• Weed & Turfgrass Science
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• v.4 no.4
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• pp.397-404
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• 2015

This study was conducted to find out the optimum nitrogen fertilization for production of good quality and high yield zoysiagrass (Zoysia japonica Steud.), the changes in chemical properties of soil in pot and field experiments treated with different levels of nitrogen fertilizer. In pot experiment, the fresh and dry weights of shoots and stolons and the number of shoots increased as nitrogen levels increased, and showed no significant between 24 and $48kg\;N\;10\;a^{-1}$. In field experiment, the shoot length, fresh and dry weights of shoots, roots and stolons, the number of shoots and total stolons length linearly increased as affected by increased nitrogen application, and were not significantly different between 24 and $32kg\;N\;10\;a^{-1}$. In both experiments, pH and exchangeable cations ($Ca^{2+}$ and $Mg^{2+}$) in soil decreased as the rate of nitrogen application increased. As a results, chemical properties of soil were more deteriorated in the plots of higher nitrogen fertilizer rate. Thus, these results demonstrated that the nitrogen fertilizer rate for maximum growth of zoysiagrass was $24kg\;N\;10\;a^{-1}$ in consideration of growth and soil condition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.1057-1063
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• 2006

The Dongchimi added with Wasabi (Wasabia japonica Matsum) for the improvement of quality was scientifically explored by reviewing the optimum level and its effect on the microbiological and sensory characteristics of product fermentation. The final weight percentage of Wasabi in Dongchimi was adjusted to 0, 3, 5, 7 and 9%, per radish, respectively. Microbiological and sensory characteristics were determined during fermentation at $10^{\circ}C$ for 55 days. The viable cell counts of total and lactic acid bacteria had increased to their maximum values during fermentation until they began to drop at the later stage. Here, the 7% treatment showed a distinctive low and high numbers of total cells and lactic acid bacteria, respectively, during the later stage of fermentation. As for the sensory evaluation results of the fermented Donchimi with Wasabi, the 7% treatment was most favored for the color, the smell, the sour taste, the hot taste, the carbonated taste, the texture, and the overall acceptability of the products. The optimum levels of Wasabi in Dongchimi were estimated between 5 and 7% per added radish weight, and the 7% level was more preferred when the fermentation-retarding effect of the product was considered.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.269-269
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• 2022

Pre-harvest sprouting (PHS) on rice panicles is getting problematic in recent several years in Korea due to climate changes such as high temperature and more frequent typhoons during harvesting season. PHS negatively affects grain quality severely and also yield. Genetic improvement of Korean varieties (Oryza sativa ssp. japonica) through a marker assisted-backcross breeding (MAB) with the known PHS resistant genes must be one of ideal solutions. However, the final breeding products of MAB occasionally exhibit unwanted traits, especially the cross between genetically distant parents. This might be caused by linkage drag and/or presence of the gene-unlinked donor introgressions, resulting that the final products could not be released to the farmers. The major PHS resistance gene, Sdr4 (Seed dormancy 4) originated from an indica cultivar, Kasalath was selected as a donor gene. In order to avoid unexpected phenotypes in the breeding products, we performed a precision marker-based breeding (PMBB) consisting of foreground, recombinant, and background selections (FS, RS, and BS) which aim to develop 'single small introgression lines' (~100 kb introgression). Korean varieties (Ilpum and Gopum) were crossed with Kasalath. We developed Sdr4-allele specific markers for FS and a set of polymorphic flanking markers near the Sdr4 (-350kb and +420kb) for RS. To minimize linkage drag, the small introgression (< 125kb) containing Sdr4 was selected in Ilpum background (BC₂F₄) through 1^st RS with ~1,200 F₂ or BC₁F₂ plants (one side trimmed) and then 2^nd RS with ~1,000 progenies from the 1^st RS selected plants (another side trimmed). After RS, the selected lines were genotyped by using Infinium 7K SNP chip to detect other donor introgressions and the lines were backcrossed. Currently BS is on-going from the backcross-derived progenies with BS markers to remove residual introgressions. During the PMBB process, genetic effect of Sdr-4-Kasalath allele was confirmed in Ilpum and Gopum backgrounds by PHS phenotyping using the segregating BC₂F₃ or BC₁F₄ materials. The Sdr4 PMBB lines in Ilpum background (< 125kb introgression) will be valuable genetic resources to improve PHS resistance in modem popular temperate japonica varieties.

