• Journal of Ecology and Environment
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• v.31 no.2
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• pp.139-146
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• 2008

To clarify the relationship between the timing and the duration of flowering among populations, plants, and individual flowers, the dates of flower budding, flowering and deflowering were monitored for ten woody species from March 1 to June 30, in 2005, 2006 and 2007, in temperate deciduous forests at three sites of Namsan, and individual plants from seven woody species were monitored from March 1 to May 31, in 2006. Total durations of flower budding, flowering, and deflowering varied among the plant species. Three durations of these phenological stages of Stephanandra incisa were the longest (74 days, 109 days, and 101 days, respectively), and those of Prunus serrulata var. spontanea were the shortest (7 days, 7 days, and 4 days, respectively). For each species, phenological durations varied among years but were similar among the study sites in the same year. There was no relationship between flowering time and flowering duration on the population level. On the plant level, the duration of flower budding was over 11 days in all specie; S. incisa had the longest duration (73.3 days), and that of Styrax japonica was long as well (29.0 days), while that of Prunus leveilleana was the shortest (11.3 days). The longer the mean flower budding duration, the greater the difference among the plants within a species. The flowering duration of for S. incisa was 92.2 days, while that of Forsythia koreana was 27.2 days. The flowering durations of all other species were $10{\sim}20$ days. The deflowering duration was 92.0 days in S. incisa and <15 days in all other species. Differences among the plants in deflowering duration were smaller than those of the other phenological stages. In the species that flowered in April, the correlation coefficient between the flowering duration and the first flowering date was negative and significant. However, in the species that flowered in May, the correlation between flowering duration and the first flowering date was not significant. For individual plants of all species except for S. alnifolia, the earlier the flowering time, the longer the flowering duration. Differences between flowering time and flowering duration across years were significant in six species.

• Journal of Ecology and Environment
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• v.37 no.4
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• pp.155-163
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• 2014

Adonis multiflora is a spring ephemeral herb growing in temperate deciduous forests. To determine the flowering properties of a natural population of A. multiflora, air temperature, flowering time, and flower-falling were monitored from February 2009 to May 2011. The A. multiflora population in this study started flowering in early March and ended it in mid-April. The average flowering duration of a flower was 14.4 days in 2009 and 19.6 days in 2011. The average duration of flower-falling was between 3.4 days and 4.2 days for three years. Cumulative flowering rate (CFR) was correlated with year day (YD), year day index (YDI), and Nuttonson's index (Tn), with correlation coefficients (CC) of over 0.9 at the 1% significance level; CC value between CFR and YD was the largest and that between CFR and YDI was the smallest. However, at the 5% significance level, CFR was closely related with Tn more than any other factors. The CCs between flowering times of two years in each plant were high and significant at 1% level. The YD value of flowering time of a flower was inversely related to its flowering duration significantly for three years. In a given plant, when more flowering started early, the flowering duration was longer. The first flower blossomed on 73.4 YD in 2010 and 78.9 YD in 2011, and remained for 16.7 days in 2009 and 27.4 days in 2011, respectively; the fifth flower developed on 92.5 YD in 2010 and 96.6 YD in 2011, and remained for 8.0 days in 2009 and 14.6 days in 2011. The YD differences between the flowering times of two flowers decreased in the order of inflorescence.

• FLOWER RESEARCH JOURNAL
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• v.26 no.4
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• pp.179-186
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• 2018

Ranunculus asiaticus characterizes colorful and attractive flower shapes that are related with the ornamental value of bulbous plants. Improving ornamental value of bulbous flowers has been the general goal of floricultural market. Gibberellic acid ($GA_3$) and benzyladenine (BA) play an important role in growth and developmental processes in floriculture. Combinational treatments of these two hormones have been used in floriculture to improve flower quality. We assessed the effects of combined $GA_3$ and BA, as well as the individual effects of each hormone, on growth characteristics using soil drench application to eight R. asiaticus cultivars, 'Giallo Millepetali', 'Bianco Millepetali', 'Arancio Millepetali', 'Rosa SC', 'Arancio Pratolino', 'Giallo Pratolino', 'Bianco Pratolino', and 'Rosa Ch Pratolino'. $GA_3$ treatments increased plant height and first flower size of R. asiaticus cultivars. Moreover, about 5 to 9 days to flowering were averagely shortened by $GA_3$ treatments compared to controls. On the other hand, the opposites, including first flower size and days to flowering, were observed for cultivars treated with BA, compared with controls. Treatments of $GA_3$ + BA generally affected growth traits, such as plant height, flower size, and the timing of flowering on some R. asiaticus cultivars. In particular, about 5 to 6 days to flowering were reduced on average by Treatments of $GA_3$ + BA. Our results showed positive growth effects, including plant height, days to flowering, first flower height, number of flowers from the application of individual and combined hormones to R. asiaticus cultivars and demonstrate a role for these hormones in future bulbous floriculture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.5
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• pp.461-467
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• 1992

A mungbean cultivar, 'Seonhwanogdu', was seeded on April 20, May 10, June 1, June 20, July 10 and July 30 in 1988, 1989 and 1990 to determine the optimum seeding date of mungbean in Cheju province. As seeding was delayed from April 20 to June 20, the number of days from emergence to first flowering (days to flowering) decreased from 56.7 to 36.7 days, on the three year average. Days to flowering of mungbean seeded on July 10 and 30 ranged 30 to 35 days except that of the plants seeded on July 10, 1988. Days to flowering linearly decreased as the average of daily mean air temperature from emergence to the first flowering increased. The number of days from the first flowering to the first maturity (days to maturity) in mungbean seeded on April 20 to July 10 ranged 14 to 21 days and was 29 to 40 days at the July 30 seeding. The number of pods per plant, the number of seeds per pod, 1000 seed weight and yield tended to increase with delaying seeding up to June 1 and June 20, and then to decrease with further delaying seeding. This study indicates that the optimum seeding time of mungbean in Cheju province is around mid-June.

