Background : Ginseng is a perennial, and damage occurs due to various diseases and pests. As a result, yield decreases and quality deteriorates. In particular, it is impossible to be repeatedly cultivated due to root rot, soil-borne disease. For this, in order to control root rot and repeatedly cultivate ginseng by using soil fumigation from virgin soil, this experiment was conducted. Methods and Results : This experiment was performed in ginseng farm field, Geumsan-gun, Chungnam province. And total area was 3ha. And the experiment was conducted in soil where apple trees had been grown. Apple trees were rooted up in 2006. And soil was fumigated in May 2007. With regard to soil fumigant, soil was treated with Basamid of 40kg/10a. After soil fumigation, 5 ton/10a of cattle manure fermented for 1 year was put in the soil in June, and then the soil was cared for by being plowed and rotary-tilled as occasion. Ginseng seeds were sowed in the soil cared for in October 2007. And 4-year-old ginseng was harvested in 2011. The soil from which ginseng was harvested was fumigated by the same method in May 2012, and then ginseng seeds were sowed in 1.5ha in October 2012 and in 1.5ha in October 2013. In October 2013, 3-year-old and 4-year-old ginseng was harvested. And ginseng growth characteristics and root rot incidence was examined. It was shown that 4-year-old ginseng yield after the fumigation of virgin soil was nearly 2 times as high as that of conventional virgin soil cultivation. And root rot didn't occur. After that time, the soil was fumigated again. And when ginseng was cultivated, 3-year-old and 4-year-old ginseng yield was 650kg and 960kg per 10a. And it was shown that root rot incidence was 1.3% and 15.3% in 3-year-old and 4-year-old ginseng respectively. Conclusion : This study showed the results where ginseng can be cultivated repeatedly if soil was fumigated again after ginseng was harvested following the soil fumigation from virgin soil so as to control the ginseng root rot and cultivate ginseng repeatedly.

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: 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.

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.

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.

This study was carried out to investigate the characteristics of Rhizome rot incidence of Platycodon grandiflorus by cultivation period and ridge width and furrow depth. The three types of ridge width 0.8, 1.0, and 1.2 m and several levels of furrow depth and 6 levels cultivation period. This experiment was done in farmer's farm and the treatments were also classified in the same spot. In this investigation, ridge width, soil water content, soil hardness, and cultivation period were positively related with Rhizome rot incidence, however, furrow depth was negatively related with that. So this experiment could draw a conclusion : excess water damage and soil hardness could directly or indirectly effect on the Rhizome rot incidence, so cultivation method should be developed such as making underground ditch or cultivation in well draining soil for escaping excess waster damage.

인삼 연작장해 원인과 경감대책을 수립하고자 2004년에는 2005년까지 작물과학원 증평시험지 연작토양에서 인삼 수확경 과년수와 예정지관리 유무에 따른 시험을 수행한 결과를 요약하면 다음과 같다. 인삼 연작지 수확경과년수가 짧을수록 생존율이 낮아지며 3~4년 경과구 81~95%의 뿌리썩음 이병주율을 보였다. 예정지 관리구는 미관리구보다 생존율이 다소 높으며 뿌리 썩음병 피해도 예정지 미관리와 같은 경향으로 예정지 관리효과는 크지 않다. 수확경과년수가 10년이상의 연작지에서도 연작장해를 일으키는 병원균 (C. destructans)이 분리되므로 재작 또는 연작시는 이점을 고려하여 재배지를 재선정하거나 예정지 토양관리대책을 수립해야 할 것으로 판단된다.