Indigenous plant-based disease management practices among smallholder farmers in Madibeng Local Municipality, South Africa

Annually, food commodity losses are reported worldwide due to pests and diseases affecting plants. Due to the high cost, most smallholder farmers cannot afford chemical treatments and often rely on botanical extracts as an alternative. In response to United Nations Sustainable Development Goals (UN SDGs) including #1 (no poverty), #2 (zero hunger), #3 (good health and well-being) and #15 (life on land), this study explored the use of locally sourced botanicals for the management of plant diseases in Madibeng Local Municipality, South Africa. An ethnobotanical survey was conducted from October to December 2024 using non‑probability purposive and snowball sampling design that resulted in the recruitment of 32 consenting participants. Data derived from the survey were subjected to descriptive statistical and ethnobotanical analyses. The participants identified 14 plants belonging to 9 families that were used to managing various diseases in crops. Amaryllidaceae and Fabaceae were the most represented families, each represented by three (3) plant species. The most mentioned plant species were Capsicum annuum L., Allium cepa L., and Aloe davyana Schönland, with associated relative frequency of citations of 0.63, 0.19, and 0.19, respectively. Fruit (35%) and leaves (28%) were the most used plant parts in the preparation of remedies to manage different diseases such as bacterial leaf spot, downy mildew, and powdery mildew, which were common, affecting crops and causing production losses. Given that data collection was limited to three settlements within the Madibeng Local Municipality; the results may not be broadly generalised to different agroecological zones across South Africa. Nevertheless, the current findings highlighted the important role of botanicals in managing plant diseases and their impact on addressing food production and food insecurity. For downstream safety and efficacy applications, there is need for scientific evaluation of these plants for possible integration into contemporary agricultural practices.