• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.1
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• pp.23-30
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• 1993

This study was conducted to obtain the fundamental information on antioxidant component as affected by process of grain filling in different plant types of sesame. Sesamin and sesamolin as antioxidant components, oil content and seed weight were investigated for two plant types with different by branching habit. The sesamin and sesamolin contents in grains followed a pattern of increase immediately after flowering in branch type and monocapsule habit than non-branch type and tricapsule habit. But they started to decrease around 45 days after flowering, which oil content and seed weight continued to increase until maturity. The sesamin content increased quickly up from 10th to 40th day after flowering and showed almost maximum at 43th day after flowering. The sesamolin content increased quickly up from 20th to 30th day after flowering and showed almost maximum at 45th day after flowering. The oil content increased quickly up from 20th to 30th day after flowering and showed almost maximum at 47th day after flowering. The seed weight increased quickly up from 20th to 40th day after flowering and showed almost maximum at 48th day. The sesamin content, sesamolin content, oil content and seed weight showed almost maximum at from 43th to 48th day after flowering. So that this period was considered to be of physiological maturity.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.297-303
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• 2013

This study was carried out to examine the effect of Red LED (660 nm) and fluorescent lamp for night break (NB) treatments of each 3 hours (22:30-01:30), 4 hours (22:00-02:00) and 5 hours (21:30-:02:30) per day for 53 days on flower bud initiation and growth in Chrysanthemum cv. 'Baekma' and cv. 'Jinba'. The days to flower budding after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (21.0 days) and 5 hr (20.5 days) NB, and it was shorter at Red LED 3 hr (14.2 days). The days to flowering after short-day treatment in 'Baekma' was longer at fluorescent lamp 4 hr (54.0 days), 5 hr (53.5 days) NB, and Red LED 5 hr (53.3 days), and it was shortest at Red LED 3 hr (50.2 days) NB treatment among all treatments. The days to flower budding after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (20.6 days) and was shorter at Red LED 3 hr (14.1 days) among all treatments. Similarly, the days to flowering after short-day treatment of 'Jinba' was longer at fluorescent lamp 4 hr (55.3 days) and was shortest at Red LED 3 hr (50.2 days) among all treatments. Therefore, inhibition of flower bud initiation was the most effective under fluorescent lamp 4 hr treatment. The length of cut flower of 'Baekma' was increased by fluorescent lamp 4 hr, 5 hr, and Red LED 5 hr, but of 'Jinba' was longer at LED 4 hr and 5 hr treatment. The weight of cut flower of 'Baekma' was heaviest at fluorescent lamp 5 hr treatment and was at Red LED 5hr treatment for 'Jinba' even though there was not statistically significant difference between 'Baekma' and 'Jinba'. Consequently, under fluorescent lamp 4 hr for night break was the most effective on flower bud initiation, flowering inhibition and cut-flower characteristics in 'Baekma' and 'Jinba'.

• Journal of The Korean Society of Grassland and Forage Science
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• v.21 no.1
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• pp.1-6
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• 2001

This experiment was conducted to evaluated the effect of maturity at harvest on the changes in quality of round baled rye silage at forage experimental field of Grassland and Forage Crops Division, National Livestock Research Institute, RDA, Suwon in 1998. The experimental design was a split-plot design with three replications. The main plots were three different harvest stages : boot, heading and flowering stages, and the subplots were days after ensiling : 1, 2, 3, 5, 10, 30, 45, and 60 days. The wilting period of boot, heading and flowering stages were 1, 0.5 and 0.5 days, respectively. The final pH of rye silage was higher in the order of flowering, boot and heading stages. And pH of flowering stage began to change at early fermentation period, but that of boot and heading stages was delayed 1~2 days. Ammonia-N content of boot stage was highest. and that was increased as fermentation progressed. But Ammonia-N of heading stage was decreased to 30 days. then that was increased after 45 days fermentation. Among fermentation periods, inside temperature of deep place was not affected by external temperature. And that of deep place was increased to 3$0^{\circ}C$ at early fermentation. then decreased as fermentation progressed. However surface temperature was affected by external temperature after 10 days. Acetic acid content was not changed with 5 days by harvest stages, but that of boot stage was increased after 10 days. Butyric acid of boot stage was increased after 5 days. but that of heading stage was increased after 10 days. However lactic acid was increased from 1~2% to 6~8%. Lactic acid bacteria (LAB) of heading and flowering stages were highest at 5 days fermentation, and that of boot stage was highest at 10 days fermentation. The results of this study indicate that fermentation of round baled rye silage occur within 5 days. Therefore, any modification should be applied with an 5 days for high quality of round baled rye silage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.2
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• pp.165-173
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• 1985

