• Journal of the Korean Society of Environmental Restoration Technology
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• v.2 no.4
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• pp.47-53
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• 1999

In order to elucidate physiological factors involved in causing the winter injuries of evergreen Japanese rhododendron (Rhododendron obtusum cv. Hinodegiri) and semi-evergreen rhododendron (Rhododendron yedoense var. poukhanense), these studies were conducted from late winter to early spring. The results were summarized as follows; The water potential, water content in stem, water potential and content have continuously increased in both species between February and May. In R. yedoense, shading treatment had 0.3MPa upper water potential and 3% upper water content than the control. Rhododendron obtusum, the treatments with shading had 0.9MPa upper water potential and 11% upper water content that the control. The difference of water balance by treatments could be found in vitality of stem measured by TTC test. Especially R. obtusum in the treatments with shading in has higher vitality than the control. we find that winter damage of evergreen R. obtusum was determined by whether water balance could be recovered from water deficient state during the dehardening period, or not. In order to recover of the water balance, decreasing water loss more important than increasing water supply, and that was effectively acrueved by the treatment with shading.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.123-128
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• 1986

The characteristics such as characters of seed, fruit and endosperm, development of embryo, dehisced and germination rate of seeds which harvested at 10 days intervals from 20 days to 60 days after pollination were determined to clarify the optimum time for seed production of ginseng. The sizes of length, width and thickness of fruits, seeds and endosperms investigated on 20 days after pollination were not largely different from those that harvested after 60 days. But the weights of fruits and seeds were increased along with the delay of harvesting time. The seeds which harvested from 30 to 60 days showed comparatively high dehisced and germinated rates, especially 40 days in dehisced rates and 50 days in germinated rates. The embryos were rapidly grown in early stage. Lengths of the embryo on 20 days after pollination were approximately grown to 30 ${\mu}{\textrm}{m}$. And after 30 days pollinated, embryos were not only more rapidly grown to 213 ${\mu}{\textrm}{m}$ but also cotyledon premodia were developed in this time and completely formed after 40 days.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.78-78
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• 2018

패션프루트(Passiflora edulis)는 브라질이 원산지이며 아열대와 열대지역에서 재배되고 있는 다년생 상록덩굴식물로 시계꽃과(Passifloraceae) 시계꽃속(Passiflora)에 속한다. 전 세계적으로 500여종이 분포하고 그 중 10여종은 식용, 나머지는 관상용으로 이용되고 있다. 지구온난화로 인한 기온상승으로 전남지역 재배에 적합한 대체 아열대과수 개발이 필요하다. 패션프루트는 겨울 최저온도가 $3^{\circ}C$이상 조건에서 재배 가능하여 남부 지역는 무가온 하우스재배를 하고 있지만 시설내 6월 하순부터 8월 중순까지 $35^{\circ}C$ 이상 고온이 지속되어 과실을 볼 수 없다. 8월 하순부터 피는 꽃은 인공수분으로 착과되어 11월부터 수확이 가능하지만 이후에 낮은 온도($10^{\circ}C$이하)로 착색이 진행되지 않아서 동해피해로 수확을 포기해야 한다. 어느 시기까지 인공수분을 해야 당년에 안정적인 수확이 가능한지를 알아보고자 패션프루트의 후기(2차) 개화시기 중에서 8월 30일, 9월 10일, 9월 20일, 9월 30일에 인공수분 하여 11월 하순에 착색이 정상적으로 진행되는 처리를 조사한 결과 8월 30일 처리구만 11월 21일 착색이 되었다. 미착색과에서 내용물이 진노랑색으로 진행되면 후숙하여 상품과로 판매가 가능하기 때문에 진노랑색에 도달한 시기를 조사하였다. 조사에서 9월 10일까지 인공수분 처리한 과실은 후숙하여 상품과로 판매가 가능하였다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.176-180
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• 2000

