• 한국토양비료학회지
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• 제15권3호
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• pp.156-161
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• 1982

인삼산지포장(人蔘産地圃場)에서 토양유기물함량(土壤有機物含量)은 토양수분(土壤水分)과 근수량(根收量)과 유의정상관을 보였다. 토양수분(土壤水分)은 근수량(根收量), 경직경, 경장, 유의정상관을, 지상부(地上部) 상대 결주율(缺株率), 낙엽율(落葉率), 반점병리병율(斑点病罹病率)과는 유의부상관을 보였다. 현(現) 재배법으로 칸당 2kg 이상(以上)의 수량(收量)을 내려면 토양수분(土壤水分)이 17% 이상(以上) 유기물(有機物)은 2%이상 이어야 할 것으로 나타났고 이에 미달(未達)인 포장(圃場)이 58% 였으며 이들은 대부분(大部分) 사양토(砂壤土)와 양토(壤土)였다.

• The Plant Pathology Journal
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• 제17권3호
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• pp.154-158
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• 2001

A severe root rot of kiwifruit caused by a species of Phytophthora occurred in 1-to 5-year-old vines at the south coast region of Korea in 1997. Infected vines exhibited leaf chlorosis, scorch and defoliation, root and stem rot, and eventual death. The disease was relatively severe in poorly drained lowlands, of which 19 out of 23 fields were damaged by the disease. Meanwhile, only one among 58 upland fields was infected by the disease. Incidence of infected vines reached over 80% in heavily damaged fields and a species of Phytophthora was isolated from inner tissues of roots, stems, and rhizosphere soils of the plants. The causal pathogen was identified as P. drechsleri based on its mycological characteristics. Pathogenicity of the fungus was confirmed by artificial inoculation to seedlings of kiwifruit 'Hayward'. The pathogen was re-isolated from the inoculated plants showing symptoms similar to those observed in the fields. Root rot of kiwifruit caused by P. drechsleri has not been reported previously in Korea.

• The Plant Pathology Journal
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• 제18권5호
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• pp.271-278
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• 2002

The effect of five plant population densities [5 (D$_1$), 10 (D$_2$), 20 (D$_3$), 30 (D$_4$), and 40 (D$_{5}$) plants/m$^2$] of four groundnut cultivars [ICGV 86699, ICG (FDRS) 10, ICGS 11 and TMV 2] and fungicide application (Kavach, chlorothalonil) to manage late leaf spot (LLS) and rust were studied in a field experiment during the 1995 and 1996 rainy seasons. LLS and rust severities were low in fungicide sprayed plots in all the cultivars irrespective of plant densities. Severities of LLS and rust, and percentage defoliation caused by LLS were significantly more in higher plant densities (D$_4$, D$_{5}$) than in lower plant densities (D$_1$, D$_2$, D$_3$) in fungicide sprayed and unsprayed plots in all the cultivars. All the cultivars gave significantly higher haulm and pod yields in fungicide sprayed plots than in unsprayed plots. Haulm and pod yields were significantly higher in higher plant densities than in lower plant densities. A combination of higher plant densities (D$_4$, D$_{5}$) and fungicide protection against LLS and rust gave maximum yield.yield.

• 농업과학연구
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• 제44권3호
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• pp.348-358
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• 2017

The green peach aphid, Myzus persicae, is one of the most serious insect pest and a vector for a multitude of viral diseases to many crops, vegetables, ornamentals, and fruit trees in the world. A large number of aphids can reduce plant vigor and cause defoliation. Many insecticides have been developed and applied to control the green peach aphid. However, this aphid has displayed a remarkable ability to establish resistance to almost every insecticide. We treated 5 different insecticides registered for M. persicae on pepper leaves and investigated the effects of the insecticides by measuring the time it took to achieve 90% control of the aphids. Acetamiprid worked faster than any other insecticides while cyantraniliprole showed the slowest insecticidal effect. Pymetrozine, pyrifluquinazon, and spirotetramet provided 90% control within similar time. Iwol population's control value was higher than any other populations 24 hours after treatment. When five different unregistered insecticides for M. persicae were treated on pepper leaves, no insecticidal effect was found for gamma-cyhalothrin and novaluron and spinosad showed an insecticidal effect of up to 70% in Iwol population only. Although chlorfenapyr and dinotefuran were not registered for M. persicae, their insecticidal effects were found to be 90% or higher.

