Chapters authored
Effects of pH and Phosphorus Concentrations on the Chlorophyll Responses of Salvia chamelaeagnea (Lamiaceae) Grown in Hydroponics
Salvia chamelaeagnea (Lamiaceae) is a slow growing water‐wise evergreen shrub originating from the western province of South Africa. It is an attractive landscape, and S. chamelaeagnea is a medicinal plant. It is important to develop enhanced cultivation protocols that could result in high yield and high‐quality medicinal materials. Chlorophyll is a fundamental part of the light‐dependent reactions of the photosynthesis process. This chapter investigates the effects of four phosphorus concentrations and three pH levels of supplied irrigated water on the production of chlorophyll A, chlorophyll B, total chlorophyll, leaf colour and the nutrient uptake of S. chamelaeagnea grown in hydroponics over an 8‐week period at the Cape Peninsula University of Technology. The treatments of pH 4, pH 6 and pH 8 at 31, 90, 150 and 210 ppm of phosphorus were received by 12 groups of plants and were replicated 10 times. The results indicated that at pH 4, P fertilization significantly (P < 0.05) induced a higher chlorophyll production of S. chamelaeagnea grown in hydroponics compared to other pH treatments (pH 8 and pH 6).
Part of the book: Chlorophyll
Prospects of N Fertilization in Medicinal Plants Cultivation
High global demand for plant-derived medicines is threatening the existence of many wild indigenous plant species. However, the high demand of medicinal plants has also created huge business opportunities in commercial farming of medicinal plants. Large-scale production of secondary metabolites by plants and medicinal materials will be crucial in the medicinal plant industry. As commercial cultivation of medicinal plants gains traction among farmers, N fertilizers will be increasingly used to enhance plant growth and yield. Therefore, the implementation of better nitrogen use efficiency is critically important. Excessive use of N can lead to many problems; it is costly, it can cause environmental pollution and its high levels in plant tissues can be toxic to plants, herbivores and humans. This chapter discusses the potential risks, opportunities and setbacks associated with the use of N in cultivation of medicinal plants.
Part of the book: Nitrogen in Agriculture
The Importance of Sceletium tortuosum (L.) N.E. Brown and Its Viability as a Traditional African Medicinal Plant
Sceletium tortuosum is a succulent plant that belongs to the family Mesembryanthemaceae (Aizoaceae). It is indigenous to South Africa, where it is well known by the indigenous people, especially in Namaqualand where the plant is utilized regularly for its medicinal and psycho-active properties. The main alkaloids responsible for these properties are mesembrine, mesembrenine (mesembrenone), and mesembrenol. The potential of the plant to be an alternative supplement in the promotion of health and treating a variety of psychological and psychiatric disorders such as depression and anxiety has stimulated interest in its pharmacological property and possibility of its commercialization. The economic value of indigenous medicinal plants in South Africa is approximately US$60 000 000 or R4 000 000 000 annually. Thus, interest in the knowledge and use of Traditional African Medicinal Plants (TAMP) as well as meeting pharmacological and economic needs of ever-increasing human population has led to the commercialization of traditional African medicines at a fast rate. It was found that S. tortuosum has clear pharmaceutical and economical importance and is one of the only known plants to contain the alkaloids mesembrenone and mesembrine which can be utilized for the promotion of health and/or treating a variety of psychological disorders such as anxiety and depression.
Part of the book: Natural Drugs from Plants
Seed Soaking Times and Irrigation Frequencies Affected the Nutrient Quality and Growth Parameters of Hordeum vulgare L. Cultivated in Hydroponics
The choice of hydroponic systems for fodder production is of great importance to Sub-Saharan Africa and specifically South Africa, considering the current water crisis. This study investigated the impacts of seed soaking times and irrigation frequency on the vegetative and nutritive properties of Hordeum vulgare grown in a hydroponic room. H. vulgare seeds were weighed and soaked in sterile containers filled with 500 mL solution of 20% solution of sodium hypochlorite for 1, 3, 8, 16 and 24 h at room temperature. Once soaked, the seeds were transferred to a hydroponic system and irrigated using flood irrigation. After the 8-day growing period, growth parameters were measured, and samples were oven-dried, pulverized and then subjected to nitrogen and protein analysis. It was observed that shorter soaking time with varied irrigation frequencies had the highest impact on the weight, and nutrient yield of H. vulgare although other growth parameters investigated such as leaf length and root map expansion deviated from this trend under different soaking times and irrigation frequencies. This study revealed that a 1-h pre-soaked treatment was the best for cultivating barley hydroponically. This treatment is recommended for the cultivation of barley as it proved to be beneficial to the farmer in terms of quality yield.
Part of the book: Irrigation and Drainage