Effects of Planting Densities on Growth Characteristics and Curcumin Constituents of Curcuma longa L.
Background : Curcuma longa L., is a very famous spice and medicinal herb in several countries of the world. Curcumin and volatile oils of C. longa improve hepatic and renal functions, and could be used against biliary disorders, diabetic and hepatic disorders. This medicinal plant was introduced for the regional promotion, Jeollanam-do, as the subtropic area in Korea. In the present study, the plant was introduced to the Jeollanam-do region of Korea with the aim to determine the optimal planting densities for growth characteristics, yield and curcumin contents which have not been reported up until now. Methods and Results : The field experiment was conducted at the experimental farm of Division of Traditional Korean Medicine Resource, NIKOM, Jangheung-gun, Jeollanam-do, Korea. The seedstock was planted at 40×20cm, 40×30cm and 40×40cm spacing with 3 replications. Nine plants were selected randomly for observations on growth characteristics such as plant height, stem diameter, leaves number, leaves area and to dry weight at days after transplanting (DAT) 90, 120 and 150. The dried samples of plant were stored in air tight polythene bags at room temperature for HPLC analysis of curcumin, which was undertaken following standard procedures. Top plant growth was observed in the 40×30cm planting density of C. longa, plant height, leaves number, leaves area and day shoot weight were larger than in the other treatments. Root length, root diameter and supporting roots of underground part were increased as planting density was wide, and dry root weight was increased in 40×30cm. However, yield and curcumin constituent was highest each 294 kg/10a and 68.7 mg/g in the planting density of 40×20cm. Conclusion : Based on the results of this study, planting density of 40×20cm is the most suitable in the cultivation and curcumin constituents of C. longa.