Unveiling the Allelopathic Potential of Wedelia Leaf Extract as a Bioherbicide against Purple Nutsedge: A Promising Strategy for Sustainable Weed Management

Weed management is a crucial aspect of sustainable agriculture. In this study, we investigated the allelopathic potential of wedelia (Wedelia trilobata L.) leaf extract as a bioherbicide against purple nutsedge (Cyperus rotundus L.). The experiments were carried out through greenhouse experiments using a completely randomized design (CRD) with four replications. Five different concentrations were evaluated: C10 (10 wedelia extract concentration), C20 (20 wedelia extract concentration), C40 (40 wedelia extract concentration), C+ (92 mg L−1 of gallic acid), and C− (aquadest). Allelochemicals present in the wedelia leaf extract inhibited plant height, shoot number, leaf number, leaf area, root area, and total root length. The fresh weight, dry weight, and photosynthetic pigments decreased with increasing wedelia leaf extract concentrations. Malondialdehyde contents were highest when C40 was used. Additionally, peroxide activities decreased at the highest wedelia leaf extract concentration, indicating the failure of the plant’s antioxidant defense mechanism. The decrease in growth, photosynthetic pigment, and antioxidant activity indicates that wedelia leaf extract may be able to help control the growth of purple nutsedge. The results of this study could contribute to the development of a new cropping system based on the use of wedelia as a bioherbicide for sustainable agriculture.