• Research in Plant Disease
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• v.21 no.3
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• pp.215-221
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• 2015

This study was conducted to control ginger rhizome rot treated with the combined treatment, the hairy vetch, carbonized rice husk and eggshell calcium in organic ginger farm. Early symptoms of leaf yellowing and plant wilt began in the chemical fertilizer treatment on July 1. Ginger rhizome rot was more progressed on October 2, and stem browning and dead plant showed a high disease incidence with from 36.7% to 43.0%. On the other hand, the combined treatment did not occur at all until July 1 and delayed the disease incidence to October 2. It showed a low disease incidence of 1.3% to 1.7%. In the combined treatment, the content of soil Na, Fe, Cu was decreased and organic matter was increased twice with 31.6% than previous. Population density of Pythium sp. is lower in the combined treatment ($0.3-2.0{\times}10^3cfu/g$ than the chemical fertilizer treatments ($12.0-12.3{\times}10^3cfu/g$). The combined treatment, hairy vetch, carbonized rice husk and the eggshell calcium is able to control the ginger rhizome rot in organically cultivated ginger field.

• Plant Resources
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• v.6 no.1
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• pp.53-56
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• 2003

To develop optimal storage method of root of Anemarrhena Rhizome, which has been grown as major cultural herbal medicine material, root of Anemarrhena Rhizome was stored for 10 months with different packing materials and sealing methods. The loss in dry weight as influenced by packing materials and sealing methods was the lowest at vacuum packing and followed by complete sealing methods with transparent polyethylene film. The rot ratio of root during the storage period was not significantly different among packing materials but was significantly different among sealing conditions. Conclusively vacuum packing and complete sealing with polyethylene film appears to be optimal for storage of Anemarrhena Rhizome.

• Korean Journal Plant Pathology
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• v.12 no.3
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• pp.336-344
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• 1996

생강뿌리썩음병은 충남 서산, 태안지역이 전북지역보다 3배나 심하게 발생하여 평균 발병주율이 18.1%에 달하였다. 이 병은 서산, 태안지역에서 7월 초순부터 발생하기 시작하여 한여름철의 기온이 높고 비가 많이 오는 장마가 7,8월에 급격히 증가하였으며 기온이 서늘해지기 시작하는 9월 중순까지 진전하였다. 서산, 태안지역과 완주지역은 토양의 이화학적성상 및 미생물상에 큰 차이를 보였으며 완주지역 토성은 서산, 태안에 비해 모래성분이 많고 pH가 낮으며, 유기물, 인산, 치환성 양이온의 함량도 낮았다. 진균, 세균, Pythium spp., Bacillus spp.의 토양내 밀도는 원주지역에서 낮았으나 B/F치는 서산, 태안지역보다 높았다. 완주지역에서 발병이 낮았던 것은 이 지역의 생강이 주로 답전윤환의 작부형태로 논에서 재배되기 때문으로 생각된다. 뿌리썩음병의 발병정도와 재배토양의 이화학적성상과의 상관은 관찰되지 않았다. 이 밖에도 초년재배, 답전윤환, 비가림 재배, 지하점적관수, 사양토 토양, 배수가 양호한 포장, 산간경사지 포장, 종강소독 등은 뿌리썩음병의 발병을 적게 하는 요인들이었다.

• Korean Journal of Medicinal Crop Science
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• v.27 no.6
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• pp.404-411
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• 2019

Background: In September 2017, wilting and rhizome rot symptoms were observed on Atractylodes macrocephala Koidz. in Jecheon-si and Eumseong-gun. This study was carried out to isolate hitherto unidentified pathogenic fungi from A. macrocephala and to test the pathogenicity of isolated fungi against Atractylodes spp. genus such as A. macrocephala, A. japonica, and their interspecific hybrids. Methods and Results: The diseased plants were washed with running tap water, and the boundary between the healthy area and the diseased area was cut while the pathogens were isolated by growing cultures from the diseased areas on Phytophthora semi-selective medium. The internal transcribed spacer (ITS) region of the isolates was used in this study for identification. Test plants were cultivated in the glasshouse at 20℃ - 30℃ for 4 months and then used for pathogenicity test. The pots with plants inoculated with mycelial plugs and zoospores were placed at 25℃ for 48 h in a dew chamber where relative humidity was above 95%, and then moved into the glasshouse at 20℃ - 30℃. The presence or absence of pathogenicity of the strains was determined by evaluating the symptom of plant wilting. The inoculation test was performed in three replicates with a non-treated control. Conclusions: On the basis of results of ITS sequence analysis, the strains isolated from the diseased plants was identified as Phytophthora sansomeana. Biological assay using test plants confirmed the pathogenicity of P. sansomeana against Atractylodes macrocephala. This is the first report of rhizome rot in A. macrocephala caused by P. sansomeana.

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.184-190
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• 1997

Lesion enlargement of ginger rhizome rot was most rapid at 35~40 C, but delayed greatly as temperature decreased. Time needed for a killing a ginger plant, 22~25 cm long, was about 5 days at 35~40 C, but was 15 days at 15 C in a growth chamber test. Higher RH above 90%, higher soil moisture level above 80% of maximum soil moisture capacity, and deeper planting below 4cm enhanced the lesion development on ginger stems and rhizomes. Pythium myriotylum existed in field soil as forms of hyphal portion, hyphal swelling body, or oospore- or zoospore-like bodies, and served as the origin of its colonization. Inocula of P. myriotylum was randomly distributed in soil surface around ginger plants, but its density was decreased as increasing soil depth with the highest density at 0~10 cm soil depth. Population density of P. myriotylum did not vary significantly between the rhizoplane and the rhizosphere soil of a ginger plant, but differed greatly between the disessed and healthy plants with several to several hundreds times higher population in the diseased plants. A positive curvilinear relationship was found between P. myriotylum density and ginger rhizome rot severity.

