• Proceedings of the Korean Society of Crop Science Conference
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• 1998.04a
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• pp.81-82
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• 1998

• Research in Plant Disease
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• v.7 no.2
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• pp.69-79
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• 2001

Meloidogyne arenaria race 2 (59%) is widely distributed, followed by M. incognita race 1 (23%), and an unknown race of M. incognita (18 ％) in greenhouses in southern Korea. The key character to distinguish between M. arenaria and M. incognita is excretory pore in female head. When oriental melon, Cucumis melo L., grafted on Shintozoa (Cucurbit maxima x Cu. moschata) is transplanted in February in a plastic tunnel inside a greenhouse infested with M. arenaria, nematodes produced egg masses on roots at 40 days after transplanting and the soil juveniles (J2) population reach maximum in July to 3,817/100 ㎤. Juveniles are distributed relatively uniform over the 180-cm-wide row horizontally and the highest density occurs at 0-25 cm soil depth. For the control of root-knot nematodes, rice rotation, solarization, and soil addition treatments are the most effective (P=0.05); treatments reduce number of J2 over 90% and increase yield two times. Corn retation, fosthiazate, and soil drying treatment are moderately effective, while sesame and green onion rotations are not effective. The relationship between M. arenaria and yield of oriental melon is adequately described by a linear regression model. In the test with wild Cucumis genetic sources introduced from U.S.Dept. of Agriculture (USDA), one of C.heptadactylus, two of C.anguria, two of C. anguria var. longaculeatus, nine of C. metuliferus are resistant to both species of root-knot nematodes.

• Korean Journal Plant Pathology
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• v.14 no.2
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• pp.115-119
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• 1998

Root rot of carnation caused by isolates of Phytophthora was found at Kongju, 1996. Infected plants appeared symptoms of wilting, brown discoloration on collar area and consequently led to death. The causal pathogen was identified as Phytophthora nicotianae based on morphological, cultural and physiological characteristics. Mycelium was grown to rosette colony pattern on corn meal agar and the growth was 10.2 mm/day on 10% clarified V8 medium at $25^{\circ}C$. Swelling with radiating hyphae was formed in water and on agar within 7 days. Chlamydospores were abundantly produced on agar within 7 days. Sporangium was prominent papillate, 2~3 apex, 1.2 : 1 l/b ratio, lateral attacment on sporangiospore and was rarely produced on solid media but produced in water. The shape of sporangium was spherical or ovoid, and the size was 34~73$\times$32~60 (av. 33$\times$66.5) ${\mu}{\textrm}{m}$ in dimension. The isolates were heterothallic, and mating type A2. Oogonium was spherical, ovoid, 26~36 (av. 36 ${\mu}{\textrm}{m}$) in diameter, and antheridium was amphygynious to oogonia. The fungus was able to grow 10~35$^{\circ}C$, and optimal temperature was 27$^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.4
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• pp.546-553
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• 2017

Objective: An experiment was conducted to determine digestible energy (DE) and metabolizable energy (ME) of different byproduct feed ingredients fed to growing pigs, and to generate prediction equations for the DE and ME in feed ingredients. Methods: Twelve barrows with an initial mean body weight of 31.8 kg were individually housed in metabolism crates that were equipped with a feeder and a nipple drinker. A $12{\times}10$ incomplete Latin square design was employed with 12 dietary treatments, 10 periods, and 12 animals. A basal diet was prepared to mainly contain the corn and soybean meal (SBM). Eleven additional diets were formulated to contain 30% of each test ingredient. All diets contained the same proportion of corn:SBM ratio at 4.14:1. The difference procedure was used to calculate the DE and ME in experimental ingredients. The in vitro dry matter disappearance for each test ingredient was determined. Results: The DE and ME values in the SBM sources were greater (p<0.05) than those in other ingredients except high-protein distillers dried grains. However, DE and ME values in tapioca distillers dried grains (TDDG) were the lowest (p<0.05). The most suitable regression equations for the DE and ME concentrations (kcal/kg on the dry matter [DM] basis) in the test ingredients were: $DE=5,528-(156{\times}ash)-(32.4{\times}neutral\;detergent\;fiber\;[NDF])$ with root mean square error = 232, $R^2=0.958$, and p<0.001; $ME=5,243-(153 ash)-(30.7{\times}NDF)$ with root mean square error = 277, $R^2=0.936$, and p<0.001. All independent variables are in % on the DM basis. Conclusion: The energy concentrations were greater in the SBM sources and were the least in the TDDG. The ash and NDF concentrations can be used to estimate the energy concentrations in the byproducts from oil-extraction and distillation processes.

