• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.61-67
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• 1984

In an attempt to obtain a basic information to develop methods of an effective chemical control and disease forecasting of panicle blast of rice, effects of conidial number of the causal fungus, Pyricularia oryzae, collected in different periods and the rate of leaf blast occurrence on the occurrence of panicle blast were investigated. Conidial number the fungus collected in 5 days before and after heading date were closely related with panicle blast occurrence. But no relationship was obtained between the occurrence rate of leaf blast and that of panicle blast. Considering the incubation period of the disease, we presume that the most effective application periods of chemicals are 5-10 days and 10-15 days before heading, when immediate effective chemicals and slow effective chemicals are applied, respectively.

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.356-369
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• 1985

In Korea, inevitable researches for the blast control exactly started from 1927 by the organization of Office of Rural Development with the local extensive outbreak of panicle blast at Jeonlla Buk-Do Province in 1926. At present, the rice blast is still one of the most destructive and widespread diseases in spite of considerable contributions by rice scientists, particularly plant pathologists during last 55 years in Korea. Rice blast control and management are very difficult because of the marked variability in pathogenicity of the blast fungus. From the results obtained through the disease surveys during last 70 years, different 3 prevalence type of blast such as bimodal leaf-blast type, bimodal panicle-blast type and bimodal continual blast type were recognized. In generally speaking, pattern of blast outbreak is said to be characterized by severe outbreak of panicle blast after slight outbreak of leaf blast with discontinuity between leaf and panicle blast. So we have to pay much attention for successful management of panicle blast giving direct influence to rice yield. Main factors induce blast epidemic were pointed out to be breakdown of the disease resistance, nutritional unbalance such as excess application of nitrogen, delay of transplantation and longspell of rain fall by extensive surveys and researches on blast during last 70 years in Korea. The fact some of Japonica varieties such as Kokuryomiyako, Tamanishiki, Ginbozu and Pungok belong to varietal group A had been cultivated with extensive acrage over 30 years in this country should be mentioned by Korean rice scientists. Differences in field resistance between varieties in the same group are detectable and apparently small but sometimes epidemiologically significant differential effects may be found out in case of blast. Much more attention should be payed to accumulate the knowledges on field resistance for successful management of blast. Excess application of nitrogen is more effective to outbreak of panicle blast than that of leaf blast of IR varieties. In comparatively low level application of nitrogen infection rate of panicle blast of IR varieties is considerably high. Low temperature effects on outbreak of blast is very great. It results in remarkable increase of the inoculum potential on the leaf lesions and infection of panicle blast in leaf sheathes of IR varieties during the booting stage. In economic point of view, it is concluded that 5 times sprays of effective fungicides including 3 times before and 2 times after heading is good enough to control blast. We have experienced no one of control measures for blast is superior to all others. The integrated control measures was established as guideline of blast control around 1950 in Korea. This guideline must be helpful for rice growers as long as rice growing continue.

• 중국학논총
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• no.43
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• pp.33-54
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• 2014

本文所探討的主題是關於晩明與朝鮮後期小品文的'病'之美學, 病是一个從晚明與朝鲜后期的小品文出現的特殊素材, 是一個表現眞情眞趣韻致的方法論. 晚明與朝鲜后期的小品文作家提唱童心表現眞趣, 也通過病表現眞情. 病是眞性的表露. 有病, 才有個性. 才有鋒芒, 有與世俗不同之處, 不受世俗所汚影響, 沒有世故之態的人格. 病之所以爲明季世人與18世紀朝鮮後期所稱訟以爲美, 乃在於其怪與奇. 病的主要原因是癖狂懶痴傲.. 本稿分析以癖爲主. 下列小品文的'癖之美學的特徵. 其一. 癖是一種特殊幷几近变态的行为. 但在晚明文人與朝鲜小品文人的眼里, 病可是真情至性的表現. 其二. 晩明與朝鮮文人以爲生活是有寄託的, 有寄託才能安心度日. 其三. 晩明與朝鮮小品作家通過癖, 不但能使生活和心情獲得寄託, 也可以轉移心思, 移情養性. 其四, 癖是可以有治兵養心. 通過以上的共通審美意識, 講道結論, 晩明與朝鮮後期小品文有密切的关系. 再說朝鮮後期小品文受到晩明小品文的影響.

