• 한국유기농업학회지
• /
• 제18권1호
• /
• pp.83-92
• /
• 2010

미나리 유기재배 방법을 설정하기 위해 관행 재배구를 대조구로 하고 유용미생물제(effective microorganism), 액상규산염(silicate solution), 및 유기액상비료(organic liquid fertilizer)를 사용하여 재배하였다. 미나리 수확기에 조사한 토양 pH, EC, OM, 유효인산, 치환성 칼슘, 유효규산함량은 수확기에 감소하였고, 치환성칼륨과 마그네슘은 1, 2년차에는 수확기에 감소하였지만, 3년차에는 증가하였다. 대조구에 비해 액상규산염을 사용할 경우 pH, 유기물, 유효인산함량이 감소하였고, 유용미생물제는 치환성 Ca과 Mg, 유기액상비료는 EC와 치환성 Ca과 K가 감소하였다. 미나리에 함유되어 있는 다량원소 가운데 C, N, P, K, 및 S는 대조구보다 함유량이 많았고, Ca과 Mg은 대조구와 비슷하였다. 담배거세미나방과 역병은 모든 처리구에서 비슷한 수준으로 나타났고, 점무늬병은 대조구에서 나타났다. 생육시기별로 처리간에 엽록소 함량 차이는 없었지만, 액상규산염을 사용한 구의 초장은 60.2 cm, 수량 3,698 kg/10a로 가장 적었고, 유기액상비료를 사용한 경우 66.0 cm와 4,387 kg/10a로 가장 많았다.

• 한국식물병리학회지
• /
• 제14권5호
• /
• pp.402-407
• /
• 1998

Phytophthora rot on jujube fruit has occurred at several cultivation areas in Kyung-buk and Kyung-nam provinces. Symptoms consisted of brownish to reddish rot on fruits resulting in early drop or mummification. The causal fungus isolated from infected fruits and adjacent leaf stalks was identified as Phytophthora citricola, which has never been reported in Korea. Sporangia were semi-papillate, noncaducous and highly variable in shapes. Plerotic oospores with paragynous antheridia were abundant is single cultures. Sporangia of two isolates were measured as 38-76$\times$20-40 ${\mu}{\textrm}{m}$ and averaged 51.4$\times$27.0 and 55.6$\times$36.0 ${\mu}{\textrm}{m}$. Oogonia were ranged from 26 to 36 ${\mu}{\textrm}{m}$ and averaged 31.3 and 32.0 ${\mu}{\textrm}{m}$. Colony pattern was slightly radiated with sparse aerial mycelia on common media. Minium, optimum and maximum temperatures for mycelial growth were recorded at 7, 25, and 32$^{\circ}C$, respectively. Among tested media, 10% V8A was the best and $25^{\circ}C$ was better than 15$^{\circ}C$ for oospore formation of the fungus. The jujube isolates of P. citricola were readily differentiated from other closely related species in the genus, namely; P. nicotianae, P. citrophthora, P. cactorum, P. capsici, and P. plalmivora on the basis of PCR-RFLP of r-DNA. The fungus showed strong pathogenicty to jujube, apple, pear, orange, persimmon and eggplant, and relatively weak to citron, tomato, pepper and cucumber. In this study, P. citrocola is firstly identified and jujube fruit rot caused by the fungus is recorded as a new disease in Korea.

• 한국식물병리학회지
• /
• 제14권5호
• /
• pp.445-451
• /
• 1998

A severe Phytophthora rot of strawberry caused by a species of Phytophthora has been widely occurred at major cultivation areas of Kimhae on August in 1997. Incidence of the disease was obtained in the range of 69.2~83.6% in surveyed 4 fields and showed an average of 75.2%. A species of Phytophthora was mostly isolated from the crown of infected strawberry plants and all the isolates were identified as P. nicotianae var. nicotianae (=P. parasitica). The fungus showed strong pathogenicity on strawberry by inoculation test. As a result of the leaf inoculation using mycelial disks of the fungus, both leaves and petioles were darkly browned, and were finally blighted. As a result of the root inoculation of zoospore suspension, both roots and crowns were rotten with dark brown. Although the fungus produced sporangia either on V-8 juice agar medium or liquid medium, the sporangia observed on the liquid medium appeared to be broadly turbinate and noncaducous. Moreover the fungus cultured on the liquid medium often produced sporangia having two papilla. The number of zoospores in sporangia was found to be ranged from 3 or 4 to as many as 20 or 25. In addition, the released zoospore from the sporangium became the cystospore during the prolonged culture of the fungus. The sporangia were measured as av. 49$\times$35 ${\mu}{\textrm}{m}$ with l/b ratio of 1.43. All isolates from crowns were heterothallic and A1 mating type since oospores were abundantly formed on clarified V-8 juice agar by dual culture with P. capsici A2 mating type. Aplerotic oospores were sized 24-26 ${\mu}{\textrm}{m}$. Antheridia were always amphigynous and recoreded an average of 12$\times$10 ${\mu}{\textrm}{m}$. Hyphal swlling were easily observed, and terminal or intercalary chlamydospores were abundantly formed on V-8 juice agar as well as in C/Z solution and sized av. 28.2 ${\mu}{\textrm}{m}$. This is the first report of Phytophthora rot of strawberry in Korea.

