• 한국연초학회지
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• 제7권2호
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• pp.129-139
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• 1985

cent was carried out to study on the effect of temperature and humidity to chemical tobacco leaves during the yellowing stage. The results were follows : In the condition of high humidity and low temperature, yellowing time was delayed ; leaf color appeared lack clearness. In the higher temperature and the lower humidity during the yellowing stage : total sugar, reducing sugar and malic acid content were increased. Decomposition of nitrogenous components elevated in $38^{\circ}C$, 85%RH. Changes of total nitrogen content correlated with total curing time. Adecrease of linolenic acid with a corresponding increase of chlorogenic acid proceeded in the condition of low temperature and high humidity. In a view of tobacco quality by chemical components, the low temperature and high humidity during the yellowing stage decreased quality of tobacco leaves. It is considered to control of the proper condition of temperature and humidity during the yellowing.

• 농업과학연구
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• 제42권4호
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• pp.293-297
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• 2015

This study was conducted to evaluate the influence of feeding leaf positions on the growth, net formation of fruits, and occurrence of leaf yellowing symptoms (LYS) in muskmelon plants. Plants having five or ten more leaves above the fruit-bearing node produced the greater biomass than those of plants having equal or five less leaves above the fruit-bearing node. The number of leaves above the fruit-bearing node also influenced on the occurrence of LYS. The number of plants with LYS decreased as the number of leaves borne on the nodes above the fruit-bearing node increased. The LYS infected ratio of BL-5 treatment were the greatest, while fruit weight of BL+5 treatment were the greatest among all the tested treatments. In addition, the net formation of BL-5 treatment showed the poorest. Results indicated that maintaining the higher number of leaves over the fruit-bearing node might be feasible the practical method for coping physiological damages from yellowing symptoms.

• 한국연초학회지
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• 제21권1호
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• pp.10-16
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• 1999

Leaves harvested were separated with visual characters into 2 classes such as immature and mature leaves. In the curing process, the prolonged yellowing treatment during yellowing stage was automatically controlled at the different stalk position, and condition of curing process after this period was all the same with conventional ones. In case of prolonged yellowing in immature leaves, increase of price per kg reached to 8 % compared with those of conventional ones. In physical properties, filling capacity and shatter index was decreased with the degree of maturity, and it was equal level in filling capacity of immature leaves between curing method, while shatter index was decreased in prolonged yellowing treatment than that of conventional ones. There was no difference in chemical components between immature leaves of prolonged yellowing and conventional ones. As to the prolonged yellowing of immature leaves, there was decreased in citric and malic acid contents of the nonvolatile organic acids, and it was equal level in all higher fatty acids content of leaves cured by prolonged yellowing treatment compared with in that of conventional curing method. The contents of key compounds such as solanone, damascenone, damascone in the essential oil were lower in prolonged yellowing of immature leaves than those of mature leaves cured by conventional ones.

• 한국토양비료학회지
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• 제42권6호
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• pp.409-414
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• 2009

아까시나무는 척박지에서 적응력이 뛰어나 과거 산림녹화와 사방조림 등에 많이 이용된 수종이다. 그러나 2000년 이후 황화현상이 국지적으로 빈번히 발생해 오다가 2006년에는 전국적으로 확산된 바 있다. 따라서 본 연구는 경기도 오산시 3개 지역에서 아까시나무의 황화현상 피해지와 미피해지 내에서 산림토양의 물리화학적 특성을 조사, 분석하여 그 관계성을 파악하고자 수행되었다. 조사지 일대 토양은 사방지토양, 갈색건조산림토양 및 갈색약건산림토양이 주를 이루었다. 피해지의 유효토심(16cm)과 전토심(25cm)은 미피해지(30cm, 56cm)에 비해 현저히 낮게 나타났다. 또한 미피해지에 비해 피해지 토양에서 고상률은 높은 반면 기상률은 낮고, 가비중도 높은 결과를 보여 근계부내 공기와 수분 이동성의 상대적 저하를 반영하였다. 또한 전체 조사지가 산성도가 매우 높은 강산성 토양이지만 피해지의 토양산도는 평균 pH 4.42로 미피해지의 pH 4.54보다 다소 낮았으며, 토양 내 유효인산, 칼슘, 마그네슘 함량과 염기포화율의 결과 역시 피해지에서 낮게 나타났다. 이러한 미피해지에 비해 열악한 황화현상 피해지의 토양 물리화학적 성질은 양분과 수분에 대한 보유 및 공급능력의 상대적 저하로 아까시나무 임분이 다른 환경 스트레스에 보다 민감하게 반응할 수 있음을 반영한다.

• 한국식물병리학회지
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• 제11권3호
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• pp.197-209
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• 1995

This paper is a third report about the new fungal diseases of economic resource plants in Korea. It contains short descriptions on symptoms, occurrence conditions, pathogen, and some phytopathological notes for each of 10 fungal plant diseases. They are angular leaf spot of Achyranthes japonica by Cercospora achyranthis causing leaf spot and defoliation in the shade of plants, leaf spot of Armoracia lapathifolia by Cercospora armoraciae causing leaf spot to blight from the rainy season to autumn, hypophyllous mold of Dioscorea tokoro by Distocercospora pachyderma causing leaf spot and yellowing, hypophyllous mold of Artemisia spp.by Mycovellosiella ferruginea causing leaf spot and yellowing, angular leaf spot of Aralia elata by Pseudocercospora araliae causing velvety leaf spot and defoliation, hypophyllous mold of Lycium chinense by Pseudocercospora chengtuensis causing velvety leaf spot and defoliation from the rainy season to autumn, angular leaf spot of Diospyros lotus by Pseudocercospora disospyri-morrisianae causing leaf spot and defoliation from summer to autumn, brown leaf spot of Impatiens textori by Pseudocercospora nojimae causing leaf spot to blight from the rainy season, leaf spot of Cephalonoplos segetum by Ramularia cirsii causing leaf spot to blight throughout the growing season, and white mold of Leonurus sibiricus by Ramularia leonuri causing leaf spot to blight mostly in autumn.

