• Journal of Animal Science and Technology
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• v.66 no.5
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• pp.949-961
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• 2024

The annual forage crop production system, enclosing silage corn (Zea mays L.) and following cool-season annual forage, can enhance forage production efficiency where available land is limited for pasture production. In this forage production system, successful silage corn cultivation has a significant value due to the great yield of highly digestible forage. However, some untimely planting or harvesting of corn due to changing weather often reduces biomass and feeding values. Therefore, a study was conducted to quantify the corn silage biomass reductions by the deviations from optimum planting soil temperature and optimum growing degree day (GDD). The approximations of maximum corn production were estimated based on field trial data conducted between 1978 and 2018 with early, medium, and late-maturity corn groups. Based on weather data, the recorded planting dates and harvest dates were converted into the corresponding trials' soil temperatures at planting (STP) and the GDD. The silage corn biomass data were regressed against STP and GDD using a quadratic function. The maximum biomass point was modeled in a convex upward quadratic yield curve and the optimum STP and GDD were defined as those values at the maximum biomass for each maturity group. Optimized STP was at 16.6℃, 16.2℃, and 15.6℃ for early, medium, and late maturity corn groups, respectively, while optimized GDD at harvest was at 1424, 1363, and 1542℃. The biomass reductions demonstrated quadratic functions by the departures of STP or GDD. The 5% reductions were anticipated when STP departed from the optimum temperature by 2.2℃, 2.4℃, and 1.4℃ for early, medium, and late maturity corns, respectively; the same degree of reductions were estimated when the GDD departed by 200, 180, and 130℃ in the same order of the maturity groups. This result indicates that biomass reductions of late-maturity corn were more sensitive to the departures of STP or GDD than the early-maturity corn. Therefore, early maturing cultivars are more stable in biomass production in a silage corn-winter annual forage crop production system to enhance forage-based livestock production efficiency.

• Journal of The Korean Society of Grassland and Forage Science
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• v.9 no.2
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• pp.113-118
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• 1989

This experiment was carried out to compare chemical composition, TDN yield of corn-soybean intercropping and corn monocropping forage plants at different harvesting time and obtained the following results. 1. In both cropping systems, the content of chemical composition of forage were changed same pattern in growing stage. The content of crude protein in corn-soybean intercropping forage at yellow stage increased more than that of corn nonocropping forage, while the crude fat in corn monocropping forage plants increased than that of corn-soybean intercropping forage plants at mature stage. 2. The crude fiber, crude ash, ADF content of forage plants in both cropping system decreased same pattern in growing period, however, NFE content of forage increased with maturity. 3. TDN yield of corn-soybean intercropping and corn monocropping forage plants at yellow stage obtained similar results and TDN yield per 10a in intercropping and monocropping were 1006.lkg and 978.6kg, respectively. 4. Consequently, corn-soybean interaopping system could be increased crude protein yield without decreasing of dry matter yield in comparison with corn monocropping system for corn silage.

• Korean Journal of Remote Sensing
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• v.28 no.6
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• pp.597-609
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• 2012

Leaf area index (LAI) is important in explaining the ability of the crop to intercept solar energy for biomass production and in understanding the impact of crop management practices. This paper describes a procedure for estimating LAI as a function of image-derived vegetation indices from temporal series of IKONOS, Landsat TM, and MODIS satellite images using empirical models and demonstrates its use with data collected at Missouri field sites. LAI data were obtained several times during the 2002 growing season at monitoring sites established in two central Missouri experimental fields, one planted to soybean (Glycine max L.) and the other planted to corn (Zea mays L.). Satellite images at varying spatial and spectral resolutions were acquired and the data were extracted to calculate normalized difference vegetation index (NDVI) after geometric and atmospheric correction. Linear, exponential, and expolinear models were developed to relate temporal NDVI to measured LAI data. Models using IKONOS NDVI estimated LAI of both soybean and corn better than those using Landsat TM or MODIS NDVI. Expolinear models provided more accurate results than linear or exponential models.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.1
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• pp.59-66
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• 1997

This experiment was conducted at the forage experimental field, College of Agriculture and Life Sciences, Seoul National University, Suweon in 1992 and 1993 to investigate the effects of tillage method-conventional and rotary-till, rye (Secde cereale L.) harvest date-early (April 14) and late (April 26), and rye residue treatmentno paraquat(1, 1-dinethyl-4,4'-bipyridinium dichloride) and paraquat in minimizing the adverse effects of the rye residue on growth and yield of succeeding corn(Zea mays L.). Corn plant height during the growing season was slighly taller with conventional tillage relative to rotary-till when rye was harvested in early and treated by paraquat. Corn LA1 during the growing season was slighly increased when rye was harvested in early and where conventional tillage was used with paraquat treatment. There were no differences in the leaf number and silking dates of corn among the tillage methods, harvest dates of rye and paraquat treatments. The dry matter yield of corn was significantly increased by paraquat treatment when rye was harvest in early, but no differences were found in the dry matter percentage, ear percent to total dry matter, and stover, ear and estimated TDN yields of corn among the treatments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.17 no.4
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• pp.323-328
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• 1997

Com(Zea mays L.) hybrid is recognized as the principal cmp in a double-cmpping system. Rye(Secale cereale L.), seeded after corn hybrid harvest, is the second crop in the system. Under this forage production system, corn planting is mostly delayed beyond mid-May due to delayed rye harvest on May, but the corn should be harvested until mid-August before the autumn rain started. It is for this reason that early maturing corn hybrids are preferred for silage crops in this system. Twenty eight cultivars of early maturing corn hybrids evaluated in this experiment at three locations (Suweon, Sunghwan and Cheju) for 3 yr(1994-1996) were compared for agronomic characteristics, forage yield and quality. Among the com hybrids tested, DUO1 and GL499 were recommended as the government superior corn hybrids due to their promising agronomic traits, such as short plant and ear heights, adquate dry matter percentage for silage on mid-August, good staygreen along with good lodging and disease resistance, better ear retention, similar yield compared to the control hybrid, Suweon 19 and above average stover quality.

