The roots of Platycodon grandiflorum has been widely used as a crude drug or a food stuff. Unfortunately, the output and the quality is not regular and highly dependent on the cultivation area and cultivation method. Therefore, seedling cultivation study of this plant under structure with various fertilizer supply was performed. As a result, significant big difference between ammonia nitrogen and nitrate nitrogen content was shown in the root at seedling stage while the difference was not significant in the aerial parts. Fresh weight of the root (7.73 g plant-1) was higher in the group treated with three major nutrients (N, P and K) than in those treated with three major nutrients and calcium or magnesium or both calcium and magnesium, and non-treated group (2.69 g plant-1). Total nitrogen content was recognized to be significantly correlated with root weight, plant height, number of leaves and weight of aerial parts. Ammonium nitrogen content was more correlated the growth of P. grandiflorum than nitrate nitrogen. For phosphoric acid, significant correlation was also shown with the four growth factors.

Carrots (Daucus carota L.) are consumed as an important dietary source of provitamin A including β-carotene, α-carotene and lutein. An HPLC method was applied to determine the content of the carotenoid composition in carrot cutivars cultivated in Korea. HPLC analyses were carried out with five carrot cultivars (Socheon-5-chon, Hongsim-5-chon, Myeongju-5-chon, Seonhongbom-5-chon and Betarich) sown at April, 2007 and six cultivars (Yeoreum-5-chon, Hanyeoreum-5-chon, Sinheukjeon-5-chon, Bibariheukjeon, Manina and Betarich) sown at August of the same year. In general, the former varieties are not used for the sowing at summer because of their bolting (growth of floral axis). The former and the latter carrots were harvested after 110 and 96 days from seeding, respectively, and the carotenoids were extracted with acetone after freeze-drying. The amount of α-carotene (117.7∼205.3 μg/g・DW) was similar to that of β-carotene (113.1∼189.6 μg/g・ DW) for the carrot cultivars sown at spring, while the content (46.2∼71.1 μg/g・DW) was about a half of β-carotene content (92.5∼140.2 μg/g・DW) for the latter cultivars. In addition, the average content of lutein (25.2 μg/g・DW) in the former cultivars was eight times higher than that in the latter cultivars (3.1 μg/g・DW). Among the spring cultivation types, Socheon-5-chon and Myeongju-5-chon showed higher amount of α-carotene and β-carotene, while the higher amount was determined in Yeoreum-5-chon and Sinheukjeon-5-chon among the autumn cultivation types. Validation of the HPLC-DAD method showed good linearity (r2 > 0.997) of the three compounds analyzed in a wide concentration range (0.025∼20 μg/ml). The R.S.D. values for intra-day and inter-day precision were less than 19.2% and the mean recovery of each compound was 85.4∼104.7%.