Study on the Occurrence Characteristics and Control Techniques of Gummosis in Zanthoxylum bungeanum on the Qinghai Plateau

As an important economic forest tree species on the Qinghai Plateau, the outbreak of gummosis in <i>Zanthoxylum bungeanum</i> seriously threatens the sustainable development of the regional industry. This study is the first to clearly identify <i>Fusarium equiseti</i> as the pathogen responsible for the gummosis disease of <i>Z. bungeanum</i> on the Qinghai Plateau. To identify effective control agents, based on the indoor virulence screening of 13 fungicides, it was found that 80% ethylicin exhibited the strongest inhibitory activity against the pathogen (EC₅₀ = 0.396 μg/mL). Transmission electron microscopy revealed that ethylicin acts through multi-target effects, including disruption of cell membrane integrity and induction of mitochondrial cristae disintegration. Field trials have shown that the control efficacy of 80% ethylicin alone reaches 93.10%, and when combined with rhamnolipid in a 1:1 ratio, the control efficacy remains at 85.77% even when its dosage is reduced by 50%. Additionally, a novel Xuan paper imprint method was developed for precise quantification of lesion areas in the field. This study demonstrates the potential of ethylicin as a core fungicide for controlling <i>Z. bungeanum</i> gummosis, offering a scientific basis for integrated disease management in plateau ecosystems.