• 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.

• Journal of agriculture & life science
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• v.45 no.1
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• pp.49-58
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• 2011

Characteristics of leaf unfolding and flowering of 31 chestnut varieties cultivated in southern Korea was conducted to provide basic data for chestnut varieties improvement. There were slight differences among varieties in leaf unfolding time and leaf unfolding was late in 2010 compared to 2008 and 2009. Leaf unlolding took about 8 days to complete in 2008 and 2009, but that took about two weeks to complete in 2010. In 2008 and 2009, flowering beginning and flowering end of staminate flower occurred in early May and June, those were detained by low temperature of April in 2010. Although pistallte flower in flowering characteristics showed very similar to flowering period of staminate flower, The flowering beginning for pistillate flower was earlier approximately 20 days than for staminate flower.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.6
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• pp.841-848
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• 1997

This study was conducted to investigate the inflorescence habit mainly on major in farmer's peanut cultivar of the Shinpung plant type "Daekwang" of sequential branching and the Virginia plant type "Daepung" of alternate branching until maximum flowering dates. All flowers of two pairs of opposite branch in "Daekwang" showed almost symmetrical flowering order and in "Daepung" also showed similar tendency though it had somewhat irregalar alternate branching type in opposite branches. The lowest node in each branch had seven flowers while upper nodes had less flowers in this period. The first flower in "Daekwang" was born at first node of second branch of cotyledonary branches compared to those of "Daepung" at first reproductive branch of cotyledonary branches. One pair of cotyledonary branches had two-thirds of total flowers in two cultivars. Dates of average flower proceeding between nodes in each branch of "Daekwang" were appeared 4.32 days in main axil, 1st and 2nd opposite primary branches were 4.44 and 5.13 days, and 1st and 2nd secondary branches were 5.81 and 6.41 days respectively, but "Daepung" showed similar flower proceeding dates in all branches. but "Daepung" showed similar flower proceeding dates in all branches.

• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.305-309
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• 2013

A freesia (Freesia hybrida Hort.) 'Dancing Flame' was developed for the cut flower in the National Institute of Horticultural Herbal Science in 2007. This hybrid was selected from a crossing between a seedling 'Vulcano' and 'Sailor', which is scarlet double flowering and purple single flowering, respectively, and 'Figaro' which is bright red color and semi-double flowering, in 2000. Morphological characteristics of the selected hybrid were investigated for 3 years from 2005 to 2007, and then it was named 'Dancing Flame'. 'Dancing Flame' had red color (RHS R44B) and single flower with yellow center color (RHS Y9A). The growth of the plant was vigorous and the average height was 93.3 cm. The average flower width was 60 mm, number of floret per stalk was 14.3, and stalk was 13.2 cm length. The average yield, 7.8 cuttings per plant, was 2.5 stems per plant more than the control cultivar. The average days to first flowering of 'Dancing Flame', 133 days, was approximately 5 days earlier than the control cultivar. And its average yield, 7.1 cormlet per plant, was also 2.5times more than the control cultivar.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.5
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• pp.374-378
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• 2002

To evaluate growth habits, fresh pod yield potential, and possibility of early and late seeding, seeding dates were extended from March 21 to June 20 by PE mulching and non-mulching. Soil temperature, under 5cm from surface, above 15$^{\circ}C$ at 10 a.m. in early seeding reached about March 25 in mulching and April 5 to April 12 in non-mulching. Days to emergence and first flowering were accelerated owing to increasing temperature, as seeding was delayed. Days to emergence according to seeding dates reduced 21 to 8 day in mulching and 33 to 10 day in non-mulching. Days to flowering were ranged from 51 to 26 day in mulching and from 69 to 32 day in non-mulching and differences between mulching and non-mulching on each seeding date had 18 to 4 days. Early seedings till April 21 had 160-170 flowers per plant for 8 weeks, while late seedings from May 21 increased more speedily with 200 flower for 6 weeks. Harvesting of fresh peanut, at 80 days after first flowering, was possible from Aug. 1 to Oct. 7 (133-108 days to harvest) by mulching and from Aug. 19 to Oct. 12 (151 to 114 days) by non-mulching. Yields between mulching and non-mulching in early seeding until April 21 had more difference, but in late seeding after May 21 was higher and showed insignificance. Pod setting periods by early and late seeding were about 3 weeks equally. In late seeding pod setting were almost concentrated for front 15 days. In spite of difference of fresh pod weight between two seeding times, the distributions of average of seed weight showed nearly same tendency.

