Development of a sustainable cultivation protocol for Artemisia afra in the Western Cape

Abstract

In Africa, the substantial demand for medicinal plants, predominately sourced from wild populations, exerts pressure on natural habitats. Although species such as Artemisia afra Jacq., ex Willd are extensively utilized, conservation measures for various species are either limited or proven inadequate. Additionally, research efforts have had limited impact on farmers and users of medicinal plants, primarily due to minimal stakeholder engagement, as most studies are conducted in controlled settings. The current production levels of medicinal plants through commercial farming are insufficient to meet the trade demand and modern farming technology alone cannot address the world’s pressing healthcare needs. Therefore, engaging local communities is essential for the preservation of biodiversity conservation and the promotion of sustainable cultivation techniques. This study aimed to develop and implement cost-effective organic cultivation techniques to optimize plant growth and metabolite content of Artemisia afra in the Western Cape. Additionally, investigated traditional healers willingness to adopt these cultivation practices and utilize raw materials produced by small-scale farmers. Ultimately, the study aimed to equip traditional healers and small-scale farmers with essential medicinal plant cultivation techniques, fostering sustainable agricultural practices. In chapter 1, the conceptual background and scientific rationalizations of the study are presented. Chapter 2 focused on assessing the effects of different organic amendments on the growth, secondary metabolites, and antioxidant properties of A. afra, to establish a sustainable and feasible cultivation approach. Four organic amendments were selected in response to the increasing demand for organically cultivated medicinal plants. These included vermicompost, mushroom compost, poultry and kraal manure, mixed with coarse river sand at a ratio of 70% sand and 30% organic amendments. The results highlighted a significant improvement in growth parameters with the use of poultry manure, likely due to its rich nutrient content compared to other organic amendments studied. Poultry manure also exhibited the highest concentration of secondary metabolites (polyphenols and flavonols) and antioxidant activities in A. afra, including (ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Trolox equivalent antioxidant capacity (TEAC). Furthermore, there was a strong correlation between secondary metabolites and antioxidant activity, suggesting that the presence of secondary metabolites influenced the overall antioxidant activity of the plant. Substantially, the application of poultry manures positively influenced the growth, secondary metabolites and antioxidant activities of A. afra. Chapter 3 explored the readiness of traditional healers in the Western Cape to engage with cultivated medicinal plants, their views on conservation efforts, and identify the species they prioritize for conservation. A total of 75 traditional healers were randomly selected to complete semi-structured questionnaires, and two workshops were organized to promote collaboration among different stakeholders (traditional healers and researchers). The results indicated that 52% of the respondents depend on the collection of medicinal plants as their main source of income, while 92% noted that the sale of these plants contributes to their overall earnings. The research identified 64 medicinal plant species that are frequently used, with Artemisia afra being the most prevalent, followed by Rhoicissus digitata and Silene undulata. A significant majority (96%) expressed a strong interest in the cultivation of medicinal plants, and 66.7% recognized the decline of certain species. Furthermore, an overwhelming 98.7% of participants reported using and selling A. afra, underscoring its high demand. Respondents identified 44 medicinal uses for A. afra, with common applications including treatments for respiratory and digestive issues, pain relief, immune booster, and various ritualistic practices. Chapter 4 presented a training workshop designed to enhance the propagation skills of traditional healers and small-scale farmers. Conducted at the Cape Peninsula University of Technology, the workshop attracted 58 participants who took part in practical training sessions covering seed sowing, vegetative propagation, transplanting, composting, and soil preparation. Evaluations conducted after the workshop indicated that all participants deemed the training pertinent, with 71.7% reporting a boost in their confidence regarding the cultivation of medicinal plants. A significant number of small-scale farmers expressed a desire to create nurseries for indigenous medicinal plants, highlighting the workshop’s effectiveness in promoting sustainable cultivation methods. The collaboration and engagement of a diverse array of stakeholders, including researchers, small-scale farmers, and traditional healers, facilitated the exchange of knowledge and reinforced collaborative initiatives. This study emphasized the critical necessity for conservation-oriented programs and community driven cultivation approaches to mitigate dependence on wild harvesting. By merging scientific inquiry with traditional practices, the results lay the groundwork for sustainable production of medicinal plants, thereby ensuring enduring advantages for both ecological preservation and the livelihood of local communities.