• Korean Journal of Clinical Laboratory Science
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• v.37 no.2
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• pp.129-137
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• 2005

This study was performed to investigate the anti-obesitic effect of mulberry root-bark on male and female Zucker FA/FA or FA/fa rats. Obesity in the rats was induced by feeding high-lipid diet contained 3% corn oil and 1% cholesterol. Experimental groups in male and female rats were assigned to normal diet group (normal control), high-lipid diet group(positive control) and 3% mulberry root-bark powder in high-lipid diet group (MRC). The mulberry treated-group showed decreases of body weight, FER (food efficiency ratio) value and lipid peroxidation in the liver and increase of high density lipoprotein cholesterol (HDL-C) value, compared with positive control groups. Our findings suggest that mulberry root-bark has a potential role in preventing or improving obesity from the following points of view, body weight, serum lipids and antioxidant enzyme activities.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.92.2-93
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• 2003

Severe soybean-sprout rot was found at the mass productive factory in 2000 and 2001 and it caused 10-20％ loss of the production. Pythium sp. was isolated almost 90％ by potato dextrose agar from rotted root and hypocotylsof the sprouts. And the pathogencity tests using test tubes with 2％ water agar and small containers (30 ${\times}$ 30 ${\times}$ 50 cm, WxLxH) cultivation were shown a similar rot on roots and hypocotyls. The fungal mycelium grew rapidly on the water agar and it prevented the seed germination. Density of the Pythium sp. in the recycled water system at the factory was periodically measured using a selective medium, corn meal agar with Pimaricin 10 mg, Rifampicin 10 mg, Ampicillin 100 mg per 1 liter in order to check the contamination of recycled water. After fitering step using 5 and 1 ml in the recycled system was applied and it was effectively controlled Pythium rot. The daily yield of sprout was stable and the occurrenceof Pythium in the recycled water was much less after filtering. The fungal isolates were identified as Pythium deliense Meurs based on various mycological characteristics on corn meal agar and sucrose-asparagine bentgrass leaf culture medium. P. deliens oogonia were spherical, smooth, 19-23 urn in diameter, and their stalk bending toward antheridia. Antheridia were straw hat-shaped, curred club-shaped, therminal or intercalary, monoclinous, occasionally diclinous, 12∼15 ${\times}$ 8∼11 um, 1(∼2) per oogonium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.161-170
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• 2008

Interest is growing in applying simulation models for the South Texas conditions, to better assess crop water use and production with different crop management practices. The Environmental Policy Integrated Climate (EPIC) model was used to evaluate its application as a decision support tool for irrigation management of com (Zea mays L.) in South Texas of the U.S. We measured actual crop evapotranspiration (ETc) using a weighing lysimeter, soil moisture using a neutron probe, and grain yield by field sampling. The model was then validated using the measured data. Simulated ETc using the Hargreaves-Samani equation was in agreement with the lysimeter measured ETc. Simulated soil moisture generally matched with the measured soil moisture. The EPIC model simulated the variability in grain yield with different irrigation regimes with $r^2$value of 0.69 and root mean square error of $0.5\;ton\;ha^{-1}$. Simulation results with farm data demonstrate that EPIC can be used as a decision support tool for com under irrigated conditions in South Texas. EPIC appears to be effective in making long term and pre-season decisions for irrigation management of crops, while reference ET and phenologically based crop coefficients can be used for inseason irrigation management.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.3
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• pp.353-359
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• 2012