The objectives of the study were to investigate the effects of foliage clipping on photosynthesis and grain filling for branch and non branch types under the polyethylene film mulch and non mulch conditions in mono cropping and second cropping after barley in sesame (Sesamum indicum L.), and to improve poor grain filling at later flowering time utilizing these data. One thousand grain weight was more decreased in branch type than in non branch type, in polyethylene film mulch condition than in non mulch condition, and in second cropping after barley than in mono cropping by clipping lower part foliage. Twentyfive percent clipping of lower part foliage showed a little increase than no clipping. Matured grain rate also showed same tendency between branch and non branch type and between mono cropping and second cropping after barley as well as 1,000 grain weight except for polyethylene film mulch. Matured grain rate of 25% foliage clipping at 30 days after flowering in non branch type presented a little increase but decreased in branch type. Clipping of higher part leaves were so serious decrease of matured grain rate that higher part leaves at late maturing time have a major role in photosynthesis. Matured grain rate of foliage clipping at 10 days after flowering was decreased in all treatments. Chlorophyll content of higher part leaves at 50% lower part foliage clipping presented 39% increase compared to same positioned leaves of non treatment, and 66% increase by 50% higher part foliage clipping in lower part leaves. Photosynthetic activity was 58% more increased in 50% lower part foliage clipping than no clipping, but seriously decreased in 50% higher part foliage clipping. Therfore, photosynthates of remained lower part leaves could not only support their own demands, but also any contribution to translocation of photosynthates from source to sink at late maturing time. Harvest index was 28% increased in 25% lower part foliage clipping and 13% decreased in 50% higher part foliage clipping compared to no clipping. Leaf area was 48% increased in 50% lower part foliage clipping compared to the same positioned leaves of no clipping, and only 5% increased in higher part foliage clipping. Productivity by foliage clipping compared to non treatment, was highly decreased in branch type than in non branch type, in second cropping after barley than in mono cropping. Little difference was detected between polyethylene film mulch and non mulch conditions. Twenty five percentage of lower part foliage clipping on mono cropping of non branch type appeared 5% and 8% yield increase in each of polyethylene film mulch and non mulch conditions compared to no clipping, and all decreased in other treatments. Mean loss of productivity by foliage clipping at 10 days after flowering was serious than clipping at 30 days after flowering. As the result, contribution to photosynthesis of source at 10 days after flowering are larger than that at 30 days after flowering in sesame. Fifty percent lower part foliage clipping at 10 days after flowering showed so the most serious yield decrease that lower part leaves at that time were considered as the main role leaves for photosynthesis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.61-69
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• 2024

