• Journal of Aquaculture
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• 제11권4호
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• pp.475-485
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• 1998

To clarify annual reproductive cycle of Koran dark sleeper, odontobutis platycephala, we examined the seasonal changes of gonadosomatic index(GSI), testicular development stages and sex steroid hormones in blood from December 1995 to November 1997. Testis was podlike shape from July to October, and tadpole-like shape from November because of its expanded posterior part. GSI was 0.14~0.18 from July to September and increased to $0.43{\pm}0.04$ in October and then was not changed significantly until February. GSI was reincreased to $0.52{\pm}0.09$ from March and then was kept at similer levels until May, but fell down to $0.28{\pm}0.05$ in June. As results of histological observation, testis was divided into 3 parts(anterior, boundary, posterior) in the development progress of germ cells. In July, the testis was composed of only spermatogonia without seminiferous tubules in most fishes. In the anterior part of testis, the ferquency of spermatogenesis stage seminiferous tubules appearing in August was more than 80% from September to December. decreased gradually from January to March and drastically in April, and then disappeared in June. The frequency of spermiogenesis stage seminiferous tubules appearing in December, increased gradually from January to March and drastically to 80% in April, and reached to 90% the highest levels of the year in June. Post-spawning stage seminiferous tubules did not appear throughout the year. The frequency of spermatogonia was 100% and 65% in July and August, and less than 20% in the rest period of the year. In the boundary part, the frequency of spermatogenesis stage seminiferous tubules appearing in August increased from September and reached to 82% in November, decreased from December, adn disappeared in March. The frequency of spermiogenesis stage seminiferous tubules appearing in November was less than 18% until February, and increased to 29%~57% from March to June. The frequency of post-spawning stage seminiferous tubules appeared 12%~25% only from March to June. The frequency of spermatogonia was 100% in July, decreased to 85% in August and 10% in November, and increased gradually from December to 50% in April, and decreased again from May to June. In the posterior part, seminiferous tubules with some seminiferous tubules increased drastically 80%~85% in August and September, decreased drastically from October to November and remained below 10% until February, and disappeared after March. The frequency of spermiogenesis stage seminiferous tubules appearing in August increased sharply from October and reached to 75% in November. decreased to 15% in December and no significant changes until March, and disappeared after April. The frequency of post-spawning stage seminiferous tubules appearing very early in November increased to 82% in December and 85%~95% until June. The frequency of spermatogonia was 100% in July, decreased drastically to 15% in August, disappeared from October to Mrch, but reappeared from April and kept at less than 10% until June. The blood level of testosterone (T) increrased gradually from August was $0.61{\pm}0.09 ng/m\ell$ in November, increrased drastically to $3.99{\pm}1.22 ng/m\ell$ in December and maintained at in similar level until March, and decreased to $0.25{\pm}0.14 ng/m{\ell} ~ 0.17{\pm}0.13ng/m{\ell}$ in April and May and no significant changes until July (P<0.05). The blood level of 17, 20 -dihydroxy-4-pregnen-3-one $ng/m{\ell}$in the rest of year without significant changes(P<0.05). Taken together these results, the germ cell development of testis progressed in the order of posterior, boundary, anterior part during annual reproductive cycle in Korean dark sleeper. The testicular cycle of Korean dark sleeper was as follows. The anterior part of testis : i.e. spermatogonial proliferation period (July), early maturation period (from August to November), mid maturation period (from December to March), late maturation period (from April to May) and functional maturation period (June) were elucidated. The boundary of testis, i.e. spermatogonial proliferation period (July), early maturation period (from August to October), mid maturation period (from November to February) and the coexistence period of late maturation, functional maturation and post-spawn (from March to June) were elucidated. The posterior of testis, i.e. spermatogonial proliferation period (July), mid maturation period (from August ot September), late maturation period (October), functional maturation period (November) and post-spawn period (from December to June) were elucidated. It was showed that the changes of sex steroid hormone in blood played a important roles in the annual reproductive cycle of Korean dark sleeper.

• KAPE Magazine
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• 통권172호
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• pp.28-31
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• 2010

한국농촌경제연구원이 지난 11월 25일에 발표한 축산관측 겨울호에 따르면 한우는 2010년 12월부터 2011년 2월까지 한우 수소 600kg 기준 산지가격은 470~490만원, 12월 돼지고기 kg당 지육가격은 4천100~4천300원으로 전망했다. 또 12월 육계 산지가격은 kg당 1천500~1천700원, 계란은 생산량 감소로 12월~2011 년 2월까지 평균 산지가격은 1천100~1천300원으로 전망됐다. 또 오리는 12월~2011년 2월 3kg당 7천800~8천100원으로 전망했다.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제34권3호
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• pp.229-234
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• 1989

