Background : Ginseng root rot caused by soil-borne pathogens, Cylindrocarpon destructans and Fusarium solani, is a major factors of replanting failure in ginseng cultivation. Some of the phenolic compounds detected in the soil of commercially cultivated American ginseng could inhibit the seed germination and seedling growth of American ginseng. Our study is to investigate the causes of replanting failure of ginseng by overhead flooding treatment and soil incorporation of ginseng fine root in soil infected with root rot pathogens. Methods and Results : To make soil occurring continuous cropping injury, 2-year-old ginseng infected with Cylindrocarpon destructans replanted in soil cultivated ginseng for 5 years. Treatment are as follows: 1) control, 2) water of 2ℓ was irrigate infected soil of 20ℓ, 3) ginseng fine root of 20g was mixed with infected soil of 20ℓ. Soil pH was increased, while other inorganic components were significantly reduced by overhead flooding treatment. Soil incorporation of ginseng fine root decreased soil pH, but increased EC, NO3, P2O5 and K, meanwhile, did not affected changes in organic matter, calcium, magnesium, sodium. Irrigation treatment in soil occurring replanted failure promoted distinctly above-ground growth of ginseng, and inhibited the occurrence of root rot because inorganic nutrient like NO3, P2O5 and K were decreased to optimal levels, and the density of soil pathogens could be reduced. Growth of ginseng was not inhibited, while root rot was promoted by soil incorporation of ginseng fine root. Conclusion : Irrigation treatment was effective in promoting the growth of ginseng and inhibited root rot distinctly. Ginseng fine root remaining in the soil after ginseng harvest did not affect the above-ground growth of ginseng, while promoted the occurrence of root rot.

Background: Crop rotation plays an important role in improving soil chemical properties, minimizing the presence of disease pathogens, and assists in neutralizing autotoxic effects associated with allelochemicals. Methods and Results: Five rotation crops of sudan grass, soybean, peanut, sweet potato, and perilla were cultivated for one year with an aim to reduce yield losses caused by repeated cropping of ginseng. In 2-year-old ginseng grown in the same soil as a previous ginseng crop, stem length and leaf area were reduced by 30%, and root weight per plant was reduced by 56%. Crop rotation resulted in a significant decrease in electrical conductivity, NO3, and P2O5 content of the soil, whereas organic matter, Ca, Mg, Fe, Cu, and Zn content remained-unchanged. Soil K content was increased following crop rotation with sudan grass and peanut only. Rotation with all alternate crops increased subsequent ginseng aerial plant biomass, whereas root weight per plant significantly increased following crop rotation with perilla only. A significant positive correlation was observed between root rot ration and soil K content, and a significant negative correlation was observed between ginseng root yield and the abundance of actinomycetes. Crop rotation affected the soil microbial community by increasing gram negative microbes, the ratio of aerobic microbes, and total microbial biomass whereas decreases were observed in actinomycetes and the ration of saturated fatty acids. Conclusions: In soil exhibiting crop failure following replanting, crop rotation for one year promoted both soil microbial activity and subsequent ginseng aerial plant biomass, but did not ameliorate the occurrence of root rot disease.

Background : Cylindrocarpon root rot, caused by Cylindrocarpon destructans and Fusarium solani, is a major disease which lead to replanting failure in ginseng garden. Chlamydospores of C. destructans, generated by poor environmental condition, can survived more than ten years in soil without host plant, ginseng. Density of soil pathogens gradually decreased as the progress of time since ginseng was harvested. Methods and Results : Soil chemical properties was analyzed from soil samples of 43 regions in farmer’s ginseng garden to study the variation of content and the correlation among inorganic contents. Soil samples of 24 regions was also analyzed to study correlation between progressed-year after ginseng harvest and soil chemical properties. Variation of soil chemical properties in descending order was Fe, Zn, P2O4, NO3, Mn. The content of Fe and Zn were great variation among inorganic chemicals of soil of farmer’s field. Electrical conductivity to induce physiological demage in excessive concentration showed highly significant positive correlation with the content of NO3 and K. As the progress of year after ginseng harvest, the content of organic matter and zinc was increased, while pH and Na were decreased in farmer’s field to cultivate ginseng. There were highly significant positive correlation between the progress of year after ginseng harvest and zinc content in farmer’s field to cultivate ginseng. Ratio of root rot of 2-year-old ginseng showed significant positive correlation with K content, and negative correlation in experimental field cultured by six rotation crops for one year. Conclusion : Root rot by soil pathogens was closely related with the content of potassium and zinc in soil chemical properties.

