To determine the optimal fertilizer level of wanggol in southeren areas of Korea, Gwangsan ealy local, the highest yielding variety was grown under nine different fertilezer levels. Yield components such as stem length, number of tillers, stem diameter were the highest at the treatments of fertilizer levels, N-P2O5-K2O=7-2-3 and 9-2-3 kg/10a plots. Dry cortex and medulla yield were the highest at the treatments of N-P2O5-K2O=7-2-3 and 9-2-3 kg/10a fertilizer levels. Judging from the results, an optimum fertilizer level of wanggol seemed to be N-P2O5-K2O=7-2-3 and 9-2-3 kg/10a.

• Byung-Sun Kwon