• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.76-83
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• 1984

This experiment was performed to investigate the flowering habit of sesame (Sesamum indicum L.). Sesame varieties tested could be classified into 8 different plant types by their morphological traits such as capsule shape, capsule setting habit and branching types among sesame gene pool of Crop Experiment Station, ORD. The first flower was appeared at the lowest node on main stem. Flowers were appeared progressively toward the tip of the main stem and also toward the tips of branches. The interval of flowering for a node was about one day, but 3 to 8 days for the flowers on the tips. Side flowers started at 4 to 5 nodes lower than those of center flower at the same day. Flowers were beared 2 by 1 node on the middle part of flower setting node (7-9) in mono capsule setting habit in spite of its normal is 1 by 1 node on the other nodes. Flowers were beared opposite direction on each node of stem and flowering toward the tip of main stem composed of cross shape between nodes and spiral, reverse of clockwise direction. We called this habit as cross spiral flowering order and cross spiral phyllotaxis. The first flower on branches was appeared when center flower on the 5th node of main stem began to flower. The branches produced at higher nodes on main stem showed larger flowering periods and more number of flowers than that at lower parts. BTB (Branch, Tricapsule, Bicarpels, 4 Loculi) type showed three capsule setting habits and same flowering period both on main stem and branches while BTQ (Branch, Tricapsule, Quadricarpels, 8 Loculi) type showed three capsule setting habit on main stem and mono-capsule setting habit on branches. In BTQ type, the period of flowering was much shorter on branches than on main stem. Branching type was considered more promising than non branching type for the breeding of early maturing high yielding variety because branching type has the advantage of bearing a lot of flowers in comparatively short flowering period.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.529-533
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• 2009

A new spray chrysanthemum (Dendranthema grandiflorum) cultivar "Green Witch" was developed from a cross between 'S04161' and 'S04109' by selection of seedlings and lines at the Flower Research Institute, Gyeongnam Agricultural Research and Extension Services (ARES) from 2004 to 2008. Its characteristics were investigated three times from 2006 to 2008 under condition of forcing culture in spring and retarding culture in autumn. The natural flowering time of "Green Witch" was October 19th, and year-round production was possible by day length treatment. Its capitulum was 3.2cm in diameter, and had 15.9 head per stem in autumn. Its ray floret was green central zone. To flower in the short day condition, for "Green Witch" was about 44 days in spring, and "Green Witch" showed the vase life of 25.3 days in autumn. This cultivar was registered for a commercialization in 2008.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.1
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• pp.42-54
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• 2016

It is highly anticipated that warming temperature resulting from global climate change will affect the phenological pattern of kiwifruit, which has been commercially grown in Korea since the early 1980s. Here, we present the potential impacts of climate change on the variations of flowering day of a gold kiwifruit cultivar, Haegeum, in the Jeonnam Province, Korea. By running six global climate models (GCM), the results from this study emphasize the uncertainty in climate change scenarios. To predict the flowering day of kiwifruit, we obtained three parameters of the 'Chill-day' model for the simulation of Haegeum: $6.3^{\circ}C$ for the base temperature (Tb), 102.5 for chill requirement (Rc), and 575 for heat requirement (Rh). Two separate validations of the resulting 'Chill-day' model were conducted. First, direct comparisons were made between the observed flowering days collected from 25 kiwifruit orchards for two years (2014-15) and the simulated flowering days from the 'Chill-day' model using weather data from four weather stations near the 25 orchards. The estimation error between the observed and simulated flowering days was 5.2 days. Second, the model was simulated using temperature data extracted, for the 25 orchards, from a high-resolution digital temperature map, resulting in the error of 3.4 days. Using the RCP 4.5 and 8.5 climate change scenarios from six GCMs for the period of 2021-40, the future flowering days were simulated with the 'Chill-day' model. The predicted flowering days of Haegeum in Jeonnam were advanced more than 10 days compared to the present ones from multi-model ensemble, while some individual models resulted in quite different magnitudes of impacts, indicating the multi-model ensemble accounts for uncertainty better than individual climate models. In addition, the current flowering period of Haegeum in Jeonnam Province was predicted to expand northward, reaching over Jeonbuk and Chungnam Provinces. This preliminary result will provide a basis for the local impact assessment of climate change as more phenology models are developed for other fruit trees.

• Korean Journal of Plant Resources
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• v.1 no.1
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• pp.42-47
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• 1988

The florescence steps of Lycium chinense M. are as follows: Budding-Yellow, leaf-Falling-Flowering. Pruning treatment has a long stem diameter compared withnon-pruning treatment and as a result, the numbers of internode were great and thetotal effective numbers of branch were great, too. In the non-pruning treatment asthe fruit length was short so the fruit was small, and on the contrary in the pruningtreatment as the fruit length was long so large and good fruits were produced.Fresh fruit weight produced per 10a was increased as much as 38-39% in thesurface pruning treatment and in the pruning treatment l0Cm away from surfacecompared with in the non-pruning treatmerlt.

• 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.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.196-205
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• 2021

This research was conducted in order to analyze the difference in yield through the changes in growth and measuring the photosynthesis efficiency in cherry tomatoes. Seedlings of cherry tomato 'Nonari' were used as scion and non-grafted control, while 4 different grafted tomatoes 'Powerguard', 'T1', 'L1', and 'B.blocking' were used as rootstocks. Plants grafted onto 'B.blocking' produced the highest fruit yield (417.5 g plant^-1), whereas non-grafted plant 'Nonari' had the lowest fruit yield, (354.2 g plant^-1) at the latter period of cherry tomatoes in May. The flowering position in May, plant grafted onto 'B.blocking', showed 14-17 cm, whereas non-grafted plant 'Nonari' showed 10-14 cm. The growth strength on May 15, non-grafted plant 'Nonari', showed 8.43 mm which was the lowest value among the treatments. Grafted plants kept the growth balance until the end of the harvest that led to an increase in fruit yield, while non-grafted plant weakened the vigor earlier that led to a decrease in fruit yield. Grafted plants showed higher values of chlorophyll fluorescence variables than the values of non-grafted plant. These results indicate that grafting influenced fruit yield which was observed as maintaining growth balance for longer and an increase in photosynthesis efficiency compared to non-grafting.