Background : Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replanting failure in ginseng garden. Methods and Results : Solarization was done in the infested soil of the greenhouse for summer season (from July 24 to Autumn 31, 2014) after putting green manure (Sudan grass) and calcium cyanamide (CC) into the soil. Mycelium and conidia of C. destructans died at 4 0℃ after 15 hours, and 45℃ after 5 h, but it did not die at 35℃ after 15 h. Those of C. destructans died after keeping it for 2 hours daily at 40℃ for 9 days, and 45℃ for 8 days, but did not die at 38℃ for 9 days. Maximum soil temperature was 55.4℃ in 5 cm depth, 48.7℃ in 10 cm, 44.7℃ in 15 cm, 42.5℃ in 20 cm, and 31.9℃ in 30 cm by putting green manure into the soil and solarization. Reduction of sudan grass increased electrical conductivity (EC), organic matter, P2O5, K, and Mg, while decreased pH, NO3-N, and Na. Addition of calcium cyanamide and urea gave a negative effect on the growth of ginseng because EC and NO3-N were increased excessively than the optimal range. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. But the root disease that occurred between single treatment of sudan grass and the treatment mixed with calcium cyanamide showed not a significant different. Addition of calcium cyanamide showed the decrease of root weight because leaves were dead early by a excessive increase of EC and NO3-N. Conclusion: Soil disinfection using green manure and solarization in greenhouse was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.

Background: Root diseases caused by Cylindrocarpon destructans and Fusarium solani decrease the yield and quality of ginseng. Cylindrocarpon root rot is a major disease caused by replant failure in ginseng fields. Methods and Results: Solarization of infested greenhouse soil was carried out during the summer season after applying green manure (Sudan grass) and Calcium Cyanamide (CC) on the soil. Mycelium and conidia of C. destructans died at 40℃ after 15 h, but they did not die at 35℃ after 15 h. They also died after keeping the soil at 40℃ for 2 h daily for 9 days, and at 45℃ for 8 days, but they did not die at 38℃ for 9 days. Maximum soil temperature was 55.4℃ at 5 ㎝ depth, 48.7℃ at 10 ㎝, 44.7℃ at 15 ㎝, 42.5℃ at 20 ㎝, and 31.9℃ at 30 ㎝ by incorporating green manure into the soil and using solarization. Solarization using green manure mixed with CC was the most effective in decreasing soil-borne pathogens of 2-year-old ginseng. However, the addition of CC decreased the root weight due to the increase in EC and NO3-N. Conclusions: Soil disinfection using green manure and solarization in a greenhouse environment was effective in inhibiting root rot, however, it did not completely kill the soil-borne pathogens.

Background : Ginseng is mainly grown as a break crop in paddy fields after rice has been cultured for approximately 4 - 5 years, because it reduces the negative effects of continuous rice cropping. However, physiological disorders, such as leaf discoloration, occur in ginseng grown in paddy fields with poor drainage and excessive levels of inorganic components. Methods and Results : This study investigated the effect of ridge height on the growth characteristics and yield of 6 year old Panax ginseng. Ridge height was varied by making 20, 30, and 40 ㎝ high ridges in a pooly drained paddy field. Soil moisture content decreased, while electrical conductivity (EC) as the ridge height increased. The NO3, K, Ca, Mg, and Na levels also rose as ridge height increased, but organic matter and P2O4 levels did not. The leaf discoloration ratio rose as the ridge height increased, and root yield reached a peak when the ridge height was 30 ㎝. Conclusion : A ridge height of 30 ㎝ in poorly drained paddy field improved ginseng growth by reducing leaf discoloration and increasing root survival, owing to more suitable soil moisture and EC levels.

To study the effect of crop rotation on the control of ginseng root rot, growth characteristics and root rot ratioof 2-year-old ginseng was investigated after the crops of 18 species were cultured for one year in soil contaminated by thepathogen of root rot. Fusarium solani and Cylindrocarpon destructans were detected by 53.2% and 37.7%, respectively, frominfected root of 4-year-old ginseng cultivated in soil occurring the injury by continuous cropping. Content of NO3, Na, andP2O5 were distinctly changed, while content of pH, Ca, and Mg were slightly changed when whole plant of crops cultured forone year were buried in the ground. All of EC, NO3, P2O5, and K were distinctly increased in soil cultured sudangrass, pea-nut, soybean, sunnhemp, and pepper. All of EC, NO3, P2O5, and K among inorganic component showed negative effect onthe growth of ginseng when they were excessively applied on soil. The growth of ginseng was promoted in soil cultivatedperilla, sweet potato, sudangrass, and welsh onion, while suppressed in Hwanggi (Astragalus mongholicus), Deodeok(Codonopsis lanceolata) Doraji (Platycodon grandiflorum), Gamcho (Glycyrrhiza uralensis), Soybean. All of chicory, lettuce,radish, sunnhemp, and welsh onion had effective on the inhibition of ginseng root rot, while legume such as soybean,Hwanggi, Gamcho, peanut promoted the incidence of root rot. Though there were no significant correlation, NO3 showedpositive correlation, and Na showed negative correlation with the incidence of root rot.