• Korean Journal of Food Science and Technology
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• v.21 no.2
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• pp.294-299
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• 1989

The quality of dehydrated instant rice produced by a few selected processing methods with short grain milled rice was evaluated. Instant rice produced by process 2 had high rehydration rate, and those by processes 1 and 2 revealed light brown color with less lightness. Instant rice produced by processes 1 and 2 with ammonium carbonate treatment had more uniform porous microstructure, as shown by SEM micrographes, and microstructural difference was noticed between instant rice prepared with government rice and Akibari. Instant rice produced by processes 1 and 2 had less sensory color score, and those by processes 2 and 4 had higher sensory cohesiveness. Overall quality of instant rice produced by process 2 was better, except color.

• Asian Journal of Turfgrass Science
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• v.15 no.4
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• pp.169-179
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• 2001

This study was conducted to determine the effect of root zone cooling on growth and quality of turfgrasses including Kentucky bluegrass (Poa pratensis L.‘Nuglade’), perennial ryegrass (Lolium perenne L.‘Accent’), tall fescue (Festuca arundinacea Schreb.‘Pixie’), and Japanese lawngrass (Zoysia japonica Steud.) in simulated athletic field during summer season in Korea. Mineral contents in clippings of turfgrasses grown at different soil mixtures and temperatures were also analyzed. Root zone cooling (approximately 4~6$^{\circ}C$ lower than that of untreated-control) resulted in good uniformity, little disease incidence and higher level of chlorophyll contents in cool-season turfgrasses. The effectiveness of root zone cooling in protecting disease incidence from high temperature stress was the most manifest in perennial ryegrass compared to others. Fresh clipping weight in treatment of root zone cooling was increased approximately 2 times in Kentucky bluegrass and perennial ryegrass, and 2.5 times in tall fescue compared to those of control. There was higher growth rate in a soil mixture composed of 80% peat moss ＋10% sand ＋10% soil (v/v/v) than in that of 80% pea moss ＋20% sand (v/v), Mineral contents of N, P, K, Ca, and Mg in clippings of three species of cool-season turfgrasses were significantly increased in treat-ment of root zone cooling but this was not found in Japanese lawngrass. Results showed that root zone cooling has a benefit in keeping good quality and growth of cool-season turfgrasses in sports field under supraoptimal ambient temperature during summer season.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.1
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• pp.27-37
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• 1994

