Stem rots caused by Rhizoctonia solani and Sclerotinia sclerotiorum have been known as devastating diseases in balloon flower plants. Antifungal activities of four fungicides, azoxystrobin, polyoxin B, trifloxystrobin and validamycin A were evaluated in vitro, showing effective suppression with mycelial growth of the fungal isolates on PDA media. Efficacies of the four fungicides were also demonstrated in stem tissues of balloon flower plants against R. solani and S. sclerotiorum. A commercially available Bacillus subtilis strain Y1336 was tested in terms of antagonistic biological control of stem rot disease of balloon flower plants. The bacterial strain revealed its antifungal activities against R. solani and S. sclerotiorum demonstrated by dual culture tests using paper discs and two plant pathogenic fungi on PDA media, as well as by plant inoculation assay, indicating that this antagonistic bacterial strain can be incorporated into disease management program for balloon flower stem rot diseases together with the four chemical fungicides.

: This study was carried out in order to survey the soil physico-chemical, morphology and content of saponins of 5 year-old Platycodon grandiflorum radix from different areas in Gyeongnam. Soil physical properties was showed 1.01-1.29 of bulk density of soil and soil hardness was increased with increasing soil depth, especially below the 30 ㎝, however it was maintained or small increased below the 40 ㎝. T-N and OM contents of top soil were highest at Geochang as 0.27% and 56.9 g/kg, respectively, compared to other areas. The root length was longer at Kimhea and Geochang as 33.8 and 33.7 ㎝, respectively, and fresh weight was heavy at Geochang as 208.5 g. The contents of saponin of P. grandiflorum radix was higher in fine root compare to main root. By region, content of saponins of P. grandiflorum radix were higher at Hapcheon than other area. Mg content was highly negatively correlated at p < 0.01 with platycodin D3, deapioplatycodin D, platycodin D, and deapioplatycodin D (-0.499**, -0.433**, -0.421**, -0.511** respectively). These results suggest that no-fertilized Mg effected on the improvement of saponin contents in P. grandiflorum.