• Korean Journal of Agricultural Science
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• v.18 no.2
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• pp.93-98
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• 1991

This research was undertaken to clarify derivation of resistance of Japonica type of rice varieties to rice strip virus. 1. The source of resistance to the rice strip virus in rice cultivars of Nagdongbyeo, Hwaseongbyeo, Gwangmyeongbyeo, Yeongdeogbyeo, Dongjinbyeo, Gyehwabyeo, Hwacheongbyeo, Suweon 362, Iri 390, Milyang 64, Milyang 96 and Milyang 101 was derived from rice cultivar of Modan. 2. The resistance of rice cultivars Donghaebyeo, Sinseonchalbyeo, Palgongbyeo, Hwajinbyeo and Somjinbyeo to the rice strip virus was derived from cultivar Milyang 23 and/or Nangdongbyeo. 3. The resistance of cultivars Jinjubyeo, Tamjinbyeo and Yongsanbyeo to the rice strip virus was derived from cultivar HR 769 and/or Milyang 20. 4. The resistance of cultivar Daecheongbyeo to the rice strip virus was deriverl from cultivar Nagdongbyeo and/or HR 769.

• The Korean Journal of Mycology
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• v.9 no.4
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• pp.169-176
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• 1981

Survey of sesame crop in the cultivators' field in the district of Daejeon, Yuseong, Sintanjin, Nonsan and Keumsan revealed that Alternaria and Corynespora blights of sesame were wide spread and caused severe damage to sesame plants. Symptoms of a new disease of sesame in Korea caused by Alternaria sesami were spreading, dark-brown to black, water-soaked lesions which often could be traced the entire length of the stem. In severe infections, several lesions coalesced together involving a major portion of the blade and the infected leaves dried and usually dropped off. Symptoms of Corynespora blight, caused by Corynespora cassiicola, were irregular shaped, concentrically-zoned, light brown to reddish brown lesions which later coalesced and caused defoliation. Stem lesions were long, reddish brown streaks that often coalesced, blighting the plants. The optimum temperatures for mycelial growth of A. sesami and C. cassiicola were about $27^{\circ}C$ and sporulations of these 2 fungi were stimulated under alternating light and darkness. Mycelial growth and sporulation of A. sesami and C. cassiicola were the greatest on sesame oatmeal agar (SOA) and potato dextrose agar (PDA), respectively.

• Korean Journal of Veterinary Research
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• v.9 no.1
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• pp.23-62
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• 1969

Throughout the studies the following experimental results were obtained and are summarized: 1. Multiplication of agents in primary cell cultures of both GF classical and CR-64 acute strain of Marek's disease infected chicken kidneys was accompanied by the formation of distinct transformed cell foci. This characteristic nature of cell transformation was passaged regularly by addition of dispersed cell from infected cultures to normal chicken kidney cell cultures, and also transferred was the nature of cell transformation to normal chick-embryo liver and neuroglial cell cultures. No cytopathic changes were noticed in inoculated chick-embryo fibroblast cultures. 2. The same cytopathic effects were noticed in normal kidney cell monolayers after the inoculation of whole blood and huffy coat cells derived from both forms of Marek's disease infected chickens. In these cases, however, the number of transformed cell foci appearing was far less than that of uninoculated monolayers prepared directly from the kidneys of Marek's disease infected chickens. 3. The change in cell culture IS regarded as a specific cell transformation focus induced by an oncogenic virus rather than it plaque in slowly progressing cytopathic effect by non-oncogenic viruses, and it is quite similar to RSV focus in chick-embryo fibroblasts in many respects. 4. The infective agent (cell transformable) were extremely cell-associated and could not be separated in an infective state from cells under the experimental conditions. 5. The focus assay of these agents was valid as shown by the high degree of linear correlation (r=0.97 and 0.99) between the relative infected cell concentration (in inoculum) and the transformed cell foci counted. 6. No differences were observed between the GF classical strain and the CR-64 acute strain of Marek's disease as far as cell culture behavior. 7. Characterization of the isolates by physical and chemical treatments, development of internuclear inclusions in Infected cells, and nucleic acid typing by differential stainings and cytochemical treatments indicated that the natures of these cell transformation agents closely resemble to those described fer the group B herpes viruses. 8. Susceptible chicks inoculated with infected kidney tissue culture cells developed specific lesions of Marek's disease, and in a case of prolonged observation after inoculation (5 weeks) the birds developed clinical symptoms and gross lesions of Marek's disease. Kidney cell cultures prepared from those inoculated birds and sacrificed showed a superior recovery of cell transformation property by formation of distinct foci. 9. Electron microscopic study of infected kidney culture cells (GF agent) by negative staining technique revealed virus particles furnishing the properties of herpes viruses. The particle was measured about $100m{\mu}$ and, so far, no herpes virus envelop has been seen from these preparations. 10. No relationship of both isolates to avian leukosis/sarcoma group viruses and PPLO was observed.