To catch the relative importance of varietal and environmental variation in various grain quality components associated with palatability of cooked rice, grain appearance, milling recovery, several physicochemical properties of milled rice and texture or eating quality of cooked rice for rice materials of five japonica cultivars, produced at four locations of the mid-mountainous and alpine area of Korea in 1989, were evaluated and analyzed the obtained data. Highly significant varietal and locational variations were detected in 1000-grain weight, amylose content, K/Mg ratio, gelatinization temperature, peak viscosity, breakdown and setback viscosities as compared with variety x location interaction variation. Also, marked locational variations were recongnized in milling recovery from rough to brwon rice, alkali digestibility and protein content, and significant varietal variation was caught in stickiness /hardness ratio of cooked rice. The variety x location interaction variation was especially large in quality components of grain appearance and ripening, palatability of cooked rice and consistency viscosity. One thousand kernel weight was heaviest in Jinbuolbyeo and Odaebyeo, and the unfilled grain ratio was lowest in Jinbuolbyeo. Odaebyeo showed slightly' lower ratio of intact and clear milled rice because of more chalky rice kernels compared with other cultivars. Amylose content of Jinbuolbyeo and Sobaegbyeo was about 1% lower than that of others and K/Mg ratio of Odaebyeo was the lowest one among rice materials. Odaebyeo, Sobaegbyeo and Jinbuolbyeo revealed significantly low gelatinization temperature and setback viscosity while high peak and breakdown viscosities. Cholwon rice showed the greatest kernel weight, good grain filling but lowest ratio of intact and clear milled rice while Jinbu rices exhibited the highest milling recovery from rough to brown rice and ratio of sound milled rice. Amylose content of milled rice in Jinbu rices was about 2-3% lower than those in other locations. Protein content of polished rice was about 1% lower in rice materials of middle zone than those of southern part of Korea. K/Mg ratio of milled rice was highest in Jinbu rice and potassium content was slightly higher in the rice materials of middle region than in those of southern region. Alkali digestion value and gelatinization temperature of polished rice was markedly high in Jinbu rices as compared with other locations. Breakdown viscosity was hightest in Chlown rices and next higher with the order of Hwaso>Unbong>Jinbu rices, and setback viscosity was the quite contrary tendency with breakdown. The stickiness /hardness ratio of cooked rice was relatively higher value in Cholwon rices than in the others and the palatability of cooked rice was a little better in Unbong and Cholwon rices than in Jinbu and Hwaso rices, although variety x location interaction variation was large. The rice materials can be classified largely into two groups of Jinbu and the others by the distribution on the plane of 1st and 2nd principal components (about 60% of total informations) contracted from twelve grain quality properties closely associated with eating quality of cooked rice. Also, Jinbu and the other rices were divided into two and three rice groups respectively. Varietal variation of overall rice quality was smallest in Hwaso. The most superior rice group in overall quality evaluation included Odaebyeo produced at Cholwon, Unbong and Hwaso, and Sobaegbyeo grown at Unbong

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.581-586
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• 2011

'Cheongdam' is a japonica rice variety developed from a cross between SR19200-HB826-34, a line of good germination ability and shoot emergence at low temperature and Juanbyeo, good quality and direct-seeding adaptable cultivar by the rice breeding team of National Institute of Crop Science, RDA in 2006. This variety has 153 days of total growth duration from seeding to maturity in direct-seeding, and 160 days of growth duration from seeding to maturity in transplanting. This is erect plant type with culm length of 74 cm, thick culm, and green leaves. It has large panicle shape with 126 and 140 spikelets per panicle in direct-seeding and transplanting, respectively. Milled rice is transluscent and medium in grain size of non-glutinous endosperm. This variety is susceptible to leaf and neck blast, bacterial blight, stripe virus disease and brown planthopper. The yield potential of 'Cheongdam' is 5.84 MT/ha at ordinary transplanting culture and 5.62 MT/ha and 5.89 MT/ha at wet direct-seeding and dry direct-seeding cultures, respectively in the local adaptability test for three years. 'Cheongdam' would be adaptable to middle and southern plain of Korea for direct-seeding culture and transplanting rice culture.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.59-68
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• 2011

Research was initiated to investigate the effect of high water-absorbing polymer on turf grass quality of three major turfgrasses. A total of 12 treatment combinations were used in the study. Treatments were made with different rates of sand, soil organic amendment (SOA), and water-swelling polymer (WSP). Visual turf grass quality was evaluated in creeping bentgrass (Agrostis palustris Huds., CB), Kentucky bluegrass (Poa pratensis L., KB), and zoysiagrass (Zoysia japonica Steud., Zoy) grown under greenhouse conditions. Significant differences were observed among the treatments in CB, KB, and Zoy. Visual quality ratings varied with mixing rates of SOA and WSP, being maximum 5.6 in differences among them. At the end of study it ranged from 0.3 to 9.6 in CB, 0.3 to 4.0 in KB, and 0.9 to 5.8 in Zoy. Turfgrass quality pattern changed with time after seeding among treatments influenced by WSP rates. From this study, a proper rate of WSP is considered to be 5%, 5~10%, and 5% for CB, KB and Zoy, respectively. In general, overall treatment effect of WSP on turfgrass quality was highly associated with SOA 20% in three turtgrass species. When mixing sand with SOA and WSP for rootzone soil, a proper rate of SOA is considered to be 15 to 20% for CB and KB, while 20% for Zoy of warm-season grass. A further study would be required to investigate the effect of varied, gradual mixing rates of WSP on growth characteristics of turfgrasses grown on mixtures of sand, SOA, and WSP before a field application.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.2
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• pp.217-224
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• 2014

