Effect of Fertilizer and Plant Age on Diosgenin Yield in <I>Costus speciosus</I>

Abstract

Costus speciosus is a high potential crop to produce as a source of diosgenin, a substance for various medical used. Important informations for cultivation are however very lacking. In this experiment growth habitat of plant as well as diosgenin accumulation as affected by plant age, developmental stage and nutrition were studied. The results revealed that Costus is a perennial plants with a constant life cycle of germination from rhizome and dormancy every year. Plants responded very reluctant to NPK-fertilizers applied. However, growth and dry weight of rhizome increased with plant age and were the highest in the third year. Diosgenin accumulation in rhizome was 0.19-0.45% at flowering stage and decreased to 0.05-0.10% at dormancy. The total yield of diosgenin per cultivated area remained the highest at flowering stage in the second year.