• 한국연초학회지
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• 제5권2호
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• pp.9-15
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• 1983

The effect of leaf dehydration process and air flow capacity of bulk curing on physical properties and composition of cured leaves was studied, respectively, during flue- curing. Cured leaves from excessive moisture during yellowing stage and those from rapid dehydration Process inevitably during later stages, tend towards lower equilibrium moisture contents, higher shatter index, hither protein nitrogen, and leaf scalding or deterioration of Beaves with redish cast. Early dehydration at the yellowing stage re suited in increasing of p Bamitic, stearic, linoleic, and linolenic acid contents, but showed reduction of brightness difference between upper and lower surface of the cured leaves, Leaf surface lipid decreased with the progress of curing stages, more conspicuously during later stage. Lowering air flow capacity of fan by 50oye during stem drying stage resulted in increasing of leaf surface lipid and 25oye decreasing of electric power consumption , but curing period and kerosene consumption were not affected.

• 한국작물학회지
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• 제36권5호
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• pp.459-480
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• 1991

인삼의 생리장해를 산지중심으로 증상별로 종합검토하였다. 뿌리의 장해는 적피, 은피, 동해, 동해, 근부, 안삼, 출아불재, 달래삼, 소수가 있고 지상부에는 황엽, 조기낙엽, 소엽, 지엽, 백반엽, 동해, 풍해와 경열이 있다. 적피와 황엽이 인삼생산에 가장 크게 영향한다. 농약해, 붕소과 잉해 및 산업공해에 의한 피해 경우도 보고되었다. 원료수삼 가공한 후의 품질요인에 관계되는 생리장해들도 검토하였다.

• Journal of Forest and Environmental Science
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• 제39권1호
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• pp.49-54
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• 2023

For unknown reasons, a few trees in a private chestnut orchard in Icheon si, Gyunggi-do suffered leaf chlorosis and growth decline. Based on symptoms, phytoplasma was a probable cause. Leaf samples were collected from two symptomatic and non-symptomatic trees in the orchard for phytoplasma detection. An amplicon of about 1.2 bp size was obtained from both symptomatic trees by PCR with the universal 16S rDNA primers. Sequences of these amplicons were found to have 99% nucleotide sequence identity to the corresponding genomic region of 16SrIII (X-disease group). More than 100 phytoplasma isolates, such as Candidatus phytoplasma pruni, Milkweed yellows phytoplasma, Goldenrod yellows phytoplasma, Tsuwabuki witches'-broom phytoplasma, Candidatus Phytoplasma trifolii, etc. were involved in the list. Phylogenetic analysis revealed that the sequence obtained in this study closely clustered with Candidatus phytoplasma groups. While one of the amplicons shared 91% identity with the Candidatus phytoplasma castaneae, the other shared only 47%. It needs further analysis and investigation to determine the exact taxonomy. Meanwhile, based on the analysis of the sequences, chlorosis, and small leaves were associated with phytoplasma.

• The Plant Pathology Journal
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• 제23권3호
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• pp.151-154
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• 2007

Phytoplasma was identified from leaf lettuce (Lactuca sativa) cultivated in commercial green-house in Korea. Diseased leaf lettuce revealed proliferation of shoots, and yellowing and shrinking of leaves (lettuce proliferation-K). Polymerase chain reaction (PCR) with universal primer pair P1/P6, and aster yellows (AY) specific primer pair R16F1/R1 amplified 1.5kb and 1.1kb length of DNA fragments, respectively. Nucleotide sequences of 16S rRNA gene were determined (Gen Bank accession no EF489024). Phylogenetic analysis of 16S rDNA showed the closest relationship with AY phytoplasma (GenBank accession no. AY389822 and AY389826), indicating that lettuce proliferation-K is a member of AY. Phytoplasma bodies were detected in phloem sieve tubes of diseased lettuce by transmission electron microscopy. The structures had round or pleomorphic shapes with a diameter of 130-300nm. Phylogenetic analysis of 16S rRNA gene, microscopic observation of phytoplasma bodies and symptomatology indicated that lettuce proliferation-K is caused by phytoplasma in the AY group. This is the first report of phytoplasma disease in lettuce in Korea.

• 한국연초학회지
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• 제19권1호
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• pp.57-63
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• 1997

The composition of leaf surface lipid in Flue-cured tobacco and their changes during curing was investigated. The flue-cured variety, Nicotiana tabacum cv. NC 82 was cultivated at Eumsung experiment station in 1996. The samples of riced leaves with different stalk Position(Lugs, Cutter, Leaf and Tips) and different curing stage at half yellowing(24hr), yellowing(48 hr) , color axing(72 hr), midrib drying(96 hr) and cured(120 hr) were collected for analysis of leaf surface lipid. $\alpha$ - and $\beta$ - 4, 8, 13-Duvatriene-1, 3-diol($\alpha$, $\beta$-DVT) were major components in leaf surface lipid extracted with methylene chloride and sugar ester was detected slightly DVT content was increased with ascending stalk position, but increasing trend of total hydrocarbon was not observed. While DVT was decreased throughout curing of tobacco leaves, hydrocarbon content did not show significant change during curing process. Twenty-two duvane compounds were detected by capillary GC in duvane fraction isolated from leaf surface lipid and of which 11 compounds were identified by GC-MS. These compounds were decreased with curing in all stalk position.