Effect of Nitrogen and Potassium Fertilization on Growth, Yield and Alkaloidal Content of Periwinkle (Catharanthus roseus G. Don)

摘要

Two field experiments were conducted at the farm of Saft El-Laban, Giza, Egypt, during two successive seasons (2005 and 2006) to study the effect of nitrogen (N) and potassium (K) fertilization on growth, yield and alkaloidal content of periwinkle (Catharanthus roseus G. Don). Periwinkle seedlings were transplanted from the nursery to a permanent field in April in both seasons. The trials included three doses of N (50, 100 and 150 Kg/fed (4200 m~2). as ammonium nitrate) and three doses of K (25, 50 and 75 Kg/fed as potassium sulfate) and their combinations. Plant height (cm), number of branches per plant, fresh and dry weights of plant, as well as the herb yield were determined. These applications produce a significant increase in all the differentcharacters under investigation. The high level of both N and K resulted in the highest values of all parameters. The yield of total C. roseus alkaloids under different fertilization treatments was determined with TLC densitometry analysis, where the highest percentage were recorded in plants fertilized with 150 kg/fed of N and 25 kg/fed of K. Special attention had been paid in this paper to the indole alkaloids, specifically vincristine and vinblastine.