• 한국초지조사료학회지
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• 제15권2호
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• pp.124-131
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• 1995

In order to find out optimum seed production date according to different defoliation and flooding period of Italian ryegrass, this studies with Tetrone were canied out on the experimental field of Honam Crop Experiment Station from 1986 to 1988. Treatments included cutting date of Nov. 20 and Apr. 10 and flooding period of 5-25 days. In soil after experiment, organic matter, phosphate and silicate content increased, but potassium content decreased 0.16% than that before experiment. Heading and maturing date of Nov. 20 cutting were same with those of non cutting, those of Apr. 10 cutting lates 6 days to heading date and 2 days to maturing date. Plant height and culm length of Nov. 20 cutting were sirniller to those of non cutting, those of Apr. 10 cutting were shorter and panicle length have no difference between non cutting and cutting. Lodging of cutting treatment was reduced than that of non cutting. Lodgin was increased as flooding period was long, also loding of all treatment occured at 30 days after heading. Two cutting times of Nov. 20 and Apr. 10 have the most fresh yield, while non cutting have the most dry matter yield. Optimun seed productin date was considered to suitable when 35 days after heading (Jun. 14), at this time, seed production was 1,640 to 2,640 kg/ha. Also if flooding j u r y have, seed production was good between 10 days and 15 days after flooding.

• 식물병연구
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• 제24권4호
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• pp.339-341
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• 2018

Amaranth has the potential for good materials related to nutrients and health benefits. There are several diseases of amaranth such as leaf blight, damping-off, and root rot. As a causal agent of soft rot disease, Pectobacterium spp. could infect various plant species. In this study, we isolated the bacterial pathogen causing soft rot of amaranth in South Korea. In Gangneung, Gangwon province during 2017, amaranth plants showed typical soft rot symptoms such as wilting, defoliation and odd smell. To isolate pathogen, the macerated tissues of contaminated amaranth were spread onto LB agar plates and purified by a single colony subculture. One ml bacterial suspension of a representative isolate was injected to the stem of five seedlings of 2-week-old amaranth with a needle. Ten mM magnesium sulfate solution was used as a negative control. 16S rDNA gene and recA gene were sequenced and compared with the reference sequences using the BLAST. In the phylogenetic tree based on 16S rDNA gene and recA gene, GSA1 strain was grouped in Pcb.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 춘계학술대회 및 임시총회
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• pp.37-37
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• 2014

Glomerella leaf spot pathogens can infect apple leaves, causing extensive necrosis and premature defoliation, as well as necrotic spots on fruit. In recent years, the disease has been reported with increasing frequency in China, and appears to be spreading rapidly in some apple-producing areas. In this study, fungal isolates from diseased apples leaves collected in Henan and Shaanxi provinces were analyzed based on morphology, cultural characters, pathogenicity and molecular phylogenetics. It was found that Glomerella leaf spot of apple was caused by two pathogens, Colletotrichum fructicola and C. aenigma. Pathogenicity tests showed that C. fructicola and C. aenigma could infect apple leaves of cultivar Golden Delicious, as well as Gala, Qinguan, Pink Lady, Pacific Rose, Golden Century and Honeycrisp, all of which include Golden Delicious in their parentage. In wound inoculation experiments, C. fructicola and C. aenigma were pathogenic to fruit of Gala, Qinguan, Golden Delicious, Pacific Rose, Starkrimson and Fuji. With non-wounded fruit, C. fructicola was pathogenic to Gala and Golden Delicious, and C. aenigma was pathogenic to Gala. It is concluded that the two pathogens could be differentiated according to pathogenicity to leaves and fruits of different apple cultivars.

