S.G. Sparg

Cultivating the Medicinal Plant Merwilla Natalensis as a Crop A Small-Scale Farming Approach

The indigenous South African medicinal plant, Merwilla natalensis, was cultivated in two different geographical regions with different climatic conditions. Bulbs grew exponentially reaching approximately 300 g fresh weight after 24 months in the field. Plants were cultivated under three different treatments. The results suggested that bulb growth was not dependent on additional fertilizer (organic or inorganic) or irrigation, as there were no significant differences (p=0.05) in the average dry weight of the bulbs grown under the three treatments. Irrigation had an effect on the growth of young plants, preventing senescence and causing the plants to grow during the dormancy period. Bulbs started flowering after two years of growing in cultivated fields. Bulbs seemed to flower more when irrigated.

The effect of cultivation and plant age on the pharmacological activity of Merwilla natalensis bulbs

Merwilla natalensis bulbs were cultivated at two different sites under different treatments. Bulbs were harvested every six months for a period of two years and were tested for antibacterial, anti-inflammatory and anthelmintic activity. The cultivation treatments had no significant effect (P ≤ 0.05) on neither the antibacterial activity, nor the anti-inflammatory activity. However, the age of the bulbs had a significant effect against the test bacteria and on the inhibition of prostaglandin synthesis by COX-1, with activity decreasing as the bulbs matured. The cultivation treatments had a significant effect on the antihelmintic activity of bulbs cultivated at the Fort Hare site. Results suggest that irrigation might increase the antihelmintic activity of the bulbs if cultivated in areas of low rainfall. The age of the bulbs at both sites had a significant effect on the antihelmintic activity, with activity increasing with plant maturity.