The higher sugar and lower starch in super sweet corn may be due to modified endosperm genes sh, bt series, but its seeds have major limiting factors causing low germination and low seedling vigor, This study was conducted to determine what measurable kernel characteristics during the grain tiling period might be more useful as a guide to optimize harvest date for good seed quality in hybrid super sweet corn production. Artificial crossing in super sweet corn hybrid (Chodangok 1) was made on the same day, and ears were harvested from 18 days to 53 days after pollination at weekly intervals. Kernel weight, moisture content, hardness, endosperm rate, seedling height and storage nutrients such as sugars, protein, starch, and germination rate were measured for the kernels at each harvest. Super sweet corn hybrid, Chodangok 1 presented satisfactory germination rate above 70% when harvested on 39 to 46 days after pollination. Its storage nutrients at that time were 23.7-24.2% in starch content 5.5-5.9% in total sugars, 38.9-46.6% in kernel moisture, and 62.7-64.2% in endosperm rate. Germination rate was extremely high when harvested on 39 days after pollination. The black layer of Chodangok 1 could not be used as an indicator for seed harvest. These results suggested that optimum harvest date seems to be 39 days, and kernel moisture and starch content could be used as indications of kernel maturity in deciding when to harvest fer good seed quality in super sweet corn.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.1686-1690
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• 2010

우리나라 면적의 약 67%에 이르는 660만ha의 산림 중 침엽수림은 혼효림을 포함하여 약 74%를 차지해 활엽수림보다 넓게 분포하고 있다. 이와 같이 넓은 산림은 가뭄, 홍수와 같은 수문현상과 관련이 있으며 강우에 따른 유출에의 기여하는 바가 클 뿐만 아니라 강우, 증발산, 침투 유출에 이르는 다양한 수문현상이 복합적으로 나타난다. 특히, 최근 임목밀도의 증가가 오히려 증발산량의 증가, 옆면에 의한 강우 차단량의 증가 등을 발생시켜 가뭄과 홍수 또는 산사태의 원인이 될 수 있으며, 수자원 함양을 저해하는 요소로 작용하고 있다는 우려의 목소리가 나오고 있다. 따라서 산림지역의 증발산과 관련 있는 토양수분의 지속적인 모니터링과 감쇄특성 및 토양수분 환경에 대한 연구는 중요한 요소 연구가 될 수 있다. 봄에서 여름으로 진행되는 시기에는 강우발생에 비해 수목의 생육이 활발하여 증발산에 따른 토양수분 변화 및 감소가 급격하게 일어나며, 여름에는 토양수분의 감소도 뚜렷한 반면, 강우사상도 많이 발생하여 이에 따른 변화폭이 크게 나타난다. 또한, 가을에서 겨울로 진행되는 시기에는 수목의 생육의 둔화와 기온 하강으로 인하여 토양수분 감쇄현상 및 변화가 적게 나타나 토양수분의 변화양상이 계절마다 다르게 나타난다. 이에 토양수분의 감쇄현상을 파악하면 곧 산림지역에서의 증발산량 및 토양수분 소비특성을 파악할 수 있기 때문에, 산림에서 실제 토양수분 모니터링과 이를 통한 시간별, 깊이별 토양수분 변화 및 감쇄현상을 파악하는 것은 중요하다. 따라서 본 연구에서는 침엽수 산림에서의 토층별 월별 토양수분의 감쇄특성을 분석하기 위하여 침엽수림에서 토양수분 장기 모니터링 시스템을 구축하여 시간별, 토층별 토양수분 모니터링을 실시하고, 이를 바탕으로 침엽수림에서의 토양수분 감쇄현상을 분석하였다. 또한 토양수분 데이터 및 기상자료를 활용하여 월별, 기간별 토양수분 감쇄곡선을 산정하고 감쇄상수를 비교하였으며, 감쇄특성에 대하여 비교 분석하였다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.53-60
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• 2022

Recently, Black soybean (Glycine max L. Merr.) is being cultivated in paddy fields instead of rice. However, research related to the effective sowing date is insufficient in paddy fields. This study aimed to identify the sowing date for stable cultivation of black soybean by investigating its yield and seed characteristics in a paddy field. In the study, cultivation experiment with five different sowing dates (May 25, June 10, June 25, July 10, July 25) were conducted in 2019 and 2020. Days from sowing to flowering can be shortened by delaying the sowing date. In the present study, the yield of black soybean in paddy fields was the highest with June 10 as the sowing date and was calculated as 224 kg·10a^-1 and 200 kg·10a^-1 in 2019 and 2020, respectively. However, the highest values of seed coat cracking was 51.1±5.1% and that of total anthocyanin contents was the 3.99±0.72 mg/g, both of which were observed in 2020 for the experiment with May 25 as the sowing date. Regression analysis showed a positive correlation (R²=0.9312) between soil water contents and seed coat cracking rate during the flowering period. Hence, the soil water contents during the flowering period would have a negative effect on the seed coat development.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.3
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• pp.247-253
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• 1982