Considering the threats of climate change, this study was conducted to investigate the influence of temperature and day-length on soybean growth and yield when sown late in comparison to the optimal sowing time in the southern region of the Korean Peninsula. Sowing was executed in 10-day intervals, including on July 1, 10, 20 and 30 and August 10, considering that the optimum sowing time of the three soybean varieties with different ecotypes is June 20. Emergence rates did not differ significantly between late-sowing and optimal sowing in all ecotypes; however, the number of days to emergence, flowering, and maturity was smaller after late sowing. A multiple-regression approach was used to test the effect of temperature and day length on the number of growing days after late sowing compared to the optimal sowing time. This analysis revealed that the number of days required from sowing to flowering was positively correlated with both day length and temperature, and the number of days from flowering to harvest was positively correlated with day length and negatively with temperature. A multiple regression equation can be calculated as follows: the number of days required from sowing to flowering (Y) = 3.177 + (0.030 × (sum of day length + sum of temperature)), and the number of days required from flowering to maturity (Y) = 20.945 + (0.021 × (sum of day length + sum of temperature)). Multiple growth parameters were significantly correlated with yield components, depending on growing days. Optimal sowing resulted in the best yield, while later sowing decreased yield compared to optimal sowing. To avoid a significant decrease in yield, early-maturing species should be sown by July 20, while late-maturing species should be sown by July 10.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.247-250
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• 1998

This study was carried out to investigate the effects of changes of ionic strength according to growth stage on growth and flowering of Dendranthema grandiflorum (Ramat.) Kitamura 'Seiun' grown hydroponically in perlite. The stage I, II, and III covered early vegetative growth (27-40 days after planting), latter vegetative growth (41-54 days), and reproductive growth (55-80 days), respectively. The 2 strength (1S and 2S) of nutrient solution were treated in stage I, whereas 3 strengths (1S, 1-2S, and 2S) were treated in stage II. Then, total 9 treatments in stage III were designated by 3 treatments (tap water, 1S, and 2S) for each 3 strengths in stage II. Each nutrient solution was applied 8 times per day. At vegetative growth stage (54 days after planting), stem length was highest when irrigated 8 times a day with 1S nutrient solution. Both photosynthesis and transpiration rate were higher in 1S than those in other treatments (1-2S, 2S), whereas leaf chlorophyll content was highest in 2S treatment. Ion content of plant treated with 2S was higher than other treatments. Growth (plant height, leaf area, stem length), fresh weight, and dry weight of each plant organ after flower bud formation were better in tap water treatment (1-1-0) than other 1S treatments (1-1-1, 1-1-2). Regarding the number of days to flowering, tap water treatment was the most effective. Thus, after flower bud formation supplying tap water or lower concentration of nutrient solution than those used during the vegetative growth stage was economical in saving chemical fertilizers, shortening the number of days to flowering, reducing salt accumulation in media, saving efforts of leaching, and reducing ground water contamination.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.363-369
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• 2007

The objective of this study was to investigate the variation of Chinese milk vetch(Astragalus sinicus L.; CMV) seed quality after flowering. We tagged individual open flowers of CMV at the day of maximum flowering(11 May) in Seoul, Korea. Seed samples were harvested serially at 15, 20, 25 and 30 days after flowering(DAF). To compare with dried seeds, non-dried seeds were tested immediately after harvest and the remaining seeds were placed at room temperature for 4 weeks. Seed length, 1000 seed weight, moisture content, germination rate(GR), mean germination time(MGT), germination speed(GS), germination performance index(GPI) and physical dormancy rate(PDR) were investigated. Seed length increased to 2.6 mm and 1000 seed weight reached up to 2.2 g until 25 DAF. Seed moisture content dramatically decreased from 20 to 25 DAF. Moisture content of non-dried seed(7.5%) was similar to that of dried seed(5.5%) at 25 DAF. The rate of seed viability reached up to 94% at 25 DAF. In case of dried seed, GR increased up to 39% at 25 DAF whereas GR of non-dried seed varied from 5 to 10%. GS and GPI of dried seed were significantly higher than those of non-dried seed since 25 DAF. PDR of dried seed has decreased since 20 DAF, whereas PDR of non-dried seed has increased. GR, GS and GPI increased as PDR decreased. Our results evidenced that PDR might be one of major factor in variation of seed quality, of which development was completed at 25 DAF.