In flue-cured tobacco, the relationships between the quality of tobacco leaves (productivity according to quality grade) and specific meteorological factors were noted showing different significances according to different seasons during the growing period of the tobacco plants. The thick leaf high quality was significantly correlated with average temperature in late April, late May, early July and late July. The degree of contribution was greatest in middle May and lowest in late May. In the highest and lowest temperatures, the relations to leaf quality had similar tendency like in the average temperature; the thick leaf low quality showed opposite tendency relative to the high quality in the degrees of correlations and contributions. Amount of precipitation was significantly correlated with the thick leaf high quality in late April, early May, middle May, late June and late July. The degree of positive contribution was shown in order of late April, middle July and early July, and that of negative one was in order of middle June, early June and late June, respectively. Duration of sunshine period was highly associated with thick leaf high quality of tobacco leaves in all of the growing season except for middle April and middle July. The degree of positive contribution was in order of late May, late April, early July and middle July, and that of the negative one was in order of late June, early May, middle June and middle May.

• Journal of Practical Agriculture & Fisheries Research
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• 제20권1호
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• pp.75-87
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• 2018

This study was carried out to investigate the effects of planting time on the survival rate and growth. Ilex cornuta Lindl., I. aquifolium 'Silver Queen', Ardisia pusilla 'Variegata', and Rhododendron indicum(Satsuki azalea) were planted in pottery pot six times such as April 1, June 1, July 1, August 1, October 1, and December 1 in 2017. The survival rate of I. cornuta Lindl. planted in April, October, and December was 100%, whereas the survival rates were 90% in June, 50% in July, and 60% in August, respectively. The survival rates of I. aquifolium 'Silver Queen' and R. schlippenbachii were also shown about 60% in July and 70% in August, which were lower than in the other planting times at 100%. However, the survival rate of A. pusilla 'Variegata' was shown 100% in the all planting times. The growth rates of plant length, plant height or leaf length or any others of I. cornuta Lindl. were shown 20.0%, 15.5% and 16.5% planted in June, July, and August, respectively, while those planted in April, October and December were 3.2%, 12.3% and 10.7% respectively. Similarly, the growth rates of leaf numbers and plant length of I. cornuta Lindl., A. pusilla 'Variegata', and R. indicum(Satsuki azalea) planted in summer season from June to August for all plat (not only leaf numbers and plant length in was facilitated, while the growth was restrained in planting for spring or autumn. Therefore, the plantation during summer is better for increasing the survival rate and promoting the growth.

• Korean Journal of Fisheries and Aquatic Sciences
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• 제17권6호
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• pp.536-542
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• 1984

Fish eggs and larvae in the western waters of Korea are surveyed during the periods from February to August in 1982. Six species of eggs and forty-two species of larvae are occurred in the survey area. The dominant species occurred during the study periods are Ammodytes personatus, Enedrias sp., Engraulis japonica, Callionymus sp., Gobiidae, etc. Major spawning month and ground of each species are estimated from the data, i.e., occurrence month and abundance of eggs and larvae by survey month and area, as well as the optimum water temperature and salinity for spawning.

• Journal of Korean Society of Forest Science
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• 제99권4호
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• pp.528-533
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• 2010

Cage plots were established in 2008 to find the relationship between combination of tended Japanese red pine sapling and the habitation of Monochamus alternatus, a vector for pine wood nematode. Japanese red pine sapling tended at different times were successively put into the cage, and then the adult of Monochamus alternatus was put in June. Presence or absence of the larva was determined November. Sapling tendings were done at seven successive times in 2009, mid- and late February and March, mid-April, May and June. Some saplings were also tended in mid-October of 2008, the previous year of this experiment. The larva was found in all the saplings tended later than mid-March in 2009. No larva was found in the saplings tended in mid-October of 2008 and those in February of 2009. In case of the combination the by-products of mid-February and late March of 2009 and mid-October of 2008, the larva was found in the by-product of mid-February and late March of 2009, but those in mid-October of 2008 was not. When the saplings tended in mid-October of 2008 and mid- and late February of 2009 were put into the cage singly, the larva was found in all the saplings. Results indicated the mixture of the saplings tended at different times affected the habitation of Monochamus alternatus differently.

