• Horticultural Science & Technology
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• v.33 no.4
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• pp.618-623
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• 2015

The new white calla lily (Zantedeschia aethiopica) cultivar 'White Cutie' was bred at the National Institute of Horticultural & Herbal Science (NIHHS) in 2011. 'Childsiana' showing the multi-flowering characteristic and 'Wedding March' resistant to soft rot disease were artificially crossed in 2004. Of the progeny, 'White Cutie' was selected specifically for use in cut flower production after investigation over seven years (2005 to 2011) of genetic and phenotypic characteristics, resistance against soft rot, and customer preference regarding the culture vigor and post-harvest quality. 'White Cutie' was early flowering (85.6 days to flowering) with white flowers (RHS W155C), although it had a mid-sized flower in which spathe height and width were 8.6 cm and 8.7 cm, respectively. It was multi-flowering (6.2 flowers per plant) and produced a very high number of cormels (13.4 per plant). Furthermore, it was resistant to soft rot disease.

• Plant Resources
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• v.4 no.1
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• pp.31-35
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• 2001

Major characteristics of new Waesungri maize inbred line has multi-tiller and ears: five to six tillers and seven to eight ears per plant and flowering date of Waesungri was delayed about 18 and 24 days compared to Mo17 U.S line and IK$_4$ Korean local lines, respectively. Number of ears, fresh and dry weight per plant were significantly different among all tested hybrids including Waesungri/Sinkihong hybrid under different planting times and densities. Especially, both fresh and dry weight of IK$_1$/FR140//Waesungri F$_1$hybrid were significantly higher at high planting density. In kernel weight per unit area, Wnesungri/Sinkihong hybrid was high at high density and IK$_1$/FR140//Waesungri hybrid was high at low planting density. As results of analysis of variance, flowering date was shown a significantly different both planting times and varieties, while other characters including stem height were shown very variable in interactions with enviromental factors.

• 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.

• The Korean Journal of Pesticide Science
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• v.17 no.1
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• pp.1-5
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• 2013

This study was conducted to the amount of pesticide residue in 21 different kinds of 100 commercial flowering teas. Multi-residue analyses of 203 pesticides was performed using the GC-ECD, GC-NPD, GC-MSD, and LC-MS/MS. Pesticide residues were detected in 4 samples (4%) of which 4 samples (4%) violated the maximum residue limits. 4 samples violating the limit were all imported teas. Pesticides detected were chlorpyrifos, flufenoxuron, lufenuron, pyrimethanil and methoxyfenozide. These results indicate the need of continuous monitoring of pesticide residue needs for safety of flowering teas.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.6
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• pp.155-164
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• 2023

Sedirea japonica is one of the critically endangered species in South Korea mostly due to artificial harms such as illegal collection and habitat destruction. Therefore, artificial propagation through improving germination rate, increasing growth, and controlling flowering is meaningful for the conservation and reintroduction of S. japonica. It is suggested that cytokinins are one of the multi-factors that contribute to plant growth and floral responses. Especially, exogenous cytokinins have been known to induce or promote shoot growth or earlier flowering in orchids. Therefore, it was investigated how the application of 6-benzylaminopurine (BA) influenced the growth and inflorescence of S. japonica. A foliar spray containing BA at 100, 200, 300, and 400 ppm was applied from 1st July to 30th December 2021. Leaf length, leaf length growth rate, leaf width, and width and length ratio were measured as growth-related factors. Visible inflorescence rate, inflorescence length, the number of flowers per inflorescence, and the distance between the stalks were measured as flowering-related factors. Growth-related factors except for leaf growth rate were not affected by BA treatments, while leaf growth rate was significantly increased by 200 ppm of BA treatment. The visible inflorescence rate increased by 200 ppm of BA treatment, and there seems an optimal concentration and threshold of BA treatment. An iterative experiment with more seedlings and measurement factors would be helpful to figure out the effects of exogenous BA treatment on S. japonica, and it can be applied for mass propagation.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.136-145
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• 1998

This study was conducted to determine the growth characteristics, and the effect of plant growth regulators on the sprouting and growth of purple nutsedge(Cyperus rotundus L.) in order to establish effective control system in lawn ground. The flowering of purple nutsedge was initiated 30 days after transplanting regardless of the transplanting time. Low temperature less than $10^{\circ}C$ after flowering was required for tuber formation, showing that the tuberization was related to air temperature. Shoot number and dry weight of underground portion of purple nutsedge was slightly affected by plant growth regulators such as benzylamino purine, abscisic acid, brassinosteroid and jasmonate. Imazaquin applied at 1, 2 and 3 weeks after transplanting induced multi-shooting and inhibited shoot growth indicating that the herbicide played a role as plant growth regulator at a concentration of 30 and 60g ai/10a. The greatest inhibition of purple nutsedge was obtained by pyrazosulfuron-ethyl as applied 1 weeks after transplanting, showing almost 100% control of purple nutsedge. Tuber of purple nutsedge composed of 61.83% of moisture, 31.60% of carbohydrates, 4.03% of crude protein, 1.57% of crude fat and 0.97% of crude ash.