In this study, the clinical safety and toxicology of oral ingestion of supplement capsules containing ginsengradix was investigated in healthy young volunteers. This study was a pilot randomized, double blinded, placebo controlledtrial. The healthy volunteers were divided into 6 groups of 20 each (10males and 10 females). They took the ginseng powderfor 35 days (3g/day) for safety evaluation. There were measured general healthy levels such as hematological, biochemical andelectrocardiographic parameters. After the first week, besides Korean white ginseng the other treatments led to an significantincrease of white blood cells. Korean red ginseng increased UREA (blood urea nitrogen) in healthy volunteers, but it didn’texceed the range of normal values, and in the subsequent process of treatment there is no effect of elevating UREA. After thethree weeks, Korean white ginseng showed relatively low the content of blood glucose and low-density lipoprotein cholesterol.After the five weeks, compared with the other treatments, Korean red ginseng increased white blood cells, platelet distributionwidth and average volume of platelet. Korean white ginseng decreased low-density lipoprotein cholesterol. American ginsengdecreased blood creatinine in healthy volunteers. In conclusion, through test the blood routine, urine routine, liver function,renal function, blood glucose, blood lipid and electrocardiogram, the healthy volunteers continuous taking ginsengfor 35 days (3g/day) is safe and reliable, and have no obvious adverse reactions and side effects.

Physiological disorders such as symptoms in leaf colored with brown spots are so many occurred in ginseng garden cultivated with paddy soil. This study was carried out to inhibit the symptoms of brown-colored leaf in 3-year-old ginseng by fertilizing calcium hydroxide [Ca(OH)2] of 100 ~ 400 ㎏ per 10a on paddy soil before transplant of seedling. Soil pH was rapidly increased, while Fe was decreased in soil by the increase of application level of calcium hydroxide. Soil pH was increased from 4.53 to 6.18 when calcium hydroxide was fertilized at level of 100kg per 10a. The content of Fe in ginseng leaf was decreased more than the control by fertilizing calcium hydroxide in soil. Ratio of brown-colored leaf and plant height and leaf area were decreased by the increase of calcium hydroxide. Ratio of survived root and yield of root showed the peak at the application level of 100 ㎏ per 10a, and both of them were gradually decreased by the increase of calcium hydroxide. The decrease of missing plant rate above the application level of 200 ㎏ per 10a had a negative effect on the decrease of yield of root.

To control the disease of root rot in ginseng nursery, inorganic sulfur solution of 0.1%, 1.0%, and 2.0% were irrigated by amount of 10ℓ per 3.3m2 before sowing. On the last ten days of July, Fusarium solani and F. oxysporum were similarly detected by 44.8% and 43.8%, respectively, while Cylindrocarpon destructans was low detected by 4.4% in the diseased seedling. The more sulfur's concentration was increased, the more soil pH was decreased. Soil pH was decreased from 5.87 to 4.59 by the irrigation of sulfur solution of 1.0%. The more sulfur's concentration was increased, the more electrical conductivity (EC) of soil was increased. EC was increased from 0.27 dS/m to 1.28 dS/m by the irrigation of sulfur solution of 1.0%. Irrigation of sulfur solution was effective on the inhibition of damping-off caused by Rhizoctonia solani in ginseng seedling. Control value for damping-off by the irrigation of sulfur solution of 1.0% and 2.0% were 75.7%, and 78.5%, respectively. Growth of leaf was inhibited by the irrigation of sulfur solution of 2.0%. Root weight per 3.3m2 showed the peak in sulfur solution of 1.0%, while survived-root ratio and root weight per plant were decreased in the level of 2.0%. Survived-root ratio of seedling in sulfur solution of 1.0% was distinctly increased by 4.7 times compare to the control, but control value for root rot was relatively low as 49.2%. Mycelium growth of C. destructans, F. solani, and R. solani were distinctly inhibited by the increase of sulfur's concentration in vitro culture using PDA medium.

To study the cause of physiological disorder in leaf of ginseng cultivated at paddy soil, the degree of brown-colored symptom (BCS) and the contents of inorganic matter in leaf were investigated by irrigating the solution of ferric andferrous iron of 0.1~2.0%, and citric acid of 1.0~4.0% on bed soil, respectively. Ratio of BCS by variety was as high as85.0% in Yoenpoong, while it was as low as 5.4%, 7.5% in Chunpoong and Hwangsook, respectively. The contents ofinorganic matter of leaf in Yoenpoong were lower in P₂O5, Ca, and Mg, while it were higher in K, Fe, and Mn than othervariety. Iron solution caused BCS more distinctly when each ferric and ferrous iron were dissolved with 1.0% citric acidthan when each iron was dissolved without citric acid. Ferric iron caused BCS more effectively than ferrous iron. BCSoccurred in 4.0% citric acid was as same as 2.0% ferric iron mixed with 1.0% citric acid. Low P₂O5 and high Fe content inleaf appeared in both of artificial and natural symptoms. We concluded that excessive Fe uptake caused BCS to leaf becausethe solubility of iron was increased in condition of low soil pH.