Diversity and harmfulness of weed species in citrus orchards in the Three Gorges Reservoir Region

To determine the diversity and harmfulness of weed species in citrus orchards in the Three Gorges Reservoir Region, 255 quadrats in 51 citrus orchards were investigated using a five-point pattern. A total of 185 weed species were found, belonging to 146 genera in 53 families, of which Compositae, Gramineae, Polygonaceae, Apiaceae, and Amaranthaceae were the most dominant. We identified 15 species (Alternanthera philoxeroides, Digitaria cruciata, Cyperus rotundus, Bidens biternata, and others) as priority targets for control. In addition, it was found that the citrus orchard weed communities showed a clear trend of succession toward climax. Therefore, the main objective of weed control in citrus orchards should be to mitigate or inhibit the succession of climax species, and the regional control strategy should be based on interspecies relationships. This study provides an important reference for weed control and optimal management of citrus orchards in the Three Gorges Reservoir Region.