Effect of soil moisture on the yield and quality of rhizome in turmeric {Curcuma longa)

摘要

Turmeric (Curucuma longa L.) includes many functional components in the rhizome, and the most important ingredient is curcumin, a yellow pigment, which has antioxidant and anti-bacterial properties. Plant growth, rhizome yield and curcumin content change depending on various environmental factors. We examined to evaluate the effects of relative soil moisture on the yield and curcumin content of turmeric rhizome. The average soil moisture of the control plot during the cultivation period was 19.5%. Thevalues in the high and the low moisture plots were 23.4 % and 18.8 % respectively. As a result of measuring at 225days after planting, values of total leaf area and the rhizome growth rate in the high moisture plot were 1.8 times compared with the control plot. Curcumin content per rhizome dry weight was highest in the control plot, though the difference was statistically non-significant. On the other hand, the curcumin content per plant was significantly higher in the high moisture plot, 267.9 mg/plant.