Flavonoids from Citrus reticulata: Inhibitory activity against pathogenic fungi and biocontrol potential

The risks of synthetic fungicides propel a shift to biological plant disease control. Attention has been focused on screening plant secondary metabolites for plant-derived pesticides. Flavonoids are abundant and structurally diverse in citrus peels. The co-cultivation of four fungal pathogens with flavonoid extracts from the peels of Citrus reticulata unveiled a substantial inhibitory effect of these compounds, with polymethoxyflavones identified as the primary contributors. The microencapsulated citrus flavonoids using sodium alginate and gelatin showed 60% efficiency against cucumber wilt in potted seedlings, highlighting the potential of citrus flavonoids for biocontrol in field applications.