Effect of cultural practices and environmental conditions on yield and quality of herbal plants: Prospects leading to research on influence of nitrogen fertilization, planting density and eco-physiological parameters on yield and quality of field-grown bush tea (Athrixia phylicoides DC.)

Abstract

Herbal plants are grown in diverse regions of varying climates with growth and productivity being influenced by both biotic and abiotic factors. Cultural practices have a significant influence on growth and productivity of these plants. In order to maximize yield and quality of tea as an herbal plant, cultural practices such as fertilization and planting density should be optimized. Fertilization improves growth, total polyphenols, tannins and total antioxidant content of herbal tea. In particular, nitrogen fertilization increases the production of new shoots and the content of nitrogenous compounds, such as free amino acids, which are the major quality indicators of herbal tea. Plant population density also plays role in tea productivity. In addition dense planting may increase the initial yield and revenue. This review discusses the effects of nitrogen fertilization, timing of nitrogen fertilization, planting density and climatic conditions on growth and productivity of herbal teas and other medicinal plants.   Key words: Fertilization, light intensity, planting density, tea quality, temperature.