• Korean journal of applied entomology
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• v.47 no.4
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• pp.385-394
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• 2008

Larvae of Monochamus saltuarius showed normal growth and development on conifers of Pinus koraiensis, P. densiflora, Abies holophylla, Larix leptolepsis, P. bungeana, and P. rigida, respectively, but the conifers influenced significantly the body weight and the survival rate of larvae. Though the larval body weights were in a wide spectrum among treatments, growth curves of them were very similar from each other, showing continuous increase from the early larval stage to about 3 months old. The body weight was decreased slightly after the feeding period of the early 3 months. The size of larvae and adults became the largest from P. bungeana fed larvae. The mid-sized ones were from P. koraiensis, P. densiflora and A. holophylla. Small ones came from L. leptolepsis and P. rigida. The larval growth was retarded without water supply. Overall survival rates from the early stage of a larva to a fertile adult were 53.6% from P. koraiensis; 51.8%, P. densiflora; 34.7%, A. holophylla; 17.8%, P. bungeana; 16.7%, L. leptolepsis; and 12.3%, P. rigida. Adults from larvae fed the 6 species of conifers, respectively, were grown into the reproductively potent adults, which laid viable eggs. A few of overwintered larvae did not pupate and remained still as a larva until the late October of the year. Data from the field survey, the head width emerged from P. koraiensis was larger than that of L. leptolepsis. The adult emergence hole in P. koraiensis was larger also. While, the size of the emergence hole was larger in the artificially innoculated log of P. koraiensis, which was kept for a larva to be with a minimized food competition and sufficient water supply, than that of the field.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.282-291
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• 2014

This study was conducted to make distribution model of the Red-crowned Crane and the White-naped Crane according to the anthropogenic and natural factors affecting distribution of crane in Cheorwon, Korea. It was investigated that the impact power and its range of the indirect anthropogenic influence to feeding flock density in cranes from the road, residential area, military facilities, civilian control zone (CCZ), greenhouse and natural influence such as roosting site and available feeding area. Available feeding area is the most important factor for the crane's feeding site selection. The feeding flock density of the cranes near the residential area was lower than that of area far from the area, and tended to increase within 2.5 km distance. The increasing tendencies of feeding flock density from military facilities and high traffic volume road were similar, but the density in military facilities increased within 800 m, and the density from high traffic volume road increased within 2 km. These results suggested that residential area, military facilities and the road with high traffic volume had significant effect on foraging densities to the certain range. As the distance from the road with low traffic volume and roosting site increased, feeding flock density tended to decrease. The density of Red-crowned crane and White-naped crane inside the CCZ were respectively higher than those of outside the CCZ, especially for the Red-crowned crane. As a result, density of Red crowned cranes inside the CCZ was 5.2 times higher than that of outside, while that of white-naped cranes was 2.2 times bigger. If the density of greenhouse is lower than $40km^{-2}$, crane's feeding flock density in the low greenhouses density area was higher than that of high greenhouses density area. However, there was no difference in the feeding flock density if the density of the green houses is higher than $40km^{-2}$. The model for the Red-crowned Crane was related with available feeding area, distance from residential area, civilian control zone and distance from high traffic road. The model of the White-naped Crane was related with available feeding area, distance from roosting site and distance from lake. Finally, the estimated feeding flock density of cranes significantly correlated with density model according to the natural and anthropogenic factors.

• Journal of Korean Society of Forest Science
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• v.83 no.3
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• pp.311-321
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• 1994

Experiments were conducted to evaluate the efficacy of ground and foliar sprinkling of natural water for control of the pine needle gall midge, Thecodiplosis japonensis, by disturbing the reproductive behavior of adults such as copulation and oviposition. Diurnal ground spray for whole area application and foliar spray for single tree treatment were tested at day time during the period of adult emergence. The results obtained are as follows : 1. The population density of overwintering larvae in soil was not affected by the water spray during the adult emergence period. 2. Spraying the water showed no effect on the whole period and number of adult emergence, but retarded early emergence and facilitated Late emergence. The difference in the emerging time by 50% emergence day was approximately 7 days. 3. Ground spray was significantly different from control in gall formation rates but was not sufficient for effective control. As a single-tree treatment, the foliar spray was found to be highly effective for control of the pine needle gall midge, Average gall formation of spray plots and untreated ones were 2.6% and 38%, respectively ; control value exceeded 90%. 4. Ground spray of water was not effective in reducing larvae in gall of needle. Foliar spray, however, reduced 45% of larval numbers. 5. Foliar spray accelerated shoot growth by 15%-18%. 6. Foliar spray was highly effective for the control of sucking insects, such as mites and aphids on pine trees.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.297-297
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• 2009