• Agricultural and Biosystems Engineering
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• v.7 no.1
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• pp.18-26
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• 2006

In-field site-specific nitrogen (N) management increases crop yield, reduces N application to minimize the risk of nitrate contamination of ground water, and thus reduces farming cost. Real-time N sensing and fertilization is required for efficient N management. An 'on-the-go' site-specific N management system was developed and evaluated for the supplemental N application to com (Zea mays L.). This real-time N sensing and fertilization system monitored and assessed N fertilization needs using a vision-based spectral sensor and controlled the appropriate variable N rate according to N deficiency level estimated from spectral signature of crop canopies. Sensor inputs included ambient illumination, camera parameters, and image histogram of three spectral regions (red, green, and near-infrared). The real-time sensor-based supplemental N treatment improved crop N status and increased yield over most plots. The largest yield increase was achieved in plots with low initial N treatment combined with supplemental variable-rate application. Yield data for plots where N was applied the latest in the season resulted in a reduced impact on supplemental N. For plots with no supplemental N application, yield increased gradually with initial N treatment, but any N application more than 101 kg/ha had minimal impact on yield.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.326-333
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• 1985

The genetic information was required to improve several plant characteristics of the two modified opaque-2 synthetics, which were synthesized in 1980 at the Chungnam National University. Genetic analysis to obtain the information was carried out by the method of Hallauer and Wright. The information obtained from the analysis indicates that plant characteristics such as plant height, ear height, kernel weight and yield of the two synthetics can be improved by proper breeding procedures, since these characteristics were showing high estimates of genetic and additive variance. The study also shows that some characteristics such as ear length or kernel row number may be not improved effectively and with ease.

• Korean Journal of Pharmacognosy
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• v.37 no.4 s.147
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• pp.307-313
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• 2006

Reactive oxygen species (ROS) and formation of advanced glycation end products (AGEs) play an important role in the pathogenesis of diabetic nephropathy by hyperglycemia. To find natural agents improving diabetic nephropathy, 63 natural resources which used to the treatment of diabetes mellitus in a folk remedy were investigated with an in vitro system employing radical scavenging activity and inhibitory activity of AGEs formation. In results, the extracts of Aspalathus linearis, Rubus coreanus, Rosa rugosa, and Epimedium koreanum significantly inhibited the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical with $IC_{50}$ values less than $10{\mu}g/ml$. The extracts of Zea mays, Cucurbita moschata, Cudrania tricuspidata, and Aspalathus linearis effectively reduced the formation of AGEs compared with the positive control $N-acetyl-_L-cystenine$ (NAC) and aminoguanidine (AG). In addition, the extracts of Aspalathus linearis, Commelina communis, Cornus officinalis, and Lespodeza cuneata showed the all inhibitory activity against DPPH radical and AGEs formation. Also, these resources definitely showed the radical scavenging activity against peroxynitrite $(ONOO^-)$ and hydroxyl radical $({\cdot}OH)$ relating to high glucose-induced ROS production. Thus, these results suggest that some natural resources may regulate the initiation and progression of diabetic nephropathy through inhibition of ROS production and AGEs formation.

• The Korea Journal of Herbology
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• v.25 no.4
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• pp.151-160
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• 2010

Objectives : The purpose of this research was to examine dietary therapy on the edema based on the literary findings, for clinical treatment and prevention of the edema. Methods : This Research was examined on histories, compositions, applications, and effects of dietetic treatment about 100 cases of dietary therapy of the edema from Chinese literatures. Results : 1. Various vegetables and animals including herbs, grains, vegetables, fruits, food and drink were used for the dietary therapy. 2. Methods of the preparation for use as therapeutics were decoction, pulvis, gruel, cake, tea, paste, gelatin and etc. 3. Frequently used materials were Cyprinus carpio Linnaeus, Cucumis sativus L. Coix lachrymajobi var. mayuen, Zea mays, Maydis Stigma, Citrullus vulgaris, Zingiber officinale, Cinnamomum cassia Blume, Allium scorodorpasum var. viviparum Regel, Camellia sinensis, Armeniacae amarum Semen, Phyllostachys bambusoides, Luffa cylindrica, Dioscorea batatas Decne, Panax ginseng, Brassica oleracea and Raphanus sativus. Conclusion : Though dietary therapy for the edema is not based on clinical or experimental data, but through experience. It is mostly based on Yin-Yang and five elements, visceral manifestation, channels and their collateral channels and Oriental herbal medicine theories. If we use them properly according to oriental medicine method, it will be effective on treating and preventing the edema.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.429-433
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• 1996

A Giemsa C-banding method was used for the identification of somatic chromosomes of Korean indigenous maize(Zea mays L.). Two Korean indigenous maize stocks and an American hybrid maize for comparison were examined. Ten deeply stained heterochromatic knobs whose position and size were different between the genotypes, two satellites and interstitial bands were observed. The length of homologous chromosomes compared by the relative lengths of chromosomes presented as a percentage of the length of chromosome 10 were different between the genotypes. The Giemsa method proved to be useful for the identification of somatic chromosomes and for the characterization of different stocks of Korean indigenous maize.