• Journal of Ecology and Environment
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• v.30 no.3
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• pp.225-229
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• 2007

The mating systems of natural populations of Potentilla freyniana in Korea were determined using allozyme analysis. The result suggests that P. freyniana is outcrossing as well as employing vegetative reproduction by stolon (self-fertilization rate, s < 0.5). The values of the inbreeding coefficient of eight populations in Korea varied from 0.244 to 0.331, with an average value of 0.274. For eight natural populations, multi-locus estimates of outcrossing (tm) was 0.603 across 13 polymorphic loci, with individual population values ranging from 0.530 to 0.652. The relatively low outcrossing rates of some populations could be attributed to extensive vegetative reproduction by stolon and the isolation of flowering mature plants. Although P. freyniana usually propagated by asexually-produced ramets, I could not rule out the possibility that sexual reproduction occurred at a low rate because each ramet may produce terminal flowers. Although heterozygote excess was observed in some natural populations, most populations exhibited varying degrees of inbreeding and a heterozygote deficit.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.101-105
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• 2012

'Secret Pink' was released by National Institute of Horticultural & Herbal Science in 2008. The cross was made between '03B1-23' and 'Sei-Monaco in 2005'. After the evaluation of the characteristics under shade culture in summer and retarding culture in spring and consecutive selection from 2006 to 2008, 'Secret Pink' was selected finality. The natural flowering time of 'Secret Pink' was the middle of October, and it is possible to flower all year round by shade and light culture. It has single type flowers with pink petals. The growth of plant was very vigorous and response time was 6.5 weeks. The diameter of flower was 6.7 cm. Number of flowers per stem and petals per flower were 14.5 and 25, respectively. Days to flowering under the short day treatment was about 50 and its vase life was 25.5 days in autumn season.

• Korean Journal of Breeding Science
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• v.42 no.3
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• pp.248-251
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• 2010

A lemon double freesia (Freesia hybrida Hort.), 'Shiny Lemon' was developed from a cross between the domestic breeding lines ('Golden Crown' and 'White Wings') and 'Yvonne' followed by seedling and line selections at the National Institute of Horticultural and Herbal Science, Rural Development Administration (RDA) in 2007. Growth and flowering characteristic tests were conducted from 2003 to 2006. 'Shiny Lemon' has large double type flower with lemon color (RHS Y13D). It has multiple florets, good flower shape, and upright leaves and stalks. The average cut flower yield of 'Shiny Lemon' was 7.1 cuttings per plant in the greenhouse from 2005 to 2007. Additionally, it has good production of cormlets and vigorous growth. 'Shiny Lemon' could be cultured under greenhouse conditions in Korea.

• Korean Journal of Environmental Agriculture
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• v.22 no.4
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• pp.294-299
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• 2003

The seeds of naturally growing Heteropappus hispidus (Thunb.) were treated by nine different doses (0, 10, 20, 40, 80, 120, 160, 200, 300, 400 Gy) of gamma rays to investigate their germination rate and to quantity the characteristics of their germinated plants as like as leaf appearance and length, the formation rate of anthocyanin color in stem 30 days after germination, the formation rate of rosette leaf and multi-shoot, the flowering and seed-bearing, and shoot length. The germination rate at least up to 120Gy was not greatly affected but was rapidly decreased at over 160Gy. It seemed that lethal dose ($LD_{50}$) of germination was 160Gy. The leaf appearance and growth was also inhibited, but the formation rate of anthocyanin color in the flower stem was enhanced up to 30% with dose. The rosette plants were observed in plants irradiated with higher than 40Gy. Multi-shoots were developed over 80Gy. For a short shoot length and bundle of thin stem, it was considered that they can be selected as the potential pot flower plants, through genetic fixation. In particular, it was suggested that the formation of anthocyanin color in flower stem, rosette and multi-shoot plants induced by the high dose of gamma rays could be utilized as the morphological markers for the mutant selection of Heteropappus hispidus (Thunb.).