The identification of effective root zone would clarify dynamics of plant available water and soil water balance. Using the relationship between soil properties and electrical resistivity (ER) the purpose of this research is to identify soil zone affected by a plant root activity using electrical resistivity tomography (ERT) technique. Four plastic containers were prepared for two different soil textures (clay and sandy loam) and one container for each texture was selected for planting four corn seedlings (Zea mays L.) and the others were prepared for the blank. For ERT monitoring, we prepared 0.8 m plastic sticks with 17 electrodes installed with 5 cm space. The Ministing (AGI Inc., Texas) instrument for electrical resistivity measurement and semi-auto converter of electrode arrangement were set up for dipole-dipole array. During 2 months of the corns growing, ERT monitoring was made 3 to 4 days after the irrigation practice. Despite of the same amount water supplied into soils, two textures showed very different apparent resistivity values due to different clay content. The apparent electrical resistivity is consistently lower in clay loam comparing to sandy loam soil implying that plant root does not significantly alter the overall trend of resistivity. When plant root system, however, is active both soils with plants showed 2-7 times higher electrical resistivity and higher coefficient variation than soils without plant, implying the effect of root system on the resistivity, in which may caused by. This result suggests plant root activities regulating the soil water dynamics mainly control the variation of electrical resistivity over soil textural difference. Therefore the identification of water uptake zone would highly be correlated to plant root activities, thus ERT will be feasible approach to identify spatial characteristics of a plant root activity.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.398-402
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• 1984

These experiments were conducted to investigate the substrate specificity, the hydrolysis products on the various carbohydrates and the hydrolysis rate on the various raw starches of the two purified glucoamylase produced by Rhizopus oryzae. Both of the glucoamylases hydrolyzed amylose, amylopectin, glycogen, soluble starch, pullulan, maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose and maltooctaose, but did not act on ${\alpha}-cyclodextrin$, ${\beta}-cyclodextrin$, raffinose, sucrose and lactose. When the reaction mixture of glucoamylase and polysaccharides were incubated $37^{\circ}C$for 32 hours, glucoamylase I hydrolyzed amylopectin, soluble starch and amyloses completely, but hydrolyzing glycogen up to only about 88%. Glucoamylase II hydrolyzed the previous four polysaccharides up to about 100%. Both of the glucoamylases produced only glucose for various substrates and did not have any ${\alpha}-glucosyl$ transferase activity. Both of the glucoamylases hydrolyzed raw glutinous rice starch almost complety, wheras they acted on raw potato starch, raw green banana starch, raw arrow root starch, raw corn starch, raw yam starch and raw high amylose corn starch weakly. Glucoamylase II hydrolyzed raw starches at the higher rate than glucoamylase I.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.3
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• pp.190-194
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• 2000

Double cropping is important for increase of farm income and rate of arable land utilization. This study was carried out to obtain information for optimum plant density of the second crop in a double cropping system. A waxy corn hybrid, Chalok #2, was sown on July 10 at the first corn cropping site. Growth characteristics and yield response of fresh waxy corn were examined under different planting densities, which were 55.5, 66.6, 83.3, and 111.1 thousands plants ${ha}^{-1}$. Plant height was higher under high planting density than low planting density and 154cm at the 55.5 thousand plants ${ha}^{-1}$, and 168cm at the 111.1 thousand plant ${ha}^{-1}$. It showed same trends in ear height and gravity center height. But planting density did not affect root lodging and silking date. At the silking stage, stalk and leaf dry matter weight and leaf area index (LAI) were increased significantly with increasing planting density, Filled ear lengtg was shortened significantly under the hi임est planting density (111.1 thousand plants ${ha}^{-1}$), while ear length and ear diameter were no differences among planting densities. The number of marketable ears increased with increasing planting density, but husked fresh ear weight was the highest at 83.3 thousand plants ${ha}^{-1}$ with 11.2MT ${ha}^{-1}$and optimum planting density was estimated as about 80 thousand plants ${ha}^{-1}$.