• Current Research on Agriculture and Life Sciences
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• v.9
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• pp.147-155
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• 1991

Effects of harvest date, number of the leaves remained on stump after flower cutting, duration of cold treatment on the growth and flowering of L. elegans 'Connecticut King' bulb were tested. Shoot emerging rate increased over 90% by delayed cold treatment, late harvesting time and more leaves remained. Flowering rate increased over 90% when conducted cold treatment of 90 days to the premature bulb at flowering date, the bulb matured for 50 days with 10 leaves and the bulb matured for over 30 days with 20 leaves, and when conducted cold treatment of 50 days to the bulb matured for over 30 days with all leaves. Delayed cold treatment duration shortened days needed to shoot emergence and flowering. Especially days to flower of the premature bulb at flowering date were the shortest of all treatments, and can be flowered within 100 days after planting. In generally, plant height, number of flowers per plant and stem diameter generally increased by longer bulb maturing period after flower cuting, and the premature bulb harvested at flowering date showed poor growing and flowering responses. But, if used the larger size bulb, it is believed that the prematured bulb can be forced to flower normally in current year without bulb maturing period.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.2
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• pp.68-76
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• 2006

A thermal time-based two-step phenological model was used to project flowering dates of Japanese cherry in South Korea from 1941 to 2100. The model consists of two sequential periods: the rest period described by chilling requirement and the forcing period described by heating requirement. Daily maximum and minimum temperature are used to calculate daily chill units until a pre-determined chilling requirement for rest release is met. After the projected rest release date, daily heat units (growing degree days) are accumulated until a pre-determined heating requirement for flowering is achieved. Model calculations using daily temperature data at 18 synoptic stations during 1955-2004 were compared with the observed blooming dates and resulted in 3.9 days mean absolute error, 5.1 days root mean squared error, and a correlation coefficient of 0.86. Considering that the phonology observation has never been fully standardized in Korea, this result seems reasonable. Gridded data sets of daily maximum and minimum temperature with a 270 m grid spacing were prepared for the climatological years 1941-1970 and 1971-2000 from observations at 56 synoptic stations by using a spatial interpolation scheme for correcting urban heat island effect as well as elevation effect. A 25km-resolution temperature data set covering the Korean Peninsula, prepared by the Meteorological Research Institute of Korea Meteorological Administration under the condition of Inter-governmental Panel on Climate Change-Special Report on Emission Scenarios A2, was converted to 270 m gridded data for the climatological years 2011-2040, 2041-2070 and 2071-2100. The model was run by the gridded daily maximum and minimum temperature data sets, each representing a climatological normal year for 1941-1970, 1971-2000, 2011-2040, 2041-2070, and 2071-2100. According to the model calculation, the spatially averaged flowering date for the 1971-2000 normal is shorter than that for 1941-1970 by 5.2 days. Compared with the current normal (1971-2000), flowering of Japanese cherry is expected to be earlier by 9, 21, and 29 days in the future normal years 2011-2040, 2041-2070, and 2071-2100, respectively. Southern coastal areas might experience springs with incomplete or even no Japanese cherry flowering caused by insufficient chilling for breaking bud dormancy.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.4
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• pp.269-274
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• 1994

An experiment was carried out to investigate the effects of irrigation period on the yield and quality of melon (Cucumis melo L.) cultivated in green house 1992~1993. Four different irrigation period was applied ; from transplanting to harvest(Irrigation I), from initial flowering to 35 days after flowering(Irrigation II), from initial flowering to 20 days after flowering(Irrigation III), from initial flowering to 5 days after flowering(Irrigation IV). The water was applied by drip irrigation when the soil water potential of 15cm depth reach at -0.5bar. The results obtained were as follows ; 1. The amount of water applied during the periods were 170.5mm, 145.0mm,126.9mm and 78.8mm for irrigation period I, II, III and IV, respectively. 2. Average evapotranspiration during the cultivation of melon was 3.31mm/day. Evapotranspiration was the highest at the period from 5days after flowering to 15days after flowering. 3. The total yield was increased with the higer amount of water applied, and the yield was in the order of Irrigation I, II, III and IV. However, the yield with economically high quality was the highest in Irrigation III. 4. The sugar content and quality of Net form were decreased with higher irrigation amount.