Effect of Soil Moisture Content and Irrigation Intervals on Sennoside Content of Alexandrian Senna (Cassia acutifolia L.)

Abstract

A field experiment was conducted for two consecutive seasons (2003 and 2004) in the demonstration farm of the Faculty of Agricultural Studies, Sudan University of Science and Technology at Shambat, Sudan to study the effect of irrigation intervals and quantity of water on sennoside content of Alexandrian senna leaves and pods. Three levels of soil moisture content (50%, 75%, and 90% field capacity) and three irrigation intervals (7, 10, and 14 days) were used for the determination of sennoside content (Sennoside A and B) of Alexandrian senna (Cassia acutifolia L.). Data were collected on leaf yield, pods yield, percentage of sennoside content of pods and leaves at flowering and after fruiting stages. Pod sennoside content was 5.35%, 5.41% and 5.46% during the first season and 5.07%, 5.43% and 5.35% during the second season for intervals of 7, 10, and 14 days, respectively. Results showed that the highest quantities of water decreased the percentage of sennoside content in leaves and pods. The sennoside content of leaves at the flowering stage was 2.56%, 2.63% and 2.7% during the first season, and 2.49%, 2.52% and 2.51% during the second season. Pod sennoside content was 5.48%, 5.46 % and 5.28% during the first season, and 5.51%, 5.32% and 5.04% during the second season for quantities of 50%, 75%, and 90% field capacity, respectively. It was concluded that lower quantities of water (50% field capacity) increased the leaf sennoside content significantly than that of the higher field capacity (95%).