• The Korean Journal of Mycology
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• v.41 no.3
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• pp.197-199
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• 2013

The sclerotium rot of corn (Zea mays L.) occurred sporadically at the experimental field of Gyeongsangnam-do Agricultural Research and Extension Services in July 2011. The infected stems were water-soaked, wilted, and finally led to the death of the whole plants. White mycelial mats were spread over lesions, and then sclerotia were formed on stem and near soil line. The sclerotia were globoid in shape, white to brown in color and 1-3 mm in size. The hyphal width was $4-8{\mu}m$. The optimum temperature for mycelial growth and sclerotia formation on PDA was 30 on PDA. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report of sclerotium rot on corn caused by S. rolfsii in Korea.

• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.617-622
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• 2003

Experimental designs were applied to optimize the mixture ratio for the extrudate made by soymilk residue and corn grits. Nine candidate points were examined for their significance on extrudate using the modified distance design. Bending force, expansion ratio, bulk density, water solubility index (WSI), water absorption index (WAI) and color $(L^*,\;a^*,\;b^*)$ were the significant factors improving the extruded cereal production, and these values were applied to the mathematical models. Results showed that bending force, expansion ratio WSI, WAI and color $(L^*,\;b^*)$ increased with increasing the corn grits, whereas bulk density tended to decrease. The statistical study showed that the fitted models were adequate to describe the contour plot and all responses. Optimum mixture ratio allowing to maximize the two responses (expansion ratio and $b^*$) and minimize the response (WAI) were examined with a numerical optimization methods. The numerical optimization method was obtained as 53.18% : 46.19% (corn grits : soymilk residue).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.2
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• pp.91-97
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• 2010

The growth, yield and chemical properties of waxy corn $Sonjajang{\times}KNU-7$ and $Asan{\times}KNU-7$ planted in different dates and mulch types in a converted paddy field was investigated. Experiment was carried out in a randomized complete block design in a split split-plot arrangement with four replications. Planting dates (D) [May 16 (D1, early), June 1 (D2, middle), June 6 (D3, late)] represented main plots, plastic mulch (M) [(BM, black mulch; TM, transparent mulch)] for subplots while waxy corn crosses [$Sonjajang{\times}KNU-7$ (‘Sonja’) and $Asan{\times}KNU-7$ (‘Asan’)] for sub-subplots. Results showed that D had a significant effect on growth characters except emergence, ear quality except ear diameter, and yield whereas M showed significant effect on growth characters only. Superior growth and ear quality performance were recorded in D1 and BM. In terms of crosses, ‘Sonja’ had better growth performance than ‘Asan’ regardless of D and M, but performed better at D1 and BM. Highest yield was obtained in D1 for BM (2,131 kg $10a^{-1}$) and TM (1,655 kg $10a^{-1}$) but no significant difference in the yield across V was recorded. In terms of starch and sugar contents, a decreasing trend was observed from D1 to D3 regardless of M and V.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.144-148
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• 2020

Corn silk (Okmi-su) was anciently adopted as a material for tea or beverage. Corn silk extracts (CSE) contain bioactive phytochemicals such as phenolic acid, flavonoids, ascorbic acid, tannins, and glycosides. Under the impact of these functional components, CSE has benefits for antioxidation, diuresis, anti-diabetes, and dyslipidemia recovery. Nonetheless, its role in whole-body adiposity was not investigated; therefore, the effects of CSE on obesity were evaluated in high-fat diet-induced obese mice. Mice were assigned to either group (n=12); 1) normal diet (18% kcal from fat), 2) high-fat diet (45% kcal from fat, the control), 3) high-fat diet with CSE (800 mg/kg diet), and 4) high-fat diet with orlistat (500 mg/kg diet, a comparable control for weight loss). Our results showed that body weight, adiposity, and energy expenditure in obese mice were not altered by CSE. Lean body mass tended to decrease by CSE, which can be explained by stimulation of diuresis (p=0.06). In conclusion, our results suggest that dietary consumption of CSE does not influence the adiposity and underlying substrate utilization in high-fat diet-induced obese mice.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.979-984
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• 2000

To improve the quality of dehydrated onion, antibrowning agents were screened. Effects of antibrowning agents on the degree of browning and the quality characteristics in dried onions were investigated. Sliced onions were dehydrated in an air drier at $70^{\circ}C$ within 3 percent moisture. Among various antibrowning agents, cyclodextrin and corn starch treatments were selected. Dipping in 4%(w/v) corn starch suspension proved more effective in preventing browning than other treatments. The change of color and the degree of browning showed a correlation. Dried onions treated with antibrowning agents prevented browning at around $24{\sim}32%$ compared to control. The contents of reducing sugar and vitamin C in treated onions had minimally changes.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.279-283
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• 2009

A new yellow waxy corn hybrid "Daehakchal Gold 1" was developed from single cross between Yeongdeok Jaera and Okchen Jaera at Chungnam National University in 2007. Inbred CNU57 derived from Yeongdeok Jaera was used as the seed parent of Daehakchal Gold 1, and inbred CNU 27 derived from Okchen Jaera as the pollen parent. Tasseling date of this hybrid was seven day later than that of check hybrid, Chalok 1. Daehakchal Gold 1 was 19.7cm in ear length and 4.5cm in ear diameter. The yield of Daehakchal Gold 1 and check hybrid in dry matter were 146.5g and 113.9g per plant, respectively. On yield trial, which were increased 29.7% compared with a check hybrid, Chalok 1. Especially, Daehakchal Gold 1 had yellow kernels and good eating quality. The ratio of kernel set length/ear length was similar to Chalok 1. It is moderately resistant to Bioporalis maydis and corn borer. The yields of Daehakchal Gold 1 in fresh ear weight and in number of fresh ear were 16% and 8%, respectively, higher than those of a check hybrid in regional yield trials for three years. Seed production of this hybrid has gone well due to good match during crossing between seed and pollen parents.

