• Korean journal of applied entomology
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• v.26 no.4 s.73
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• pp.267-268
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• 1987

Out of 8 oil cakes used for soil amendment, Margosa, Undi and Karanj cakes were found to reduce the ginger rot. However, maximum increase in yield was found in Karanj cake followed by Roselle and Mustard cakes.

• Mycobiology
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• v.33 no.1
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• pp.7-11
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• 2005

Twenty-two isolates of Sclerotium rolfsii causing spotted leaf rot from Varanasi, India were grown on 6% Cyperus rotundus rhizome meal agar (CRMA) medium for the induction of athelial stage (Athelia rolfsii). Only one isolate obtained from Sphaeranthus indicus formed basidial stage on CRMA medium while the other 21 isolates did not. Basidial stage was also produced in S. indicus isolate at different concentrations (5.5, 6.0 and 6.5% w/v) of CRMA medium. Size of basidia, sterigmata and basidiospores of this isolate was measured. Basidia clavate, hyaline and measured $10{\sim}12{\times}4{\sim}5\;{\mu}m$ in size, basidiospores hyaline, unicellular, subglobose to ellipsoid produced on sterigmata and measured $3{\sim}5{\times}2{\sim}4\;{\mu}m$ in size, sterigmata hyaline and measured $4{\sim}5{\times}1.5{\sim}2\;{\mu}m$ in size. The results of the present study revealed wide variation in spotted leaf rot isolates of S. rolfsii. A reddish zone around the colony of S. rolfsii isolate from Vernonia sp. was observed on CRMA medium. HPLC analysis of the zone revealed the presence of gallic and ferulic acid which were also thought to be responsible for reduced mycelial growth of the isolate on CRMA medium.

• Korean Journal of Plant Resources
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• v.12 no.4
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• pp.289-296
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• 1999

The availability of Bacillus polimyxa 'HB 26-5' as a biological control agent was investigated. The antagonistic bacteria Bacillus polymyxa 'HB 26-5' grew well on the media at pH 7.0 and the optimum growth temperature was $25^{\circ}C$. The pH of the media changed to weak acid(pH 6.1~6.5) at the beginning of incubation, but to weak alkali(pH 7.8~8.2) at 7days after incubation. The best carrier to enhance colonization of the bacteria were the mixture of rice bran and peat, or rice bran and kaoline, in those formulation the density of the bacteria was changed slightly, though the density was beginning to decrease 3 weeks after application at field. In view of the physical characteristics of the formulation for the density maintenance during storage such as the hardness and the size, the best one was the formulation consisted of sodium alginate 2%, kaolin 15% and rice bran 3%.

• The Plant Pathology Journal
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• v.17 no.4
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• pp.227-230
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• 2001

Bioassay techniques using young leaves and roots were developed to screen resistance of Atractylis spp. against Phytophthora drechsleri. Among 638 plants collected from various regions of Korea from 1994 to 1996, 67 were pre-screened in fields naturally infested with P. drechsleri, which is the causal pathogen of rhizome rot of Atractylis. Among the pre-screened sources, 18 (ca. 26.8%) were highly resistant to the pathogen in leaf inoculation. In the root inoculation test, abundant sporangia were formed in susceptible plant roots, while only a few or no sporangia were produced on the roots which were found resistant in the leaf inoculation test. Among the selected resistant plants, A. japonica 96066 and 96104 were used to cross with another species, A. macrocephala 96362 that showed high yield with good quality of rhizome but susceptible to the pathogen. The F$_1$hybrids designated as HA03 turned out to be resistant to the pathogen, indicating that resistant gene(s) was inherited. Among intra-species hybrids of A. japonica, HA07 and HA09 were resistant to the pathogen in leaf inoculation and moderate in root inoculation. However, HA08 was susceptible in both inoculation tests. This result suggests that the parent material might be genetically heterogeneous. Further genetic study should be carried out to verify this phenomenon.