• 한국식물병리학회지
• /
• 제14권6호
• /
• pp.646-650
• /
• 1998

Mycological characteristics of Phytophthora nicotianae var. nicotianae SPC10 (A1 type) causing Phytophthora rot of strawberry and the resistances of 11 strawberry cultivars against the pathogen were examined. Optimum temperature for the mycelial growth of the pathogen was obtained in the range of 30~35$^{\circ}C$, and the growth was completely stopped under 13$^{\circ}C$ or over 42$^{\circ}C$. Aerial mycelia were abundant on oatmeal agar (OMA), V-8 juice agar (V8A) and lima bean agar (LBA) medium, although there were slight differences, however, on cornmeal agar (CMA) medium, it was a shape of stellate without aerial mycelia. The colony shape on potato dextrose agar (PDA) medium was rough and irregular whereas the mycelial growth was slow, and some aerial mycelia were only produced in the middle of PDA medium. Optimum temperature for sporangial formation was 3$0^{\circ}C$, and zoospores were mostly released at $25^{\circ}C$ from the sporangia. Sporangia were more produced in C/Z solution with pH 5. 0~6.$0^{\circ}C$ than sterilized distilled water (DSW) and distilled water (DW), and zoospores were also released much more than other solutions. Eleven strawberry cultivars such as Reiko, Hokowase, Eyeberry, Akaneko, Sistakara, Toyonoka, Nyoho, Sulhong, Suhong, Myhong and Wonkyo #3104 revealed the disease incidence up to 88.9~100% by the leaf inoculation with mycelial disk. However, Nyoho and Suhong showed higher level of resistance against the pathogen by root inoculation.

• 한국식물병리학회지
• /
• 제14권5호
• /
• pp.452-457
• /
• 1998

Thirty-eight isolates of Phytophthora sp. caused rots on roots and basal stems were collected from five flowering plants from 1992 to 1997 at eight cultivation areas in Korea. All the isolates were identified as P. nicotianae based on following characteristics. The fungus produced markedly papillate, not caducous and ovoid to spherical sporangia, abundant chlamydospores, and small oospores with amphigynous antheridia only when paired with either A1 or A2 mating type. All isolates grew well at 35$^{\circ}C$ and showed distinct arachnoid colony patterns on CMA and PDA. Sizes of sporangia and chlamydospores of five representative isolates from each plant averaged 43-52$\times$30-38 ${\mu}{\textrm}{m}$ and 28 ~34 ${\mu}{\textrm}{m}$. Mating type of the isolates was either A1 or A2, and oogonia and oospores were measured as 28~31 ${\mu}{\textrm}{m}$ and 21~25 ${\mu}{\textrm}{m}$. PCR-RFLP analysis of rDNA of the five isolates resulted that restriction band patterns of the small subunit and ITS regions were identical to a perilla isolate of P. nicotianae, but distinct from P. cactorum and P. capsici. Cross inoculation tests showed that the five isolates had pathogenicity to lily, christmas cactus, anthurium, baby's breath and carnation with different degrees. However, each isolate showed stronger pathogenicity to its corresponding original host than others. Among five lily cultivars Georgia and Quririna were more susceptible than Napoli and others. This is first report of Phytophthora root and stem rot of lily, Christmas cactus, anthurium, baby's breath and monochoria in Korea.

• 식물병연구
• /
• 제11권2호
• /
• pp.122-127
• /
• 2005

Late blight of potato caused by Phtophthora infestans is one of the most destructive disease in organic farming as well as in the conventional cultivation in Korea. Incidence and progress of the disease largely depend on climatic conditions around the fields. However, the disease completely destroys whole leaves of the plant within two weeks in organic farming fields. While, potato leaves in conventional farming fields remain healthy for 5 weeks after the first symptom appearance, because fungicides were applied four times in average to control the disease. Area under disease progress curve (AUDPC) of organic farming fields ranged from 2314 to 2421 and quickly expanded compare to that of conventional farming fields. The tuber yield in the organic farming fields ranged from 0.96 ton per 10a to 1.5 ton per 10a, while it was 2.7 ton per 10a in conventional farming fields. Tuber yields were reduced to $42\~63\%$ by the infection of late blight and the reduction rate was closely related with the time of first occurrence of the disease in organic farming fields. Physiological races of the pathogen were diversified with R0,1,3,4,5,7,10,11 in organic farming fields at Hongchun area. Pathogen races were distributed with similar pattern at different areas of organic farming fields.

