• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.35-41
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• 2006

This study was conducted to establish the post-harvest management system in rice. Harvested hulled rice was gathered into large-scale bag and combine bag, in which the rice quality and the influence on quality change were investigated on various storage periods and moisture contents. Moisture content of hulled rice ranged from 23.7% to 28.8% on different harvest times, which grew lower as harvesting time was delayed. When desiccation was retarded hulled rice in large scale bag was changed in color and emitted an of offensive odor in 3 days and that in combine bag showed similar symptom in 4 days. Inner temperature in large scale bag was changed a lot when the storage period was prolonged and also the moisture content was higher while that in combine bag increased regularly corresponding to the moisture content at the time of harvest. Moisture content of hulled rice stored in large-scale bag increased 2 days after harvest and the more moisture content showed the more increased tendency, while in the case of combine bag the moisture content was not changed much whether the hulled rice contained low or high moisture content in harvesting. As desiccation was delayed fatty acid increased much more in large-scale bag than in combine bag even though protein and amylose contentwere not changed. As desiccation was delayed more and hulled rice contained moisture more in harvesting head rice ratio of brown rice decreased and green-kerneled rice and damaged grain ratio increased and quality of milled rice also became deteriorated. As a result, desiccation day to minimize the deterioration of rice quality was estimated 1-2 days in large scale bag and 2-3 days in combine bag after harvesting.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.353-364
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• 2020

Recently in Korea, soybean harvesting has been delayed due to rainfall during the harvesting season, resulting in a reduction in yield and seed quality. This study was conducted to analyze the changes in yield and seed quality during delayed harvest with rainfall treatment using different harvesting methods, including field harvesting and polyethylene film covering after cutting fully-matured soybean plants (PE covering after cutting), with two major Korean soybean cultivars (Glycine max L), Pungsannamulkong and Daewonkong. The shattering rate of Pungsannamulkong, which is higher than that of Daewonkong, increased up to 41.8% when the harvest was delayed for 40 days without rainfall treatment by harvesting with PE covering after cutting. The weight of 100 seeds tended to decrease slightly as harvesting was delayed. When Daewonkong was harvested using the PE covering after cutting method with rainfall treatment, the yield decreased to the lowest level with a 0.8 kg ha^-1 daily reduction rate. Pungsannamulkong showed the lowest yield when harvested using PE covering after cutting without rainfall treatment with a 3.4 kg ha^-1 daily reduction rate. The infected seed rate increased according to the harvest delay in both cultivars, and significant differences were observed according to rainfall treatment and harvesting method. The germination rate was maintained above 95% even after 40 days of delayed harvest if there was no rainfall treatment. However, with rainfall treatment, the germination rate was significantly lowered as harvesting time was delayed. In the field harvesting with rainfall treatment, the germination rate decreased to 77.2% for Daewonkong and 76.5% for Pungsannamulkong after 40 days of harvest delay. For the 100-seed weight, effects of individual treatments and interactions between treatments were not observed. In contrast, the effect of interactions between treatments on the shattering rate was significant in both cultivars, indicating that the shattering rate had the greatest impact on the yield changes during delayed harvest.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.255-263
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• 2010

Inclusion body hepatitis-hydropericardium syndrome (IBH-HPS) is an acute viral disease usually found in broilers aged from 3 to 5 weeks and causes up to 75% mortality. Among the 12 serotypes of fowl adenovirus group 1, serotype-4 (FAdV-4) was identified as a primary agent of IBH-HPS and was usually isolated in IBH-HPS cases in Korea since 2007. To prevent these IBH-HPS outbreaks in Korea, we developed the FAdV-4 inactivated vaccine using Korean isolate (ADL070244) and evaluated the efficacy of this vaccine. For the efficacy test, 2-week-old specific-pathogen-free (SPF) chickens intramuscularly inoculated with 1 or 2 dose of inactivated vaccine were used and challenged with FAdV-4 through either intramuscular or oral route at 2 weeks after vaccination. The vaccine induced good seroconversion which was confirmed by agar gel precipitation (AGP) test. In addition, the vaccine could decrease the FAdV-4 detection rate and histological lesion severity such as lymphocyte infiltration and necrosis in the liver comparing with those of non-vaccination group. Based on the current results, the developed FAdV-4 inactivated vaccine in this study was effective in the terms of reduction of virus detection rate and histological lesions severity. However, it was difficult to confirm the efficacy of the vaccine clearly because of no mortality and clinical signs in the non-vaccinated group after challenge. Therefore, we need further study to develop a standard challenged model system which could clearly evaluate the efficacy of the vaccines for FAdV-4.