• FLOWER RESEARCH JOURNAL
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• v.16 no.4
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• pp.247-254
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• 2008

This study was conducted to investigate effect of temperature, photoperiod, and plant growth regulators on the growth and flowering of Dendrobium phalaenopsis. Photoperiod treatments of 10 or 16 day length were from Mar. 24 to May 23. After treatments, all plants were exposed under natural photoperiod. Temperature treatments promoted development of new shoots (leads) of Dendrobium phalaenopsis 'Semi Alba' at $30/25^{\circ}C$(day/night) for 12 weeks, and 16 hr-photoperiod treatment promoted development of new shoots and flowering. The 16 hr photoperiod Dendrobium phalaenopsis 'Candistraipe ${\times}$ Tedtakiguz' no difference in the numbers of flower, flower width, and stalk length compared to the 10 hr photoperiod. Days to first flowering from appearance of new shoot were 241 days under natural photoperiod, 243 days under 10 hr, and 216 days under 16 hr, so that 16 hr-photoperiod treatment was faster about 25 days than that of natural or 10 hr treatment. There was not significant difference in growing and flowering of Dendrobium phalaenopsis among plant growth regulators.

• The Korean Journal of Ecology
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• v.1 no.1
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• pp.17-23
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• 1977

Flowering dates of 389 plant species in the Hongneung Arboretum, Seoul, had been recorded from 1968 through 1975. The thermal analysis on the air temperature as the key factor determining the first flowering date, with climatological data obtained in the Arboretum, were undertaken by Nuttonson's Index (1948) and Lindsey & Newman's Index (1956). The results and conclusion in this study are as follow; Peak in the bell shape distribution curve of the species and first flowering dates, largely, was early May. Flower spans of most species were 10 to 20 days, neverthless, some species flower only a few days while others may stay flowering a hundred days even more. Increase-curves of summation temperature from early spring through late-summer showed almost the same mode in both Nuttonson;s Index (Tn) and Lindsey & Newman's Index (T1). These Indices manifested the exponential curve, increasing slowly at the beginning of spring chiefly but rapidly from the middle part of April. The equation of the linear relationahip between Tn and Tl as far as in thisstudy is as follow. Tl=230Tn It appears that the distribution of summation temperature, below Tn=400°C·day, affects the first flowering, even though it could be modified somehow by the distribution of precipitation, day length and others. Nuttonson's Index (Tn.f) and Lindsey & Newman's Index (Tl.f) upon the thermal amount first flowering dates have been respectively simulated as follow. Tn.f=θa + C Tl.f=230θa + 230C where θ is air temperature 10°C, a and C are a constant.

• 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 CROP SCIENCE
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• v.47 no.6
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• pp.437-442
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• 2002

To breed high quality and yield peanut variety according to select the short flowering duration, fifteen germplasms (1 virginia,7 spanish,6 valencia types and var, Daekwang) were investigated the flowering habit and agronomic characteristics from 1998 to 1999. Emergence date of the selected short flowering duration germplasms (SPFGs) was earlier 1-3 days and middle or small seed than that of var, Daekwang. Main stem length was longer 57cm but the number of branches, pods, 100-seed weight, and pod weight per plant was reduced 25%, 23%, 42%, 46%, respectively, in SPFCs comparing to var, Daekwang. The flowering date in SPFGs was similar but the flowering duration was earlier 5-16 days than that of var, Daekwang (52 days). Varieties that flowered shorter duration than 50 days were 18.8% among the SPFGs. The number of total flowers in SPFGs was fewer 50% than that of var, Daekwang. The rate of flowering inhibition were 50-52% than that of var Daekwang. The frequencies of flowering duration (under 50 days) were 7.7% in virginia, 46.2% in spanish, 53.9% in valencia. The effect of shading treatment on rate of flowering inhibition were 11%, but number of branches and pods were reduced by 27-31% in valencia type compared to non-shade. Correlation coefficient was significant positively ($r=0.9314^*$ virginia, $r=0.9551^*$ spanish, $r=0.9551^*$ valencia) between the air temperature and flower number, The frequency of peg and pod number on 1st to 2nd nodes in SPFGs were more 3-12%, 21-26% than that of var. Daekwang. The rate of mature pods at 80 days after flowering were higher 12-17% than that of var, Daekwang (68%). Correlation coefficient was high significant negatively between date of first flower and flowering date, the ratio of mature pod.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.64-67
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• 2001

Snap bean is a new corp in Korea but believed to have a great deal of potentials for both domestic and overseas markets. The present study was performed to obtain the basic information about growth- and quality-related characteristics and to determinate the optimum seeding date and harvesting time for snap bean. Pod yield was significantly affected by seeding date. The highest pod yield was obtained from March 20 for determinate type and April 4 for indeterminate one, respectively, with the range of 13.0-23.7 t/ha. The pod length of indeterminate type was over 13cm, and the pod length was over 5 grams. The pod width for tested varieties was less than 1.0cm. Considering the pod growth characters such as pod length, pod width, and pod weight, the optimum harvesting time for immature pods of snap bean was supposed to be from 15 to 20 days after flowering. The daily yield of snap bean was begun to sharply increase from 15 days after the first flowering and the maximum yield was recorded at 30 days after flowering. For the accumulated yield, nearly 90% of total yield was obtained in 42 days after flowering.