Effectiveness of Betel Leaf Extract (Piper betle L.) on the Growth of Rice Plant Pathogenic Bacteria: Critique of Biological Approaches to Plant Disease Control

Abstract

Bacterial Leaf Blight (BLB), caused by Xanthomonas oryzae pv. oryzae, remains one of the most destructive diseases affecting rice cultivation in Southeast Asia, with severity levels reported as high as 92% and yield losses reaching 50–70%. Conventional chemical pesticides are often effective but pose environmental and health risks, prompting interest in biological alternatives. This study investigates the effectiveness of betel leaf (Piper betle L.) extract as a biological control agent through in vitro and in vivo experiments. Results demonstrate that the extract exhibits significant antibacterial activity, with inhibition zones increasing alongside concentration levels and disease incidence reduced by up to 40% under field-simulated conditions. Bioactive compounds, particularly phenols, flavonoids, and essential oils, were identified as major contributors to cell wall disruption and bacterial growth suppression. Despite its promise, the approach faces challenges such as inconsistent phytochemical content, limited compound stability, and higher production costs. These findings emphasize the potential of betel leaf extract as an eco-friendly alternative, while highlighting the importance of standardization, technological innovation, and policy support to ensure sustainable application in modern rice farming systems.