• Journal of Korea Water Resources Association
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• v.45 no.8
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• pp.795-804
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• 2012

Recently, changes in rainfall intensity and patterns have been causing increasing soil loss worldwide. As a result, the water ecosystem becomes worse and crops yield are reduced with soil loss and nutrient loss with it. Many studies have been proposed to estimate runoff and soil loss to predict or decrease non-point source pollution. Although the USLE has been used for many years in estimating soil losses, the USLE cannot reflect effects on soil loss of changes in rainfall intensity and patterns. The WEPP, physically based model, is capable of predicting soil loss and runoff using various rainfall intensity. In this study, the WEPP model was simulated for sediment yield, runoff and peak runoff using data of 5, 10, 30, 60 minute term rainfall, Huff's method and design rainfall. In case of rainfall interval of 5 minutes and 60 minutes, the sediment and runoff values decreased by 24% and 19%, respectively. The peak rate runoff values decreased by 16% when rainfall interval changed from 5 minutes to 60 minutes, indicating the peak rate runoff values are affected by rainfall intensity to some degrees. As a result of simulating using Huff's method, all values (sediment yield, runoff, peak runoff) were found to be the greatest at third quartile. According to the analysis under various design rainfall conditions (2, 3, 5, 10, 20, 30, 50, 100, 200, 300 years frequency), sediment yield, runoff, and peak runoff of 906.2%, 249.4% and 183.9% were estimated using 2 year to 300 year frequency rainfall data.

• Journal of Korea Water Resources Association
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• v.40 no.9
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• pp.697-707
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• 2007

In this study, we estimated the PMP(Probable Maximum Precipitation) and its transition in case of the typhoon Rusa which happened the biggest damage of all typhoons in the Korea. Specially, we analysed the moisture maximizing rate under the consideration of meteorological condition based on the orographic property when it hits in Gangneung region. The PMP is calculated by the rate of the maximum persisting 12 hours 1000 hPa dew points and representative persisting 12 hours 1000 hPa dew point. The former is influenced by the moisture inflow regions. These regions are determined by the surface wind direction, 850 hPa moisture flux and streamline, which are the critically different aspects compared to that of previous study. The latter is calculated using statistics program (FARD2002) provided by NIDP(National Institute for Disaster Prevention). In this program, the dew point is calculated by reappearance period 50-year frequency analysis from 5% of the level of significant when probability distribution type is applied extreme type I (Gumbel distribution) and parameter estimation method is used the Moment method. So this study indicated for small basin$(3.76km^2)$ the difference the PMP through new method and through existing result of established storm transposition and DAD(Depth-Area-Duration). Consequently, the moisture maximizing rate is calculated in the moisture inflow regions determined by meteorological fields is higher $0.20{\sim}0.40$ range than that of previous study. And the precipitation is increased $16{\sim}31%$ when this rate is applied for calculation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.136-143
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• 2019

This study investigated the effects of environmental temperature and humidity on the physiological indicators such as respiratory rate, rectal temperature, and rumination time in cows. Twenty lactating Holstein cows were used for this study. The temperature/humidity index, which can be measured by the temperature and humidity of barns, was divided into three stages to distinguish the heat stress level of cows. The temperature and humidity indexes of each stage were classified into 70 ~ 75 for T1, 76 ~ 81 for T2, and 82 ~ 87 for T3, respectively. The respiratory rates per minute were 58.60 at T1, 66.12 at T2, and 84.05 at T3, respectively (P < 0.05), and the average rectal temperatures (℃) of the cows were 38.41 in T1, 38.69 in T2 and 39.05 in T3, respectively (P < 0.05). The body surface temperatures (℃) were 36.41 in T1, 36.51 in T2, and 37.39 in T3, respectively. The rumination times (minutes/day) were 473.10 in T1, 454.76 in T2, and 399.60 in T3, respectively (P < 0.05). As global warming continues to damage the dairy industry, further research is needed to improve the welfare of dairy cows and reduce their heat stress.