This experiment was conducted to find out the optimum date for Combine harvesting of barley in the double cropping paddy field. By the consideration of moisture contents of grain, grain loss, rate of unhulled grain, and discoloring of external plant parts, the optimum date for harvesting was observed to be about 41 days after heading under natural condition. On the other hand, when desiccant was applied on the 34 days after heading, it could be shortened natural harvesting time for 3 days without any yield loss and grain qualities, too.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.250-257
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• 1997

Stem diameter and shoot fresh weight of tomato grown in greenhouse were measured non-destructively at 10 minutes interval from 1 to 16 July, 1996 with displacement detector using strain gauges and with suspension-type load cell, respectively, and simultaneously were measured soil water potential, transpiration and solar radiation. Ample water was irrigated before experiment, and thereafter, irrigations were made on the next morning when visual symptoms of wilting appeared. Shoot fresh weight and stem diameter showed very similar patterns in diurnal changes which are characterized by predawn maximum and afternoon minimum and in long- term evolutions, suggesting that stem diameter shrinkage and expansion are closely related to plant water content and growth, respectively, Shoot weight and stem diameter reached minimum values a little later than the time on which transpiration showed maximum. The daily net gains of fresh weight(DG) and stem diameter(DI) showed significantly Positive correlations with solar radiation in those days on which plants were not water-stressed. However, Dl and DG on those days of water stress showed much lower values than expected from the relationships between solar radiation and them. Transpiration was much lower than the expected potential transpiration on 10 July, implying that plants were water-stressed. In this case water stress was not detected from visual symptom of wilting and/or soil water potential, but was able to be identified by the lower DI and DG than the expected. The maximum contraction of stem diameter(MC) and the maximum loss of fresh weight(ML) during daytime showed significantly positive correlations with solar radiation in those days on which plants were not water-stressed and were observed greater than expected from the relationships on severely water-stressed days. But mild water stress could not be discernable by ML and MC. It would be concluded that the daily net gains of fresh weight and/or stem diameter could be used as criteria for diagnosing the water status of tomato and for triggoring the onset of irrigation in automatic system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.281-285
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• 1976

An investigation on the breeding time of the Mangrove oyster, Crassostrea rhizaphorae, in the lagoon of Cocineta which is located in the northwestern part of Venezuela was carried out from February through May in 1976. Surface water temperature was high, over $25^{\circ}C$ and specific gravity was around 1.0258. Transparency to water depth varied between 29 and $80\%$. The range of water content of the oysters increased from February through May. However, the averge monthly range of water content varied only slightly from 80.67 to $82.25\%$. From the numbers of matured planktonic larvae together with total numbers of planktonic larvae found, we may assume that the best seedling period is from late April through early May. We may also assume that the best area is around stations 4 and 3, station 3 being slightly better than station 4.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1997.05a
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• pp.5-10
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• 1997

본 실험은 온실멜론을 암면재배하여 수분전후 21일간 질소공급제한이 생육, 품질 및 양분흡수에 미치는 영향을 조사하였다 가을과 겨울재배에서는 상당히 고농도의 양분을 흡수하는 시기이기 때문에 시즈오카대 처방(NO$_3$-N = 8me/$\ell$)을 이용하여 재배하고 양분도 제한했기 때문에 식물체는 양분부족 현상을 야기하였다. 교배 후 양분흡수를 제한하는 경우 상위엽의 과잉비대를 방지하였으나 초장과 과실의 생체증은 양분공급을 제한하지 않는 경우에 크게 나타났다. 그 원인은 양분공급을 제한하는 기간 및 시기와 시용배양액 농도 차이에 따른 양분흡수량의 차이라고 생각되었다. 이상으로부터 수분기에는 양분흡수량이 많기 때문에 양분공급을 제한하지 않고 양분공급을 증가시키는 편이 과실의 외관, 품질향상 및 과실의 당도향상에 상당히 기여할 것으로 생각되었다.