• Korean Journal of Remote Sensing
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• v.22 no.3
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• pp.183-197
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• 2006

Combinations of visible and near-infrared (NIR) bands in an image are widely used for estimating vegetation vigor and productivity. Using this approach to understand within-field grain crop variability could allow pre-harvest estimates of yield, and might enable mapping of yield variations without use of a combine yield monitor. The objective of this study was to estimate within-field variations in crop yield using vegetation indices derived from hyperspectral images. Hyperspectral images were acquired using an aerial sensor on multiple dates during the 2003 and 2004 cropping seasons for corn and soybean fields in central Missouri. Vegetation indices, including intensity normalized red (NR), intensity normalized green (NG), normalized difference vegetation index (NDVI), green NDVI (gNDVI), and soil-adjusted vegetation index (SAVI), were derived from the images using wavelengths from 440 nm to 850 nm, with bands selected using an iterative procedure. Accuracy of yield estimation models based on these vegetation indices was assessed by comparison with combine yield monitor data. In 2003, late-season NG provided the best estimation of both corn $(r^2\;=\;0.632)$ and soybean $(r^2\;=\;0.467)$ yields. Stepwise multiple linear regression using multiple hyperspectral bands was also used to estimate yield, and explained similar amounts of yield variation. Corn yield variability was better modeled than was soybean yield variability. Remote sensing was better able to estimate yields in the 2003 season when crop growth was limited by water availability, especially on drought-prone portions of the fields. In 2004, when timely rains during the growing season provided adequate moisture across entire fields and yield variability was less, remote sensing estimates of yield were much poorer $(r^2<0.3)$.

• Korean Journal of Remote Sensing
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• v.14 no.4
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• pp.343-352
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• 1998

Spectral reflectance data of upland crops at OSMI bands were collected and evaluated for the feasibility of crop discrimination knowledge-based on crop calendar. Effective bands and their ratio values for discriminating corn from two other legumes were defined with OSMI equivalent bands and their ratio values. For corn discrimination from two other legumes, peanut and soybean, June 22 among measurements dates was the best since all OSMI equivalent bands and their ratio values in June 22 were highly significant for corn separability. Phenological growth stage of a silage corn (rs510) could be estimated as a function of spectral reflectance in vegetative stage. Five growth stage prediction models were generated by the SAS procedures REG and STEPWISE with OSMI equivalent bands and their ratio values in vegetative stage.

• The Korean Journal of Food And Nutrition
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• v.35 no.2
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• pp.106-115
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• 2022

The purpose of this study was to examine the quality characteristics of byeolmijang prepared several roasted whole grain powders (oat, brown rice, black soybean, corn) for eight weeks. As the fermentation progressed, the pH decreased from 6.10~6.12 to 4.48~4.92 and the total acidity increased dramatically from 0.41~0.48% to 1.67~2.24%. There were no differences in the moisture content. The content of reducing sugar decreased, in particular, brown rice sample(C) decreased significantly than the other samples during fermentation. In color, L and b-value decreased all samples, whereas a-value showed a tendency to slightly increase. The total cell counts and lactic acid bacteria revealed an increasing tendency during fermentation. In case of the amino-type nitrogen contents, it increased significantly during the fermentation period, especially control sample (A) showed the highest content significantly. The total polyphenol of all samples increased in the fermentation period. ABTS and DPPH radical scavenging activities also increased, especially corn sample (E) had the highest levels. In by electronic tongue analysis, corn sample (E) revealed higher umami and sourness than the control. So, by adding roasted corn powder, it can enhance function and taste of byeolmijang.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.3
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• pp.53-61
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• 2022

This study evaluated the impacts of subsurface drainage design, i.e., spacing and depth, on agricultural productivity and environmental sustainability in two tile-drained fields (Sites A and E) under a corn-soybean rotation in the Midwestern United States. A calibrated and validated Root Zone Water Quality Model (RZWQM) was used to simulate Nitrate-N (nitrogen) losses to tile drainage and crop yields of 30 tile spacing and depth scenarios over 24 years (1992-2015). Our results presented that the narrower and deeper the tile drains are placed, the greater corn yield and Nitrate-N losses, indicating that the subsurface drainage design may cause a trade-off between agricultural productivity and environmental sustainability. The simulation results also presented that up to about 255.7% and 628.0% increase in Nitrate-N losses in Sites A and E, respectively, far outweigh the rate of increase in corn yield up to about 1.1% and 1.6% from the adjustment of tile spacing and depth. Meanwhile, the crop yield and Nitrate-N losses according to the tile configuration differed depending on the field, and the soybean yield presented inconsistent simulation results, unlike the corn yield, which together demonstrate the heterogeneous characteristic of agro-environmental systems to a subsurface drainage practice. This study demonstrates the applicability of agricultural systems models in exploring agro-environmental responses to subsurface drainage practices, which can help guide the introduction and installation of tile systems into farmlands, e.g., orchards and paddy fields, in our country.