• Journal of Korean Society of Environmental Engineers
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• v.35 no.3
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• pp.213-219
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• 2013

We have investigated the correlation between odorous compounds and actinomycetes in drinking water source of Nakdong River in 2011. Geosmin was mainly detected in the spring and summer seasons (Mar, Aug, and Sep) and 2-MIB was mainly detected in the winter and spring seasons (Feb, Mar and May). The odorous compounds concentrations were highest on March which also overlapped with the peak of actinomycetes, geosmin and 2-MIB were detected highly in the diluted culture solution of isolated actinomycetes strains from Nakdong River. For these reasons we could confirm that odorous compounds on March and August are closely related with actinomycetes. Meanwhile, geosmin increase on September supposed to relate with Microcystis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.439-442
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• 2001

This study has been conducted from April 25, 1999 to June 25, 1999 in Jeju Province in order to determine the influence of seeding date on growth, yield and chemical composition of Kenaf (Hibiscus cannabinus L.) Delaying the seeding date from April 25 to June 25 decreased the plant height of Kenaf from 278.5 cm to 205.7 cm. As for the number of leaves, number of withering leaves, number of branches, and stem diameter decreased as the seeding date was delayed. As the seeding date was delayed, fresh forage yield decreased from 98.5MT/㏊ to 45.9MT/㏊, dry matter yield from 20.7MT/㏊ to 8.2MT/㏊, crude protein (CP) yield from 2.9MT/ha to 1.3MT/ha and total digestible nutrients (TDN) yield form 1l.6MT/㏊ to 5MT/㏊. However, both leaf yield and stem yield were nearly the same tendency. Delaying the seeding date from April 25 to June 25 increased crude protein contents of leaves from 21.5％ to 24.4％, crude fat contents from 5.2％ to 6.1％, nitrogen free extract (NFE) contents form 39.9％ to 41.2％ and TDN contents from 64.3％ to 69.7％. However, delaying seeding date decreased crude fiber contents from 20.8％ to 17.5％, and crude ash contents from 7.9％ to 7.0％. Based on the these findings, optimum seeding date for forage production of Kenaf seems to be about 25 April in atmospheric phenomena and volcanic ash soils of Jeju island.

• Korean Journal of Medicinal Crop Science
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• v.3 no.1
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• pp.1-4
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• 1995

To determine the optimum sowing time and nursery period in Perilla frutescens in the southern areas of Korea, perilla frutescens cv. red Perilla local cultivar was grown under three different sowing dates and nursery periods. The blooming period of the area which was sown on the seedbed in Apr.10 and carried out the growing seedling in 30days is Aug. 12 and it is two days earlier than that of the area, Aug.14, sown on the seedbed in Apr. 20 and carried out the growing seedling in 30days of the same month and it is also six days earlier than that of the area, Aug.18, sown on the seedbed in April 30 and conducted the growing seedling in the same date. The stem lengths are 135cm,131cm and 125cm respectively and the number of branches are 26.4, 25.3 and 23.6 respectively. The fresh weight of stem and leaf at the area sown on the seedbed in Apr.10 and conducted the growing seedling in 30days with the width of leaf over 5cm in the middle of Aug. and at the beginning of Sep. is 2,476kg/10a and it shows more increase of 172kg than that of fresh weight of stem and leaf with 2,304kg/10a which was sown on the seedbed in Apr.20 and earned out the growing seedling in 30days, and it also shows more increase of 411kg than that of fresh weight of stem and leaf with 2,065kg/10a at the area sown on the seedbed in April 30 and con­ducted the growing seedling in the same date, The fresh weight of seeds are 609.5kg/10a,509.3kg/10a and 463.2kg/10a respectively and $100.2{\sim}146.3kg$ is more increased. Therefore, the seedling period of the proper seedbed for high yield bumper crop of perilla frutescens for exporting to Japan is April 10 and the number of days for seedling is 30 days.

• Korean Journal of Environmental Biology
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• v.24 no.3
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• pp.258-267
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• 2006

Distribution of population densities of heterotrophic bacteria, E. coli, and Salmonella and Shigella in seawater and sediments at 40 stations near Samcheonpo Bay were measured for 3 times from July to December, 2003. Population densities of heterotrophic bacteria in seawater during survey periods were in the range of $1.7{\pm}0.9{\times}10^3{\sim}2.4{\pm}0.9{\times}10^5$ CFU $mL^{-1}$ and the highest density was shown at St. 34 during the sampling period of September, 2003. Population densities of heterotrophic bacteria were shown higher values on September than those of July and December at all sampling stations. Population densities of anaerobic heterotrophic bacteria in sediments during survey periods were in the range of $2.2{\pm}0.2{\times}10^3{\sim}2.0{\pm}0.2{\times}10^5$ CFU $mL^{-1}$ and their population densities at sampling stations far from Samcheonpo Bay measured lower values than those near Samcheonpo Bay. Population densities of anaerobic heterotrophic bacteria in the sediments were not affected by physico-chemical factors of upper water environment. E. coli were detected only at 8 stations in seawater and 4 stations in the sediments among 40 sampling stations on July and were not detected during September and December. Salmonella and Shigella were detected only a few stations on July and September during sampling periods.

