. Overall, this study corroborates that commercial products can be optimized during design stages based on a systematic ecotoxicological testing for ingredient interactions and actual efficacy against targets. This could be a valuable pathway to reduce environmental contamination during transition to a more sustainable agricultural production.
农业中杀菌剂的使用通过控制导致作物严重疾病的病原体，对提高农业产量发挥了作用。然而，由于其应用，已经报道了对环境和人类健康的不利影响。在这项研究中，调查了调整含有嘧菌酯和戊唑醇（活性成分-AI；Custodia®）的商业产品配方的可能性，以寻找更安全的替代方案。具体来说，首先应用物种敏感性分布（SSD）方法评估非靶标水生群落对每种 AI 的敏感性。然后，在非靶标生物（新月形藻）中测试这些 AI 的混合物，新月形藻对 SSDs 评估的两种 AI 均敏感。所得数据支持了本研究最后阶段的设计，即在商业制剂中以与替代方案等效的比率和速率测试这些 AI 的混合物，以对抗两种靶标真菌：禾谷镰孢菌 CBS 123929 和禾旋孢腔菌 CBS 110524。将非靶标水生物种的敏感性与对靶标真菌的相应功效进行比较表明，目前应用的混合物和这些 AI 的比率通常对环境是安全的（拮抗相互作用；浓度低于新月形藻的 EC，通常低于水生非靶标群落的 HC），但对靶标生物无效（对禾谷镰孢菌 CBS 123929 和禾旋孢腔菌 CBS 110524 的最大抑制水平分别为 70%和 50%）。结果还表明，在测试的比率下，商业产品中添加的其他配方成分增强了 AI 的效果。总体而言，这项研究证实，在设计阶段，可以根据成分相互作用的系统生态毒理学测试和对靶标的实际功效来优化商业产品。这可能是减少向更可持续农业生产过渡过程中环境污染的有价值途径。