• Journal of Ginseng Research
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• v.19 no.2
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• pp.175-180
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• 1995

The disease development of root-rot [pathogen:Cylindrocarpon destruction (Zinssm.) Scholten] occurred in 2-year old ginseng (Panax ginseng C.A. Meyer) was investigated in the continuous (the first cultivation: 1978∼1982, 2nd cultivation: 1990∼1993 and abolished in 1993 due to replanting problem) and replanted cultivation (period of cultivation: 1980∼1984). In the continuous cultivation, incidences of root-rot were 0.7% on May 3, 48.6% on May 24, and 95.8% on June 14, respectively. In the replanted cultivation, no symptom was observed on May 3 and disease incidence was generally lower compared with the continuous cultivation. On the aerial part of the ginseng infected by C. desiccates, the end and/or margin of leaves were changed to dark reddish color that appeared for behind the root-rot symptom. In this field, the longitudinal growth of lateral root was more inhibited than in the case of the replanted cultivation by C. destmctans. The inhibition rate of rootlet growth was 37.3% in the continuous cultivation as compared with that of replanted cultivation at June 14. Though lesions of root-rot were formed all over the roots, 61.2% of the lesions was positioned within 6 cm under the rhizome. Key words Panax ginseng, Cylindrocarpon destmtan, root-rot of ginseng, replanting problem of ginseng.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.240-245
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• 1995

In order to find out the effect of temperature and shading on the growth and major disease infection of Eutrema wasabi Matsum., experiments were at growth chamber condition and field. Plant height, petiole and rhizome of wasabi were obvious decreased with increase the temperature, from which the optimum air temperature for the plant growth were estimated to be 17$^{\circ}C$. The light intensity of the treatment with 75% shading net was favorable to the length of main rhizome, rhizome weight and whole plant weight. Infection ratio of black leg and soft rot were increased at high temperature condition, however their infection ratio were decreased with increase the shading condition.

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.152-159
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• 1997

Six pathogenic Pythium isolates obtained from diseased ginger rhizomes were identified as Pythum myriotyrum Drechsler based on various morphological and physiological characteristics. The isolates showed strong virulence on underground parts of buds, crowns, rhizomes, roots and aerial parts of leaves and stems as well. The isolates caused rot of germinated seeds of 10 different crops tested, including cucumber and pepper, and markedly inhibited seedling growth of 3 crops tested, including corn and barley. Maximum, optimum and minimum growth temperatures for P. myriotylum were 39~45$^{\circ}C$, 33~37$^{\circ}C$ and 5~7$^{\circ}C$, respectively. Optimum pH for the growth was 6~7. Mycelial linear growth was most rapid on V-8 juice agar, but aerial mycelia were most abundant on PDA and corn meal agar. Zoosporangial and oogonial formation was greatest on V-8 juice agar. Optimum temperatures for the production of zoosporangia and oogonia were 20~35$^{\circ}C$ and 15$^{\circ}C$, respectively.

• Korean journal of applied entomology
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• v.26 no.4 s.73
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• pp.261-265
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• 1987

Three diffeerent types of symptoms were observed according to the pathogen associated with the rhizomes. The maximum rotting was observed in case when Pythium aphanidermatum was inoculated first followed by Fusarium solani. There was no interaction in case of root knot nematode Meloidogyne incognita and Pythium aphanidermatum. Average per cent germination of the rhizomes were increased significantly in each treatment and maximum in case of Alliette(.25%). The per cent pre & post drenching rotting was minimum in case of Alliette, Burgandy mixture, Dithane-M 45 and Difolatan. These fungicides also increase the yield of rhizome significantly.

• Korean Journal of Medicinal Crop Science
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• v.9 no.3
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• pp.211-219
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• 2001

The disease incidence rates of Phytophthora root rot of A. macrocephala caused by P. drechsleri were dramatically increased in two distinctive periods at experimental fields of National Crop Experiment Station(NCES), Suwon, in 1999 and in 2000 ; one was in the period of 30 to 45 days old seedling stage in spring and the other was just after heavy rainy season in late summer or in early fall. The disease was occurred at seedling stage under the conditions of ${{\geq}15^{\circ}C}$ of average temperature with ${{\geq}100mm}$ rainfalls for 20 days and the tendencies were similar in both year. By the disease, rhizome propagated field was more damaged(18.6%) than seed propagated field(56.0%). Comparing the disease incidence rates at five different fields in Suwon, Youngju and Andong, the damages at soil improving fields and non-mulching fields were less severe than those at continuous cropping fields without soil improvement and mulching fields and occurrence. Expansion of the disease were seemed to be highly related with the populations of P. drechsleri in soils depend on the cultivation method and field conditions. Although the populations of the pathogen in soils collected from Andong and Youngju, in which rhizome were continuously propagated for two and three years respectively, were comparably less than that from Suwon, in which rhizome were propagated for one year, however, the damages by the disease were more severe in Andong and Youngju. So, two or more years of cultivation at the same field may not be useful for Atractylodes plants..