• Development and Reproduction
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• v.7 no.1
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• pp.23-28
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• 2003

The seasonal reproductive cycle of the female honeycomb grouper, Epinephelus merra, inhabiting Chuuk was examined by histological observations of the ovaries. The gonadosomatic index (GSI) began to increase in February and peaked in March. Histological observations revealed many oocytes laden with yolk in the ovaries from March to April. From June to January, the ovaries were occupied by immature oocytes. These results suggest that the reproductive season of E. merra in Chuuk is from March through April.

• The Korean Journal of Malacology
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• v.13 no.1
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• pp.55-64
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• 1997

꼬막, Tegillarca granosa은 우리나라 남해 및 서해안 일대에서 서식하는 중요한 수산자원 중의 하나이지만, 이에 대한 생물학적 기초연구는 거의 없는 실정이다. 따라서 1995년 2월부터 1996년 1월까지 전남 벌교연안에서 채집한 꼬막의 생식소발달, 생식세포형성과정 및 생식주기를 조사하였다. 1. 꼬막은 자웅이체이면서 난생이고, 생식소는 내장낭의 간중장선을 싸고 있는 결합조직으로부터 족부의 근육층까지 분포한다.2. 미분화간층직과 호산성 과립세포들이 초기 활성기의 소낭에 풍부하게 나타나기 시작하여 완숙기에는 거의 없어지는 것으로 보아, 이들은 생식소 및 생식세포형성과 발달에 영향을 공급하는 영향세포로 생각된다.3. 생식소발달, 생식세포형성과정, 조직분화과정 및 세포학적 특성에 따라, 이들의 생식주기를 초기 활성기, 완숙기, 부분 방출기, 방출 및 비활성기 등으로 구분할 수 있다. 4. 방란 및 방정은 수온 2$0^{\circ}C$정도되는 6월하순부터 시작되고, 주산란시기는 수온이 23-24$^{\circ}C$정도 되는 7-8월이며, 완숙란의 크기는 50-60$\mu\textrm{m}$이다.5. 비활성기는 9월에서 이듬해 4월까지 지속되는 비교적 긴 기간이며, 초기 활성기도 비교적 길어 1월에서 5월까지 지속되는 반면, 후기활성, 완숙 및 방출기는 비교적 짧아, 5월에서 8월까지 모두 완료된다.6. 비만도의 월별 변화는 생식소의 발달, 생식주기 및 수온과 밀접한 관계가 있다.7. 사용된 재료 433개체 중 1개체가 자웅동체현상을 나타내었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.211-215
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• 2002

This study was carried out to find out the optimum harvesting time on the basis of physiological characteristics, yield and commercial value in four years old ginseng. For this purpose, the changes of agronomic growth characteristics of the aerial and underground parts with different growing stages were examined with fourth year ginseng. The leaf growth was dramatically increased from the mid-April (shooting stage) to the mid-May (flowering stage), and the growth was nearly completed by the mid-May, but the stem growth continued by the mid-August. The weight of fresh root decreased from the April (20.7g) to the June (18.2g), but increased from the June to the October(45. 1g). The yield of fresh root per "Kan" was 1.5 kg, 1.2kg and 1.3kg at the April, the May and the June, respectively, thereafter continually increased to 2.9 kg of the October, which showing the maximum yield. In conclusion, the ginseng root was generally harvested from the September to the October at farm-house, but it had better be harvested after the mid-October rather than from September to October considering the weight of dry root and the yield of fresh ginseng.h ginseng.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.6-18
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• 2001

Larvae of the gunnel Pholis fangi were collected in coastal waters off Daecheon with a bag net from March to June, 1988, and with a ring larva net in February 1989. Maturity and spawning period were analyzed by examination of the gonads of adult fish collected with a bag net from May 1998 through November 1999. In February, the larvae were widely distributed in the outer and inner Cheonsu Bay. From March to April the larvae were present mainly the inner bay; they were absent there in May and found mainly in the outer bay. After June, few gunnel larvae were collected in the study area. This suggests a seaward movement of gunnel from the nursery grounds of the bay to offshore feeding grounds. The otolith of larvae smaller than 10 mm in total length did not show a distinct growth stop. The growth stop is believed to be formed in the early larval stage when the total length is about 10 mm. This period coincides with the time of shoreward migration, suggesting a metabolic change during this period. At a total length of 30 to 40 mm, the shape of the otolith changes from spherical to elongate. Daily growth rate in length was estimated by the Gompertz equation, which is represented as follows: TL = 6.702exp{2.925"1-exp (-0.008 t)"} ($r^2=0.94$, N = 92) Assuming daily deposition of growth increments in the otolith, the time of first growth increment formation was shown to be from December to January. Gonad observations show that Pholis fangi spawns from November to December. So, the hatching time is thought to be about one month.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.807-811
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• 2015