• Korean Journal Plant Pathology
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• v.12 no.3
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• pp.331-335
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• 1996

1993년 전북완주와 충남 서산 지역에서 생강 근경 부패병에 감염된 식물체로부터 Pythium sp.를 분리하였으며, 52균주를 형태적 특징과 병원성 검정을 통해 Pythium zingiberum으로 동정하였다. P. zingiberum으로 동정된 균주들이 재배지에서 사용되는 metalaxyl(MT), metalaxyl+copper oxychloride(MC), echlomezol(EM) 및 propamocarb hydrochloride(PC)등에 균사 생장, 난포자 형성에 미치는 영향 및 약제방제 효과 등을 검토하였다. MT, MC, EM 등이 혼합된 평판배지에서의 균사생육 정도는 50, 100 mg/L에서도 균사생장 억제를 나타냈으나 3균주는 EM 100mg/L에서도 균사생장이 저지되지 않았다. 100mg/L에서도 균사생육 억제효과가 적은 PC의 경우 저항성균주의 난포자 형성량은 약제 희석농도가 높아질수록 저하되었으나, 감수성을 나타낸 균주는 10, 50mg/L에서 오히려 증가하였다. 또한 폿트실험을 통한 약효검정 결과에서도 MT, MC, EM등은 대조구에 비해 생강 근경부패병을 억제하였다.

• Korean Journal of Environmental Agriculture
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• v.19 no.1
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• pp.62-66
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• 2000

This study was conducted to determine the soil chemical properties and microbial flora of platycodon and their effect on rhizome rot incidence. Sampling sites were Keochang 4, Kimhae 7, Haman 6, Chinju 6 and Koseong 3 fields in Kyongnam province and Hongcheong 6 fields in Kangwon province. The root disease incidence rate was in the order of Haman 56.8%, Hongcheon 52.5%, Kimhae 36.7%, Koechang 35.3%, Chinju 32.3%, Koseong 30.0%. The yield at the Chinju 36.17 Mg/ha was higher than that of Koseong 25.00 Mg/ha, Kimhae 13.57 Mg/ha, Koechang 11.75 Mg/ha, Haman 9.50 Mg/ha, Hongcheon 5.24 Mg/ha. The soil K, $NH_4-N$ content and EC value of injury root were higher than those of normal root. The root CaO content was positively correlated with yield $Y=20505X-367.9(R^2=0.129^{\ast})$. The Fe and Zn content of normal root were higher than those of injury root, while the T-N, $P_2O_5$ and $K_2O$ content of normal root were lower than those of injury root. The population of bacteria, actinomycetes and bacteria/fungi ratio increased in soil of normal root, but that of fungi decreased.

• Korean Journal of Medicinal Crop Science
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• v.14 no.2
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• pp.107-112
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• 2006

Two Atractylodes species, A. japonica Koidz. ex Kitam. (AJ) and A. macrocephala Koidz (AM) were used in this study. AJ population had higher amounts of Sesquiterpenoids and stronger tolerance to root rot but less vigor of root growth than AM population. Two populations (AJ and AM) were crossed to make interspecific hybrid population. A total of 98 lines propagated clonally were selected from a cross of AJ and AM, and evaluated for contents of sesquiterpenoids, atractylon (ATLN) and atractylenolide III (AT3) using high performance liquid chromatography (HPLC), and growth characters such as plant height, stem number and root weight. HPLC profiles of the hybrids were compared with those of parent plants, and it demonstrated the production of introgression hybrid by crossing between AJ and AM. Of 98 clonal lines,10 lines were selected by 10% level based on the growth vigor and tolerance to root rot, and AJM2102-51 line showed the heaviest root weight (117.1 g/plant) among them. A total of 98 hybrid lines contained on average $0.16\;{\pm}\;0.10\;mg/g$ of $AT3,\;2.00\;{\pm}\;1.37\;mg/g$ of ATLN, and $2.16\;{\pm}\;1.40\;mg/g$ of total sesquiterpenoids, showing high coefficients of variation (above 65%). Ten lines having high contents of sesquiterpenoids were selected, and AJM2101-15 had the highest amount (9.83 mg/g) of ATLN, and showed 40.8 g/plant of root weight similar to mean value (39.9 g/plant) of hybrid lines. The result showed that the introgression of both characters of vigorous growth from AM and high sesquiterpenoids content from AJ could be possible to make new hybrid lines by crossing between AJ and AM.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.1
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• pp.24-31
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• 2000

This study was conducted to determine the effect of soil physical characteristics on rhizome rot incidence of platycodon. Sampling sites were Keochang 4, Kimhae 7, Haman 6, Chinju 6 and Koseong 3 fields in Kyongnam province and Hongcheon 6 fields in Kangwon province. The root disease incidence rate was correlated with soil depth Y=-0.747X+88.19($R^2=0.394^{***}$), soil hardness Y=4.36X+8.93($R^2=0.201^*$), bulk density Y=104.7X-80.99($R^2=0.295^{**}$), clay content Y=1.24X+14.14($R^2=0.196^*$), porosity Y=-3.11X+215.9($R^2=0.220^*$) and silt content Y=-0.75X+67.85($R^2=0.178^*$). The yield was correlated with soil depth Y=0.263X+0.971($R^2=0.105^*$), clay content Y=-0.688X+32.74($R^2=0.158^*$), porosity Y=1.974X-93.19($R^2=0.231^{**}$) and silt content Y=53.05X-108.65($R^2=0.232^*$), The optimum cultivated land of perennial platycodon was soil depth over 1m, soil hardness under $5kg\;cm^{-2}$, bulk density $1.0Mg\;m^{-3}$, moisture content 13~17%. clay content 5~10%, porosity 58~63%, silt content 38~64% and soil texture of silt loam.