최근 유기농산물에 대한 관심과 요구가 급증하면서 소비자들은 고품질 유기농산물을 선호하고 있어 국내 대부분 유기농가들은 무처리 일반종자를 이용하고 있는 실정이다. 앞으로 국제 기준에 부합하는 채소류 유기재배를 위해서는 유기종자의 이용이 필수적이므로 유기종자 채종체계 확립이 필요한 실정이다. 따라서 본 연구에서는 당근 종자(재래종 heimloom)를 사용하여 유기종자의 채종체계를 확립하고자 하였다. 일반적으로 당근종자 생산은 적어도 2년을 요구한다. Seed to seed 방법과 Root to seed 방법이 이용되고 있는데 본 연구에서는 Root to seed 방법을 사용하였다. Root to seed 방법은 6월에 당근종자를 파종하여 가을에 뿌리를 수확하여 지상부를 5cm 정도 남기고 정지하여 일시 저온저장 하였다가 이듬해 뿌리를 이식하여 새순에서 추대시켜 종자를 수확하는 방법으로 종자 생산성이 높아 종자회사에서 많이 사용하고 있다. 본 연구에서도 Root to seed 방법으로 채종 시험하였다. 2008년도에 파종 및 수확한 뿌리를 저온저장고에 일시 저장 후 1차 이식은 2008년 11월 하순에 노지포장에서 실시하고 이때 월동 중 동해를 막기 위하여 보온덮개로 멀칭 처리하였다. 이듬해 3월 중순에 주간거리 75${\times}$40cm 간격으로 솎음하여 처리당 10주씩 배치하였다. 이식후 뿌리에서 새순 1대를 유도하였고 추대 및 개화 6주후부터 종자가 갈색으로 변하기 시작할 때 채종을 시작하였다. 수확부위는 1차 측지 중 1번째 화지를 대상으로 하였고 화경절단은 화총으로부터 20cm 정도 남겨서 잘랐고 실내에서 1개월 이상 충분히 후숙시킨 후 종자를 정선하여 종자생산성을 조사하였다. 결실율과 발아율 조사는 채종된 종자를 이용하여 종자 충실도와 발아력을 조사하였다. 각 품종별 추대율은 15번 품종과 16번, 24번 품종이 5% 미만으로 매우 부진하였고 그밖에 추대된 묘의 생육 및 발육상은 매우 양호하여 개화에는 커다란 문제가 없었다. 종자 결실율은 23번 품종을 제외한 모든 품종에서 높았고 각 품종별 화총구조를 고려해 볼 때 주간 화총, 1차측지, 2차측지 순으로 결실율이 떨어졌다. 각 품종의 천립중은 1, 11, 12, 14, 20번 품종이 2.02g 이상으로 대립종으로 판단되며 각 품종별 화총의 크기는 비슷하여 대립종은 각 화총당 종자수가 적은 것으로 나타났다. 대분분의 대립종은 만생종으로 생육기간이 소립종 보다 10-20일상 길며 종자 성숙기간도 장기간 소요되며 특히 장마기간을 넘겨야 할 경우에는 비가림 시설 채종재배가 필수적인 것으로 나타났다. 발아율은 10, 11, 14, 18, 19, 26번 품종이 80% 이상으로 가장 높았고 다른 품종에서는 다소 떨어져 품종별 차이가 많았다. 종자 생산성은 장근종과 단근종간에 약간의 차이가 있지만 주간 화총을 포함하여 1차 측지 4-5개에서 채종하는 것이 가장 효율적인 것으로 사료된다. 또한 당근의 개화 기간을 보면 1화륜은 8~10일, 1개체는 40~50일, 채종포장에서는 1화륜에서 측지 6개구까지 채종은 60~70일 소요되어 미숙종자와 과숙종자가 혼재되어 적정 수확시기를 결정하기가 매우 어려운 점이 발생하였다. 본 연구 결과에서 생육특성, 수량성, 품질특성, 종자 생산성, 발아율을 고려해 볼 때 1, 7, 8, 9, 10, 14, 19, 26번 품종이 유기농 재배 및 유기채종에 적합한 것으로 사료되었다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.6
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• pp.509-519
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• 1987