• 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.

• Atmosphere
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• v.25 no.4
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• pp.693-706
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• 2015

A shift of first fowering date (FFD) of spring blossoms (cherry, peach and pear) over the northest Asia under global warming is investiaged using dynamically downscaled daily temperature data with 12.5 km resolution. For the study, we obatained gridded daily data with Historical (1981~2010), and Representative Concentration Pathway (RCP) (2021~2100) 4.5 and 8.5 scenarios which were produced by WRFv3.4 in conjunction with HadGEM2-AO. A change on FFDs in 21st century is estimated by applying daily outputs of WRFv3.4 to DTS phonological model. Prior to projection on future climate, the performances of both WRFv3.4 and DTS models are evaluated using spatial distribution of climatology and SCR diagram (Normalized standard deviation-Pattern correlation coefficient-Root mean square difference). According to the result, WRFv3.4 and DTS models well simulated a feature of the terrain following characteristics and a general pattern of observation with a marigin of $1.4^{\circ}C$ and 5~6 days. The analysis reveals a projected advance in FFDs of cherry, peach and pear over the northeast Asia by 2100 of 15.4 days (9.4 days). 16.9 days (10.4 days) and 15.2 days (9.5 days), respectively, compared to the Historical simulation due to a increasing early spring (Februrary to April) temperature of about $4.9^{\circ}C$ ($2.9^{\circ}C$) under the RCP 8.5 (RCP 4.5) scenarios. This indicates that the current flowering of the cherry, peach and pear over analysis area in middle or end of April is expected to start blooming in early or middle of April, at the end of this century. The present study shows the dynamically downscaled daily data with high-resolution is helpeful in offering various useful information to end-users as well as in understanding regional climate change.

• Journal of the Korean Society of Tobacco Science
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• v.11 no.2
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• pp.157-179
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• 1989

This Study was conducted to estimate the degree of dominance and gene frequency of some sueful characters in tobacco. The eight parents and a set of 28 crosses of F'1s was F'2s were used as materials, and planted on oriental's and burley cultivated system as randomized block designs, respectively. The observed characters were six agronomic characters which were plant height, number of leaves per plant, leaf length, leaf width, days to flowering and yield, and the data obtained from the experiment were analyzed from methods by Hayman's and Jinks. The results obtained are summarized as follows: 1. In Vr-Wr graphical analysis, number of leaves per plant, leaf length, days to flowering and yield were found to be inherited in partial dominance, and plant height was over dominance to be similar to complete dominance, but leaf width was inherited with partial dominance close to complete dominance. 2. In the gene frequency, two varieties Xanthi-Basma and KA 102, for days to flowering and yield had larger number of dominant genes as those were situated near the point of origen. 3. Additive effects of genes(D) were greater than dominance effects of Genes(H) for six agronomic characters except plant height, and mean degree of dominance over all loci was lower than 1 for days to flowering yield, leaf length and number of leaves per plant.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.895-898
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• 2010

A new light pink spray-mum, 'Noble ND' was bred by crossing 'Mona Lisa', a white anemone type flower, and 'Dark Weldon', a pink anemone type flower in October, 2004. The growth and flowering characteristics were investigated in forcing, natural, and retarding cultures from 2006 to 2007. The 'Noble ND' was a medium-flowering fall-mum with light pink anemone type flower and had 9.2 flowers per stem, with 4.8 cm flower diameter in natural culture. The number of days to flowering and flowers per plant was 57 and 7.4, respectively, in forcing culture of 'Noble ND', whereas the number of days to flowering was 48 in retarding culture.

• FLOWER RESEARCH JOURNAL
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• v.18 no.1
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• pp.73-76
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• 2010

A new light pink spray-mum, 'Brown ND' was bred by crossing between 'Noeul', a yellow anemone type flower, and 'Dalma', a pink anemone type flower in October 2003. The growth and flowering characteristics were investigated in forcing, natural, and retarding cultures from 2005 to 2007. The 'Brown ND' was a medium-flowering fall-mum with light pink anemone type flower and had 10.6 flowers per stem, 4.1 cm diameter of flower in natural culture. The number of days to flowering and flowers per plant was 59 and 9.1, respectively, in forcing culture of 'Brown ND' whereas the number of days to flowering was 49 in retarding culture.