• Korean Journal of Medicinal Crop Science
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• v.27 no.4
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• pp.271-277
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• 2019

Background: Rehmannia glutinosa (Gaertn.) Libosch. ex Steud. has long been used as a traditional medicinal plant in Korea. This study was carried out to investigate the emergence conditions during the seedling periods in R. glutinosa. Methods and Results: The rhizomes of R. glutinosa variety (Jihwang 1) were harvested in the 22, March, 2018. The rhizomes were sown on in 50-cell plug trays. The emergence rates of seedlings at $15^{\circ}C$, $20^{\circ}C$, $25-40^{\circ}C$, and $45^{\circ}C$ treatment seedling were 1.3%, 96%, 100% and 0%, respectively. Rhizome rot was occurred at the temperature of $15^{\circ}C$ and $45^{\circ}C$. The emergence rates of seedlings in high moisture (HM), moderate moisture (MM) and low moisture (LM) treatments at $35^{\circ}C$ were 99.3%, 100%, and 0%, respectively. Drought damage was recorded in plant with the LM treatment. Seedling quality surveys were carried out at 10-days intervals from 10 to 60 days after sowing (DAS). Leaf length and leaf width were increasing until 50 DAS and the number of leaves was increasing until 60 DAS. Root length was increasing until 40 DAS, and then, flowering occurred from 30 to 60 DAS. Lastly, at 40 DAS, leaf aging and root enlargement was observed. Conclusions: We concluded that the emergence of seedlings was possible in the range of 20 to $40^{\circ}C$. Considering drying and rotting damage, we concluded that the moderate level of moisture is most appropriate for seedling emergence. In addition, we concluded that optimal seedling periods are between 30 and 40 DAS.

• Korean Journal of Organic Agriculture
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• v.24 no.3
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• pp.435-451
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• 2016

The objective of the present study was to perform a comparative analysis of the chemical properties of the cultivation site soil and growth characteristics of organically and conventionally cultivated ginseng (Panax ginseng C. A. Meyer). Organically and conventionally cultivated ginseng samples (4-, 5-, and 6-year-old) were collected from 52 fields at 14 locations throughout Korea. The samples were collected over three years from 2013 to 2015, with the collection period between October and November of each year. In order to increase the yield of organically cultivated ginseng, the amount of nutrients was increased to match that of the conventional cultivation system, which highlights the need for proper management in accordance with the standards for chemical properties of soil. Growth duration of organic ginseng was ${\geq}60days$ shorter than that of conventional ginseng and its average yield per 1ha was 60% than that of conventional ginseng. Root weight of organically cultivated ginseng was approximately 54% that of conventionally cultivated ginseng. Rhizome diameter and body shape index of organically cultivated ginseng were lower than those of conventionally cultivated ginseng, indicating that organically cultivated ginseng was thinner and longer than conventionally cultivated ginseng. Root length was greater in 5-year-old conventionally cultivated ginseng with a low percentage of paddy-upland rotation fields. The number of rootlets was lower in 5- and 6-year-old organically cultivated ginseng with a high percentage of direct seeding cultivation. Dry weight was distinctly lower in 5- and 6-year-old organically cultivated ginseng with early defoliation than that of conventionally cultivated ginseng. Incidences of notched belly and root rot tended to be higher in conventional cultivation, with the incidence of notched belly being distinctly higher in 4- and 6-year-old roots and root rot being more prevalent in 5- and 6-year-old roots. Red discoloration and eelworm damage, which are highly affected by soil moisture, were most common in the organically cultivated 4-year-old roots. Organically cultivated ginseng showed early defoliation than conventionally cultivated ginseng, as a result, its yield and weight were low, while the incidence of physiological disorders was low. In order to increase the yield of organically cultivated ginseng, studies on cultivation technology that can overcome early defoliation, as well as soil moisture management that can minimize physiological disorders, are required.