• 한국전자파학회논문지
• /
• 제26권6호
• /
• pp.533-539
• /
• 2015

본 논문은 레이더용 마이크로웨이브 광대역 주파수 대역에서 동작하는 수신단 구성을 위한 재구성 주파수 혼합기를 설계 및 제작하였다. 제안한 주파수 혼합기는 역병렬 다이오드(anti-parallel diode)를 사용하였고, 제어 전압 유무에 따라 기본파 혼합기 또는 부고조파 혼합기로 동작한다. 제작한 주파수 혼합기는 제어전압이 인가된 기본파 혼합 모드에서 X-대역/ Ku-대역으로 동작하고, -10 dB 변환손실, 2.0 dBm P1dB 특성을 나타내었다. 부고조파 혼합모드에서는 Ka-대역으로 동작하고, -17 dB 변환손실, 2.0 dBm P1dB 특성을 나타내었다.

• 한국균학회지
• /
• 제37권1호
• /
• pp.114-116
• /
• 2009

본 연구는 P. capsici의 난포자를 다량으로 확보하기 위하여 우수한 액체 배지를 선발하고 난포자의 발아율을 조사할 뿐만 아니라 $F_1$ progeny를 확보하기 위하여 수행하였다. 공시한 8개 액체배지 중 carrot broth와 V8C broth가 난포자형성을 위해 가장 적당한 배지였다. 총 11균주의 P. capsici(CapA형)과 P. tropicalis(CapB형)를 선발하였고 P. capsici(CapA형)에 P. tropicalis(CapB형)을 교배하는 서로 다른 9개 조합의 교배에서 얻은 난포자로부터 총 129 균주의 $F_1$ hybrid progeny를 얻었으며 난포자의 발아율은 0.64-4.0%(평균 1.85%)이었다.

• Applied Biological Chemistry
• /
• 제45권3호
• /
• pp.157-161
• /
• 2002

새로운 살균제를 개발할 목적으로 새로운 2-benzoylimino-1,3-oxathiole 유도체 3을 합성하고, 그들의 살균활성을 시험하였다. ${\gamma}-Chloro-{\beta}-keto$ anilide 유도체 5를 potassium thiocyanate와 반응시킨 다음 산성 촉매로 처리하여 고리화된 2-imino-lf-oxathiole 3을 얻었다. 새로운 화합물 3을 benzoyl chloride 유도체와 반응시켜 상응하는 2-benzoylimino-1,3-oxathiole유도체 7들을 얻었다. 합성된 화합물 7들의 대표적인 식물병원균인 벼 도열병, 벼 잎 집무늬마름병, 오이 잿빛곰팡이병, 토마토 역병, 밀 붉은녹병 및 보리 흰가루병 등 』6종에 대한 항균력(in vivo)을 시험하였다. 합성된 모든 화합물은 100mg/l에서 특별한 살균력을 나타내지 않았다.

• 한국철도학회논문집
• /
• 제12권2호
• /
• pp.254-259
• /
• 2009

국내 도시철도시스템에서 채용한 직류급전시스템에서 다이오드 정류시스템을 사용하여 역방향 조류가 불가능하다. 이에 따라 전동차의 감속 또는 제동시에 발생하는 회생 전력을 재활용하지 못하고 열에너지로 소비하게 된다. 잉여 회생 전력의 재활용은 에너지 이용의 극대화, 전동차의 제동 성능 향상 및 분진 감소 등의 환경 친화적인 효과를 얻을 수 있으며, 정류기와 역병렬로 인버터를 설치하여 타 계통으로 전달하거나 저장하는 형태로 가능하다. 본 논문에서는 발생한 잉여 회생 전력을 교류 전력으로 변환하여 고압배전계통이나 한전 계통으로 역송전이 기능한 회생용 인버터의 시험 설비 개발 및 성능시험에 대하여 제안하였다. 회생용 인버터 개발 후 개발품의 성능 시험을 위하여 직류급전시스템을 모의할 수 있는 교/직류 전원 설비 및 부하설비를 이용하여 회생용 인버터의 고유 성능을 시험 및 분석하였다.