Dear Editor,

Fungicide treatment has a profound effect on controlling plant pathogens in modern agriculture, however, it also carries the risk of undesirable outcomes. For decades, scientists have been concerned about the harmful impacts of heavy metals like copper (Cu) on crop performance and soil microorganisms. Use of various copper fungicides, like Bordeaux mixture, have been a component of conventional agricultural practices to control fungal and bacterial pathogens, especially in vineyards, tea gardens, or fruit tree orchards [9, 10]. This treatment increases the accumulation of high levels of Cu in surface soils, and despite the critical role of Cu as an essential trace element in wide biological and metabolic processes, it becomes toxic to plants when applied at high levels [4]. The regular application of copper fungicides has also been linked to affecting microbial communities at the levels of diversity [8], population structure [2], abundance, and growth [1, 3]. Understanding the undesired effects of fungicides on microorganisms’ beneficial activities is therefore important for evaluating the hazards associated with the fungicide used in agriculture. Yet, the effects of copper fungicide on full microbial communities remains relatively understudied, especially in tea plants. Thus, we herein explored the influence of Bordeaux mixture under different management regimes (raking or without raking leaf litter) on microbial communities of root, bulk soil, and rhizosphere compartments of tea plants planted in a ten-year-old tea garden. We provided insights into the ecological consequences of tea management practices that might help to identify specific fungicide treatment regimens, environmental characteristics, and microbial community members to minimize the negative environmental outcomes and optimize the positive anti-pathogen aspects of fungicide treatment.

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