Annual reproductive cycle of the Damselfish, Chromis notatus collected monthly at the four coastal areas around Chejudo, Korea are studied on the bases of histological observations of gonadal tissue and various quantitative variables including gonadosomatic index (GSI), fatness, egg diameter composition and the first maturity. The ovary consisted of a pair of saccular structure with many ovarian sacs. Oogonia proliferated along the germinal epithelium of the ovarian sac. Young oocytes with basophilic cytoplasm showed several nucleoli along the nuclear membrane. When the oocytes reached about $450{\mu}m$ in diameter, nucleus migrate toward the animal pole, nuclear membrane disappeared and most of cytoplasm were filled with yolk materials and oil drops. After ovulation, residual follicle and growing oocytes remaining in the ovarian sacs degenerated. But early young oocytes without follicle layer were not degenerated, and growing continuously till the next year. The testis consisted of a pair of lobular structures in the right and left were united in the posterior seminal vesicle. Cortex of testis was composed of many sperm ducts connected with lobuli. GSI began to increase from March, starting season of longer day length and higher water temperature, and reached the maximum value between June and August. It began to decrease from September with the lowest value appearing between October and February without any evident variation. The annual reproductive cycle could be devided into five successive stage : growing(April to Many), mature(May to August), ripe and spent (June to August) and recovery and resting stage(September to March). The spawning peak occurred from June to August. According to the frequency distribution of egg diameter, Chromis notatus was a polycyclic species to spawn twice or more in a spawning season. Fatness, correlated with gonadal phases, was remarkably decreased by spawning. Percentage of the first maturity . in femate and male fish ranging from 7.0 to 7.9 cm were $50\%$ and from 9.0 to 9.9 cm in total length $100\%$.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.1
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• pp.30-38
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• 2018

This study was conducted to explore the effects of seeding rate of a seed mixture on grassland productivity and botanical composition. Seeding rates were composed of four different treatments varying by the amount of seed: T1, 50% decrease in seeding rate from standard; T2, standard seeding rate; T3, 50% increase in seeding rate from standard; and T4, 100% increase in seeding rate from standard. In 2016, seasonal changes in grass botanical composition revealed T2, T3, and T4 in portion of grass ratio were the highest with a range of 87-100%, whereas T1 was the lowest of all treatments. In 2017, the botanical composition in T1 showed that the grass ratio in of the first cutting was 91%, but in the fourth cutting its ratio decreased by 75%. The results from both years were combined for each treatment, T4 ($11,435kg\;ha^{-1}$) and T3 ($11,162kg\;ha^{-1}$) demonstrated the highest dry matter yield of the treatments (T1: $8,196kg\;ha^{-1}$; T2: $9,521kg\;ha^{-1}$) (p<0.05). As a result, a 50-100% increase in the seeding rate from the standard demonstrated the best grassland yield and botanical composition.

• Journal of The Korean Society of Grassland and Forage Science
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• v.39 no.1
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• pp.24-30
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• 2019

This study was conducted to investigate the effect of seeding dates on grassland productivity and botanical composition in oversown pasture located in Cheonan of South Korea. Four treatment groups were established based on the seeding dates: 18th August, 1st September, 15th September and 29th September. Evaluation of seasonal changes in botanical composition of pasture showed that the highest ratios of grass in 18th August and 1st September (pasture species 93% and weeds 7%) and the lowest in 15th September (pasture species 75% and weeds 25%). In the plant length, there is no significantly different in 5% probability level. In the total dry matter yield of grass, 18th August ($13,362kg\;ha^{-1}$) and 1st September ($13,988kg\;ha^{-1}$) were higher than 15th September ($11,883kg\;ha^{-1}$) and 29th September ($11,459kg\;ha^{-1}$). The findings of the this study suggest that seeding by early September the most desirable results for botanical composition and grassland productivity in oversown pasture, Cheonan of South Korea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.3
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• pp.145-154
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• 2009

Seasonal variation in species composition and abundance of shallow water fish from the Hakampo and Yeonpo beaches in Taean in the western coast of Korea were determined by the analysis of monthly samples collected by a beach seine from January to December, 2007. A total of 30 species, 964 individuals and 10,564.1 g of fish were collected from the Hakampo beach, and a total of 46 species, 4,447 individuals and 28,622.4 g of fish from the Yeonpo beach. The juveniles of coastal fish such as Chelon haematochelius, Paralichthys olivaceus, Repomucenus lunatus, Sebastes schlegelii and Takifugu niphobles were predominated in abundance. And the juveniles of pelagic migrants such as Konosirus punctatus, Sardinella zunasi and Engraulis japonicus were abundantly collected between summer and autumn. The fish collected were mainly composed of small-sized species and juveniles. C. haematochelius and migrant fish were young of the year, and commercially important fish such as S. schlegeli, P. olivaceus, Pleuronectes yokohamae and Hexagrammos otakii were 1 to 2 years old juveniles. It is considered that they use the shallow water as a nursery ground until they move out to the deeper water. The number of species and abundance were lower in the fine sand Hakamp beach than in the muddy sand Yeonpo beach where some Zostera marina were also found. In Yeonpo beach the adult of Gymnogobius mororanus preferred to live in the muddy shallow water and Syngnathus schlegeli living in the sea grass were also abundantly collected in spring in addition to resident fish and pelagic migrants in warm months. The resident species were more abundance in the Taean beach than in the beach located in the southern part of the west coast of Korea where the juveniles of pelagic migrants were more abundant.