A total of 150 growing ducks were assigned to five dietary treatments to study the effect of sea tangle and charcoal (STC) supplementation on growth performance and meat characteristics in a completely randomized design. There were six replicates and five ducklings in each replication. The five dietary treatments were control, antibiotic, and 0.1%, 0.5%, and 1% STC supplemented diets. No significant differences were found on ADG, ADFI, and gain:feed among treatments in different weeks. The overall (0 to 3 weeks) ADFI decreased in antibiotic treatment (p<0.05) whereas the gain:feed increased significantly upon 1.0% STC supplementation compared to control (p<0.05). No significant variation was found in meat chemical composition except crude fat content which was high in 1.0% STC dietary group (p<0.05). Meat cholesterol was reduced in 0.1% STC group (p<0.05) compared to other dose levels while serum cholesterol was unaffected. High density lipoprotein (HDL) content was high in 1.0% STC (p<0.05) and low density lipoprotein (LDL) was low in 0.1% and 1.0% STC dietary groups (p = 0.06). No significant effect was found on the thiobarbituric acid reactive substances (TBARS) of fresh meat, whereas the TBARS value of meat preserved for 1 week was reduced significantly in STC dietary groups (p<0.05). The 0.1% STC dietary group showed an increased myristic acid (p = 0.07) content whereas, the content of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids increased in STC supplementation than antibiotic group (p<0.05). An increased concentration of omega-3 fatty acids and a reduced ratio of n-6/n-3 PUFA ratio was found upon 1.0% STC supplementation compared to antibiotic dietary group (p<0.05). Therefore, 1.0% STC dietary supplementation can be used as alternatives to antibiotics in duck production.

• Journal of Practical Agriculture & Fisheries Research
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• v.10 no.1
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• pp.101-111
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• 2008

As the quality of life improves, people want to live in more pleasant environment with beautiful trees, clean air and water. They are keenly interested in environmental issues as well as living environment of apartment which is a trademark of modern life. With this situation, the function and roles of landscaping trees have been recognized as a critical factor to improve living environment. As people have asked for more demands on those trees, it has raised more issues on the defect of trees and is required the solution to those issues. So, the purpose of this study was to survey the reasons of defects and find out those solutions. The data on defects in 1990s was referenced to the reports issued by SH Corporation in 1994 and 1997. The data on defects in 2000s are collected from March, 2006 to May 2006 based on the survey for apartments already constructed by Korea Housing Corporation. The results of the survey were shown that, in the year of 1994, landscaping trees causing high rate of defects were Acer buergerianum (92%), Pinus densiflora(85.7%), Celtis sinensis(80%), Cydonia sinensis(75%) and Diospyros kaki(66.6%), and in the year of 1997, landscaping trees causing high rate of defect were Ziziphus jujuba(100%), Cornus alba(65.2%), Diospyros kaki(60%), Thuja occidentalis(60%), and Metasequoia glyptostroboides(42%). And, in the year of 2006, landscaping trees causing high rate of defect were Sophora japonica(100%), Taxus cuspidata(80%), Magnoila quinquepeta (75%), Acer palmatum(62.5%) and Ginkgo biloba(50%). Because the reasons of defects were various according to the conditions including the climate, location, time and landscaping trees carried into the work area, we present the problems and solutions to those defects. Since the landscaping trees are living creatures, the factors of defects were various and complicated according to the site condition. So, in the period of warranty, contractor should designate the tree manger who can recognize the situation and take suitable action within timely manner.