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.428-439
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• 2015

Pepper anthracnose caused by Collectotrichum acutaum has been known as one of the most damaging diseases of pepper, which has reduced not only yield but also quality of pepper produce almost every year. This study was conducted to develop control strategy against pepper anthracnose by alternate application of agricultural organic materials and chemical fungicides. The alternate application effect of agricultural organic materials and chemical fungicides for controlling pepper anthracnose were examined in vitro and in the field. First, thirteen microbial agents and twenty two agricultural organic materials were screened for antifungal activity against C. acutatum through the dual culture method and bioassay. As a result, one microbial agent (Bacillus subtilis QST-713) and three agricultural organic materials (sulfur, bordeaux mixture, marine algae extracts) were found to show high inhibition effect against C. acutatum. In the field test, when Iminoctadine tris+thiram, a chemical fungicide for controlling pepper anthracnose, was sprayed, it reduced disease incidence by 89.5%. Meanwhile Sulfur, bordeaux mixture, copper, marine algae extracts and Bacillus subtilis QST-713 showed low disease incidence at the range of 33.1~81.0%. However, when Iminoctadine tris+thiram and agricultural organic materials(bordeaux mixture, marine algae extracts) were applied to pepper fruits alternately two times at 7 days interval, there was a 81.7 and 87.1% reduction in disease, respectively. Consequently, the alternate spray of chemical fungicide (Iminoctadine tris+thiram) and agricultural organic materials (bordeaux mixture, marine algae extracts) could be recommended as a control method to reduce the using amount of chemical fungicide.

• Journal of the Korean Wood Science and Technology
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• v.46 no.1
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• pp.73-84
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• 2018

Recently, the importance of flame retardation treatment technology has been emphasized due to the increase in urban fire accidents and fire damage incidents caused by building exterior materials. Particularly, in the utilization of wood-based building materials, the flame retarding treatment technology is more importantly evaluated. An Intumescent system is one of the non-halogen flame retardant treatment technologies and is a system that realizes flame retardancy through foaming and carbonization layer formation. To apply the Intumescent system, composite material was prepared by using Ethylene vinyl acetate (EVA) as a matrix. To enhance the flame retardant properties of the Intumescent system, a nano-clay was applied together. Composite materials with Intumescent system and nano - clay technology were processed into sheet - like test specimens, and then a new structure of cross laminated timber with improved flame retardant properties was fabricated. In the evaluation of combustion characteristics of composite materials using Intumescent system, it was confirmed that the maximum heat emission was reduced efficiently. Depending on the structure attached to the surface, the CLT had two stages of combustion. Also, it was confirmed that the maximum calorific value decreased significantly during the deep burning process. These characteristics are expected to have a delayed combustion diffusion effect in the combustion process of CLT. In order to improve the performance, the flame retardation treatment technique for the surface veneer and the optimization technique of the application of the composite material are required. It is expected that it will be possible to develop a CLT structure with improved fire characteristics.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.123-158
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• 2009

An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.253-261
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• 2009

For the environment-friendly control of beet armyworm, Spodoptera exigua, in spring onion fields, we have examined an alternative application method. Twenty-five insecticides registered for spring onion were tested for control effect against the beet armyworm in the laboratory, then the best 9 chemical and a single biological insecticides were selected and compared with 2 new isolates of Bacillus thuringiensis in a polyvinyl house. After that, 4 chemical and 3 B. thuringiensis treatments were used in the field for the control of beet armyworm in the spring onion. Two application methods are used: one is triple treatments with the same chemical and the other is alternative application with different chemicals and B. thuringiensis for 7 days intervals. Indoxacarb WP - chlorfluazuron EC - B.t. var. kurstaki CAB141 and indoxacarb WP - methoxyfenozide + spinosad SC - Chlorfluazuron EC - B.t. var. aizawai CAB109, B.t. var. kurstaki CAB141 showed greater than 78% mortality of beet armyworm larvae and greater than 43% damage decrease in spring onions infested by beet armyworm. These results showed that alternative applications had higher control effect than any other applications. It was suggested that alternative applications with microbial biological agents such as B. thuringiensis might minimize the development of insecticide resistance and might be used as the environment-friendly control of the beet armyworm.