• Korean Journal of Agricultural Science
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• v.15 no.1
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• pp.23-26
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• 1988

A severe blight disease of lily (Lilium spp.) caused by Botrytis elliptica was found in a vinyl house in Taejon for the first time in 1987. Initial symptom of the disease was brown spotting on leaves and stems of the plants. The spots gradually increased in size and coalesced to form bigger spots and blights on the leaves. Plants with severe damage became brown and sometimes died. In the inoculation experiments, the fungus was found to be pathogenic only to lily, but not to pepper, tomato, ginseng, onion and welth onion.

• Korean Journal of Veterinary Research
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• v.8 no.1
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• pp.6-10
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• 1968

순화(純化)된 뉴켓슬병(病) 바이러스를 얻기 위(爲)한 기초적(基礎的)인 실험(實驗)으로 바이러스 재료(材料)를 완형액(緩衡液)의 종류(種類) 및 수소(水素)이온 농도(濃度), 한천농도(寒天濃度)를 달리한 한천(寒天)겔칼럼에 통과(通過)시켰다. 그러고 바이러스 재료(材料)의 혈구응집력가(血球凝集力價)와 총질소량(總窒素量)을 비교(比較) 측정(測定)하여 다음과 같은 결과(結果)를 얻었다. 1. 한천(寒天)겔 응과법(凝過法)을 뉴켓슬병(病) 바이러스의 순화(純化)에 간단(簡單)히 이용(利用) 할수 있다. 2. pH 7.0 이상(以上)의 인산식염(燐酸食鹽) 완형액(緩衡液)과 5~8%의 한천농도(寒天濃度) 입자(粒子)를 이용(使用)할때 가장 좋은 결과(結果)를 얻을 수 있었다. 3. 매시(每時) 5~10ml의 유출속도(流出速度)일때 55ml 부터 80ml의 유출액중(流出液中)에서 고농도(高濃度)의 바이러스를 얻을 수 있었다.

• Journal of Korean Society of Forest Science
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• v.48 no.1
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• pp.29-39
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• 1980

This study was initiated to find out the possible insect vector and other means of transmission of jujube witches'-broom disease. 1. Eight species of leafhoppers were found to feed on both healthy and diseased jujube trees. Among these, rhombic marked leafhoppers (Hishimonus sellatus Uhler) were most abundant throughout the growing season of jujube trees in all localities surveyed. H. sellatus was far more abundant on diseased trees than healthy ones. 2. Jujube witches'-broom mycoplasma(JWM) was transmitted to jujube seedlings by Hishimonus sellatus. Jujube seedlings inoculated with H. sellatus which had been fed for 14-21 days on diseased jujube plants, developed smaller, chlorotic leaves 40-60 days after inoculation. Electron microscopy of midveins and petioles of the infected jujube seedlings revealed the presence of numerous mycoplasmalike organisms in phloem tissues. 3. Jujube witches'-broom mycoplasma was also transmitted to Vinca rosea plants by H. sellatus. Infected Vinca rosea plants developed vein clearing and marginal chlorosis of upper leaves 25-38 days after inoculation and followed by stunting and ultimate wilting and death of plant. Electron microscopy of petioles and midveins of infected Vinca rosea plant revealed the presence of numerous mycoplasmalike organisms in phloem tissues. 4. H. sellatus survived more than 30 days on jujube, Vinca rosea, carrot, celery, eggplant, hop, Calystegia japonica, Humulus japonicus, Astragalus sinicus, white clover, red clover, and radino clover. Many second generation nymphs of H. sellatus were also abserved on these plants but clovers. 5. Jujube seeds collected from witches'-broom diseased jujube trees yielded healthy seedlings.

• 인삼약초
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• v.4 no.1 s.11
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• pp.48-49
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• 2006