This study was conducted to identify the air temperature factors that affect leafing date of mulberry (Morus alba) in Buan, Jeonbuk province. Over the period from 2009 to 2014, the leafing date averaged April 24 (114 Julian days). The earliest leafing date was April 12, in 2014, and the latest leafing date was May 2, in 2011. Yearly variations of daily mean temperature (DMT) and daily maximum temperature (DMxT) were high in the last part of March. There were highly negative correlations between leafing date and degree days of accumulated DMT above 0, 5, and $10^{\circ}C$ in the period from March 1 to April 10. Linear regression equations for estimating the leafing date were y = 153.8 - 0.1886 ${\times}$ ($r^2=0.965^{**}$) and y = 126.2 - 0.2246 ${\times}$ ($r^2=0.825^*$) for the degree days of accumulated DMT above $5^{\circ}C$ in the period from March 1 to April 10 and the last part of March, respectively. Therefore, leafing date of mulberry, which is important for popcorn disease control, is 96.5% predicted by degree days of accumulated DMT above $5^{\circ}C$ in the periods from March 1 to April 10.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.90-90
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• 2018

고사리(Ferns)는 고사리 속(Pteiidium spp.)에 속하는 양치식물의 총칭으로서 우리나라에는 22과 70속 272종이 분포되어 있는 것으로 보고되었다. 고사리의 어린 순에는 가식부 100g 당 칼슘 15.0mg, 칼륨 185.0mg 등이 함유되어 있으며 골다공증, 심혈관질환 등에 효과가 있고 식이섬유로 인해 변비 예방에도 유용한 것으로 알려져 있다. 2017년 기준 우리나라의 고사리 재배면적은 3,280ha 수준으로 그중 전라북도의 고사리 재배는 재배면적 285ha이며 연간 생산량 1,985톤으로 전국 생산량의 21%를 차지하고 있어 전라북도의 산채 재배작목 중 중요한 비중을 차지하고 있다. 고사리 재배는 정식 후 수확기간이 길고 제초노력 등의 노동력 의존도가 상대적으로 낮아 최근 재배면적이 늘어나고 있는 추세이나, 종근의 적정 규격 등에 대한 기준이 제시되지 않아 경영비 부담이 큰 실정이다. 본 연구는 고사리 종근 규격을 종근 두께 기준 A등급($14.1{\pm}3.31mm$), B등급($8.3{\pm}1.88mm$), C등급($3.3{\pm}2.31mm$)로 구분하여 표고 500m의 허브시험장 연구포장에 3월 28일 정식한 후 2018년 4월부터 신초 출현양상 및 수량성을 조사하였다. 파종 2년차 고사리 신초의 출현양상은 4월 11일부터 출현을 시작하여 6월 11일 까지 빠르게 증가하여 7월 9일 이후 고온기이후 증가세가 완만해지는 경향을 보였고 9월 10일까지 누적 신초수는 A 등급 파종구에서 80.0개를 보였다. 신초 출현 후 포자엽이 전개되어 상품성을 상실하기까지의 포자엽 전개일수는 주 수확시기인 4~5월에는 5.3~6.7일이 소요되었으나, 포자엽 전개이후 울폐가 이루어지는 8~9월에는 9.7~11.7일이 소요되어 생육 초기 차광에 의한 전개일수 연장효과가 기대되었다. 생육기간 동안 조사시기별 신초의 두께는 6월 11일과 9월 11일 조사한 신초에서 굵어지는 경향을 보였고, 상품성 있는 고사리 신초의 규격을 신초장 20cm로 포자엽 전개 직전으로 한정하여 수확을 실시한 결과 파종 2년차 수확은 4월18일 이후 4회 이루어졌으며 신초의 생체중은 5.2~6.0g/개의 범위로 종근 규격 간에는 차이가 인정 되지 않았다. 4월 18일에서 5월 8일까지의 수확기간 동안 누적 신초 수확량은 A 등급과 B 등급의 종근을 파종한 처리에서 각 32.2개/$m^2$, 30.3개/$m^2$로 C 등급 파종구에 비해 유의하게 수확 신초수가 증가하였다. 단위면적당 신초 수량성은 4월 30일 3회차 수확시부터 종근 규격간 차이가 있었으며 누적 신초수량은 A 등급과 B 등급 파종구에서 각 183.3kg/10a, 169.9kg/10a로 유의하게 높았는데 이는 파종된 종근의 두께에 따라 상품성 있는 신초 출현수가 유의하게 증가된 때문으로 판단되었다.