• Korean Journal of Environment and Ecology
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• v.22 no.3
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• pp.221-229
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• 2008

This study observed and compared phenological changes in the spring for some native woody plants growing at Mt. Jumbong and Mt. Bongeui located at central districts of our country, and also inquired into the phenological difference subsequent to microclimate change by measuring its related environment factors as well. The average air temperature at a survey point of Mt. Jumbong from January to May in 2004 was $4.1^{\circ}C$ lower than that of Mt. Bongeui. As for the soil temperature in April by a survey section within Mt. Jumbong, the soil temperature on the west and northwest slopes was $1.8^{\circ}C$ and $4.4^{\circ}C$ lower than that of the south slope, respectively. It was found that the earliest tree species in a flowering period was Lindera obtusiloba among the sample woody plants and its flowering began in late March at Mt. Bongeui and in early April at Mt. Jumbong. The flowering of the same species began faster on the south slope than the west or north slope; in case of the tree species flowering in early spring, there appeared about two-week interval between the survey sites. Likewise, leafing time of the same species was two weeks earlier at Mt. Bongeui(in mid-April) than at Mt. Jumbong(in early May). Nuttonson's Index and Year Day Index for the flowering and leafing time of the same species showed similar value between the survey sites. It is analyzed that the transition in phenological phases between the sites is mainly caused by temperatures; further, it is implied that the climate changes and rise in temperatures could expedite the changes in phenological phases more than ever.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.427-435
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• 2023

Changes in flowering time due to weather fluctuations impact plant growth and ecosystem dynamics. Accurate prediction of flowering timing is crucial for effective forest ecosystem management. This study uses a process-based model to predict flowering timing in 2023 for five major tree species in Korean forests. Models are developed based on nine years (2009-2017) of flowering data for Abeliophyllum distichum, Robinia pseudoacacia, Rhododendron schlippenbachii, Rhododendron yedoense f. poukhanense, and Sorbus commixta, distributed across 28 regions in the country, including mountains. Weather data from the Automatic Mountain Meteorology Observation System (AMOS) and the Korea Meteorological Administration (KMA) are utilized as inputs for the models. The Single Triangle Degree Days (STDD) and Growing Degree Days (GDD) models, known for their superior performance, are employed to predict flowering dates. Daily temperature readings at a 1 km spatial resolution are obtained by merging AMOS and KMA data. To improve prediction accuracy nationwide, random forest machine learning is used to generate region-specific correction coefficients. Applying these coefficients results in minimal prediction errors, particularly for Abeliophyllum distichum, Robinia pseudoacacia, and Rhododendron schlippenbachii, with root mean square errors (RMSEs) of 1.2, 0.6, and 1.2 days, respectively. Model performance is evaluated using ten random sampling tests per species, selecting the model with the highest R². The models with applied correction coefficients achieve R² values ranging from 0.07 to 0.7, except for Sorbus commixta, and exhibit a final explanatory power of 0.75-0.9. This study provides valuable insights into seasonal changes in plant phenology, aiding in identifying honey harvesting seasons affected by abnormal weather conditions, such as those of Robinia pseudoacacia. Detailed information on flowering timing for various plant species and regions enhances understanding of the climate-plant phenology relationship.

• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.456-463
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• 2020

This research was conducted to examine the changes in yield and difference in growth, using rootstocks in tomatoes as the growth indicators. Seedlings of tomato 'Gama', were used as scion and non-grafted control, while 4 different grafted tomatoes 'Powerguard', 'T1', 'L1', and 'B.blocking' were used as rootstocks. The non-grafted and grafted plants were grown in hydroponics for long-duration cultivation under plastic greenhouse conditions. The total yield of grafted tomato 'Powerguard' and non-grafted tomato 'Gama' were 8,428 g and 7,645 g, respectively. The flowering position of grafted plants 'B.blocking' and non-grafted plants at the latter period were 17.58 cm and 14.92 cm, respectively. The results showed that the yield and the balance of the plant were improved until the end of the harvest by grafting. The difference in yield between non-grafted and grafted tomatoes was evident in the 19th cluster, 236 days after planting. Therefore using rootstocks could be advantageous for long-duration cultivation in tomatoes.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.264-268
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• 2007

Flower and fruit characteristics, in 'Hongro' and 'Galaxy Gala' apples, were investigated by bearing branch lengths and flower bud position such as blow 5 cm, $10{\sim}15cm$ and above 20 cm length with terminal bud, and above 20 cm length with axillary bud for investigation on possibility of alternative use of long bearing branch and axillary bud in case of die-back of spur flower bud. In flowering characteristics by flower bud position in the above 20 cm length, the terminal bud was later and was short in flowering period, and also was little in number of flower per bud. Fruit weight, number of seeds, and sugar-acid ratio, in characteristics of ripening fruit, were more the blow 5 cm and $10{\sim}15cm$ length, but soluble solid and malic acid contents was the opposite tendency. In fruit characteristics by flower bud position in the above 20 cm length, the terminal bud had high tendency expected far number of seed in 'Hongro' and Hunter a value of 'Galaxy Gala' apple but had not significant difference. Correlation between fruit weight and number of seed was high. As the results, value of alternative use of long bearing branch in apples had a little expected for fruit weight, especially was more 'Galaxy Gala' and the axillary bud.