• Proceedings of the Plant Resources Society of Korea Conference
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.96-96
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• 2019

쌈용과 장아찌로 많이 이용하며 다양한 효능을 가진 곰취(Ligularia fischeri)의 신품종 중에 항산화 활성이 높은 것으로 밝혀진 '쌈마니' 품종에 대하여 좀 더 구제적인 항산화 활성을 알아보기 위하여 재배지역 및 수확시기별 항산화 성분 및 생리활성 정도를 비교 분석하여 지역별 적정 수확시기를 구명하고자 본 연구를 수행하였다. 시료는 2018년 4월 18일부터 2018년 7월 9일 까지 20일 간격으로 4회에 걸쳐 고랭지인 고령지농업연구소 대관령시험포장과 평난지인 강릉시험포장에서 수확하였으며 모두 동결 건조하여 분말형태로 갈아 실험에 사용하였다. 분석결과 '쌈마니' 품종의 지역 및 수확시기별 수율은 유사하였으며 총페놀 함량은 평난지에서는 5월 9일이 264.7mg GAE/g로 가장 높았고 그다음이 5월 29일, 6월 19일, 4월 18일 순이었다. 대체적으로 5월에 높았으며 고랭지에서도 초기 생산보다는 중기 생산기인 6월 18일에 총페놀 함량이 274.4mg GAE/g로 가장 높았고 그다음이 7월 9일, 5월 28일, 5월 10일 순이었다. 총플라보노이드 함량도 같은 경향으로 평난지에서는 5월 9일에 76.0mg QE/g로 가장 높았으며 그다음이 5월 29일, 6월 19일, 4월 18일 순이었으며 고랭지에서는 6월 18일에 66.5mg QE/g으로 가장 높았고 그다음이 7월 9일, 5월 28일, 5월 10일 순이었다. 재배지역 및 수확시기별 DPPH 활성산소 제거능에서도 평난지에서는 5월 9일과 5월 29일에 효과적이었으며 고랭지에서는 6월 18일에 효과가 있는 것으로 나타나 너무 이른 시기나 늦어지면 활성이 떨어지는 것으로 생각된다. 또한 환원력에 있어서도 평난지에서는 $1,000{\mu}g/m{\ell}$의 농도에서 5월 9일, 5월 29일, 6월 19일에 높은 경향을 나타냈으며 고랭지에서는 6월 18일에 높게 나타났다. 이러한 결과로 볼 때, 쌈마니 품종은 평난지에서는 5월, 고랭지에서는 6월에 수확하는 것이 항산화 활성이 높은 것으로 사료되었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제60권2호
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• pp.153-166
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• 2015

Production of high quality pigmented rice contained with high content of anthocyanin, and polyphenol was significantly influenced by cultivation environments like transplanting date and cultivation location. This study was carried out to establish an optimum transplanting date and cultivation region to produce maximum content of anthocyanin, polyphenol and antioxidant activity of pigmented rice varieties (black, red colored). Three transplanting times (May 20, June 5, June 20) and four different sites (Miryang, Uiseong, Sangju, Bonghwa) were evaluated with five pigmented rice cultivars. Anthocyanin and total polyphenol index to average temperature during 30 days after heading (DAH) of black, red pigmented rice varieties showed that anthocyanin and total polyphenol contents were decreased by 10% and 9%, respectively, with increasing average temperature of $1^{\circ}C$. The optimum ripening temperature of the 30 DAH for the production of high anthocyanin and total polyphenol was 22 to $23^{\circ}C$ for early maturity black rice, 21 to $22^{\circ}C$ for mid-late maturity of black and red rices, respectively. On the other hand, an estimated heading date of pigmented rices in return according to the optimum ripening temperature of the 30 DAH was ranged Aug. 11 to 17 for early maturity black rice, Aug. 25 for mid-late maturity black, red rice variety in Jecheon, Aug. 27 to Sep. 2 for early maturity type, Sep. 3 to 6 for mid-late type in Daegu. It seemed that Jecheon, Boeun, Mungyeong, and Yeongju were optimum regions for cultivation of pigmented rices. The estimated sowing date of pigmented rices for high anthocyanin and total polyphenol production based on the optimum heading date was May 18 to 26 for early maturity black rice variety, April 11 for mid-late black, red variety in Jecheon, May 23 to 28 for early type, April 9 to 26 for mid-late type in Boeun, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제40권1호
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• pp.120-124
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• 1995

The study was conducted to investigate the relationships between tobacco leaf pro-duction rate by quality grade and the value of climatic factors in tobacco growing season. In flue cured tobacco（NC82）, high quality was positively corretated with precipitation in late April and May, with sunshine' hours in early May and late June, with average temperature in middle July, significanly. In Burley tobacco（Br21）, high quality was positively correlated with precipitation in late April and May, with sunshine hours in early May and early July, with average temperature in middle July, significantly.

• Korean journal of applied entomology
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• 제29권3호
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• pp.176-179
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• 1990

Seasonal occurrence in each stages of rice water weevil, Lissorhoptrus oryzophilus Kuschel, was studied in paddy field transplanted on May 25, Siehung, 1989. The peak of overwintered adults was late May an that of newly emerged adults was early August. Oviposition occurred in late May and late June and its peak was observed on early June. Larvae were observed from early June to early August and pupation occurred from early July to late August. The first adults of newly emerged rice water weevil was observed on early July and its emergence peak was early August.