• 식물병연구
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• 제10권4호
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• pp.279-284
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• 2004

경상남도 진주와 하동지역의 산초나무 재배단지에서 잎녹병에 의한 피해가 매년 지속적으로 발생하고 있다. 산초나무 잎에 형성된 여름포자세대의 녹포자세대 기주를 밝히고 녹병균을 동정하기 위하여 본 병해의 발생지 주변 곰솔에서 채집된 녹포자를 산초나무에 인공접종하였다. 그 결과 산초나무에서 성공적으로 여름포자가 형성되어 이 녹병균은 녹포자세대를 곰솔에서, 여름포자 및 겨울포자세대를 산초나무에서 형성하는 장세대형 생활사를 갖는 C. xanthoxyli로 동정하였다. 대부분의 형태적 형질은 기존 기록과 일치하였으나 녹포자와 여름포자의 표면돌기 수에는 차이가 있었다. 곰솔과 산초나무에서 채집된 C. xanthoxyli의 건조표본을 이용하여 녹포자세대 및 여름포자세대의 형태학적 특징을 기술하였다. 경남 진주와 하동지역에서 조사된 산초나무에서의 최초 병발생시기는 6월 하순${\sim}$7월 초순이었으며 8월 중의 이병엽율은 17.8%${\sim}$58.7%이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제8권2호
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• pp.139-143
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• 1995

Two hundred eighty weaned Targhee lambs were grazed on annual grass-subclover pastures for 84 d under continuous and rotational defoliation grazing system. At the end of the grazing season, twenty lambs weighing 44 kg were slaughtered directly off the pasture, whereas two groups of 20 lambs each were fed either a alfalfa pellet or a 50% alfalfa/50 concentrate pellet for additional 6 wk until they reached an average live weight of 50 kg. Carcass traits and loin chop palatability were compared. Lambs slaughtered directly off the pasture were lighter than desirable market weight and some lambs had less than adequate fat cover and approximately half of them were graded U.S. Good in quality. Overall conformation and leg muscling was inferior and loin chops were less tender, less juicy and less flavorful. The lambs on alfalfa pellets for 6 wk appeared to be ideal in terms of carcass quality (all Choice except one), fat cover and yield grade. They had better taste panel scores in all palatability traits than off-the-pasture lambs, and most loin chops were acceptable. The lambs on a 50% concentrate diet for 6 wk had a higher conformation score and a greater muscling in the legs. Loin chops had more marbling and better palatability than other groups. However, some lambs had an excessive fat cover and lower yield of retail cuts. It was concluded that additional feeding for 6 wk on alfalfa pellets until the live weight reached 50 kg(for Targhee lambs) was the best way of finishing lambs at the end of grazing season in the California rangeland.

• 한국식물병리학회지
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• 제13권1호
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• pp.22-29
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• 1997

Etiological and ecopathological studi88888es on the leaf blight of kiwifruit (Chinese gooseberry), a disease newly found in 1993 in Korea, were carried out in this experiment. The leaf blight symptom was prevalent in the southern area of Chonnam Province where kiwifruits were widely cultivated. The disease occurred from July to fall, causing early defoliation of kiwifruit vines. Small brownish circular or irregular lesions appeared initially on the leaves, starting from the marginal leaf areas, and enlarged. Afterwards small grayish black granules (acervuli) were formed on the lesions. The color of old lesions changed to grayish brown or grayish white. The causal fungus was identified as Pestalotiopsis menezesiana (Bress. & Torr.) Bissett according to its morphological characters and pathogenicity (pathogenic to Chinese gooseberry and grapevine, but not to other hosts of Pestalotiopsis spp.such as tea, apple, persimmon, and chestnut). As P. longiseta and P. neglecta were reported recently in Japan as pathogens causing similar blight symptoms in kiwifruit, P. menezesiana is a new leaf blight pathogen in kiwifruit. Development of the disease was stimulated by wounding, prevailing wind, and drought. The causal fungus was proven to be overwintered in the diseased leaves on the ground surface.