Articles
NUTRIENT AND WATER MANAGEMENT FOR MEDICINAL AND AROMATIC PLANTS
Besides climatic conditions of the growing site it are edaphic factors which are of particular importance.
As for plant production in general, it likewise is true for the production of medicinal and aromatic plants that the main interest so far has been taken in increasing yields to be achieved with the aid of fertilization and irrigation.
Though, for such crops, the production of secondary plant substances is predominant, little is known yet on secondary metabolism as influenced by plant nutrition, or water supply.
Starting from reviews on the influence of irrigation (Penka, 1978) and fertilization (Ruminska, 1978) on yield and contents of active principles of medicinal and aromatic plants, this paper describes recent results and the actual state of knowledge in this field.
Apart from edaphic factors, that are decisive for drug yield, it is to be concluded that the above mentioned factors take a modifying effect on plant development.
This effect on the biogenesis of secondary plant substances, and thus on the quality of the plant material, mostly is an indirect one (essential oils, glycosides; see Franz, 1981), more seldomly a direct one (alkaloids; see Nowacki, 1976). Contradictory results achieved by different authors in general may be attributed to incomparableness of experimental conditions and harvesting dates, or to lack of knowledge on the ontogenesis of the substances in question.