Search

In August of 2011, a wilting disease of ginseng was observed at Bongwha, Gyeongbuk province, Korea. Affected plants initially show withering symptoms on leaves of ginseng. As the disease progresses, withering leaves spread downward, eventually encompassing the whole plant. Leaves lose vigor but remain pale green. Symptoms of roots were brown, and soft rots characterized by moist and watery decay of the whole ginseng root, which initiated as small brown, water-soaked lesions of hairy roots and enlarged to the entire roots. The causal organism isolated from the infected roots was identified as Serratia plymuthica based on its physiological and biochemical characteristics, by cellular fatty acid composition (GC-FAME), the utilization of carbon sources (BioLog System), and 16S rRNA sequence of the isolated bacterium were 99% homologous to those of Serratia plymuthica strains. Artificial inoculation of the bacterium produced the same brown or soft rot symptoms on the ginseng roots, from which the same bacterium was isolated. This is the first report of bacterial root rot caused by the Serratia plymuthica in ginseng in Korea. Serratia plymuthica has been used as antagonistic microorganism for biological control on several crop plants. But it was proved pathogen of ginseng at humid condition in this study.

Punggi Ginseng Experiment, Gyeongbuk Provincial ATA, YeongJu 750-870, Korea.ABSTRACT : Lime-bordeaux mixture has been used to prevent diseases in the field of ginseng. The purpose of this study isto investigate the efficacy of lime-bordeaux depending on the concentration and treatment time on major diseases of ginsengsuch as Alternaria blight and anthracnose, and to evaluate the root growth of ginseng. Lime-bordeaux caused damage onleaf when it was sprayed on ginseng between April and early May. No difference was found in root growth by sprayinglime-bordeaux mixture between ratio 4-4 and 8-8 ratio in concentration. Plot of 6-6 raito and 8-8 ratio appeared to be sim-ilar efficacy compared to that of practical chemical control. However, the plot of 4-4 ratio showed lower than that of chem-ical control.Key Words : Panax ginseng, Lime-Bordeaux Mixture, Alternaria blight, Anthracnose

Korean ginseng has been used for thousands of years as an important medicinal plant. Lime-Bordeaux mixture (LBM) was made with copper sulfate and quicklime, which was sprayed instead of pesticides in ginseng field. Net photosynthesis (P N ) was compared between Treatment and Non-treatment of LBM in 3 Year Old Ginseng. P N in control plot recorded 2.94 μmol (CO₂) m -2 s -1 at the first day of experiment, which was similar until the last day of experiment. However, The PN in LBM recorded 2.23 μmol (CO₂) m -2 s -1 , which was lower than that in control plot. As time goes by, The PN in LBM was gradually increased up to 3.21 μmol (CO₂) m -2 s -1 and finally, it was similar with that in control plot at 7th day as a 3.20 μmol (CO₂) m -2 s -1 ).