• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.435-441
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• 2017

The present study was carried out to evaluate the applicability of Tenebrio molitor larvae (mealworm) as a health functional food material in order to contribute to the development of the domestic insect industry and health functional food industry. Protein hydrolysates were prepared from mealworm powder by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain), and the hydrolysates were then tested for their antioxidant activities. Based on available amino group contents and sodium dodecyl sulphate-polyacrylamide gel electrophoresis analyses, mealworms treated with alcalase ($4,781.39{\mu}g/mL$), flavourzyme ($5,429.35{\mu}g/mL$), or neutrase ($3,155.55{\mu}g/mL$) for 24 h showed high degree of hydrolysis (HD) value, whereas HD values of bromelain ($1,800{\mu}g/mL$) and papain-treated ($1,782.61{\mu}g/mL$) mealworms were much lower. Protein hydrolysates showing high HD values were further separated into > 3 kDa and ${\leq}3kDa$ fractions by a centrifugal filter system and then lyophilized, and the production yields of the low molecular weight protein hydrolysates (${\leq}3kDa$) by alcalase, flavourzyme, and neutrase were 42.05%, 26.27%, and 30.01%, respectively. According to the RC_{50} values of the protein hydrolysates (${\leq}3kDa$) obtained from three different antioxidant analyses, all three hydrolysates showed similar antioxidant activities. Thus, alcalase hydrolysates showing the highest production yield of low molecular weight protein hydrolysates were further tested for their inhibitory effects on peroxidation of linoleic acid by measuring thiobarbituric acid values, and the results show that peroxidation of untreated linoleic acid increased dramatically during 6 days of incubation. However, pretreatment with the hydrolysates ($100{\sim}800{\mu}g/mL$) significantly inhibited linoleic acid peroxidation in a dose-dependent manner over 6 days.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.322-326
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• 2012

Recently, researches related to plant factory system has been activated and production of Ssam-vegetables using artificial lighting has been increasing. In South Korea, Ssam-vegetables are very popular and the consumption is increasing every year. Because leaf vegetables cultivated under hydroponic systems are more preferable rather than those cultivated by soil culture in Korea, the plant factory system would be more effective in production of Ssam-vegetables. Therefore, this study was carried out in order to analyze the yield and vitamin C contents in red mustard (Brassica juncea L.) and pak-choi (Brassica campestris var. chinensis), which are used a lot for the Ssam-vegetables in South Korea, as influenced by different concentrations of the nutrient solution in a plant factory system. As a results, there was no significant differences in the plant height among the treatment of EC in the nutrient solution, but for red mustard plants, the number of leaves tended to decrease in the treatment with higher EC. Leaf area of pak-choi plants was significantly increased in the higher EC, while the fresh weight had a tendency to increase along with increasing EC in the nutrient solution for both crops. The photosynthetic rates did not show a distinct tendency by EC levels for red mustard plants, but for pak-choi plants, it tended to be higher at the high EC. The contents of ascorbic acid in leaves were higher with decreasing EC concentration in the nutrient solution for red mustard plants, while the content was the highest at EC $2.0dS{\cdot}m^{-1}$ for pak-choi plants. In summary, considering the marketable yields and vitamin C at different nutrient concentrations in a plant factory, the optimal concentration for red mustard and pak-choi plants was thought to be EC $2.0{\sim}2.5dS{\cdot}m^{-1}$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.1
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• pp.97-124
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• 1976

To find out the most effective method of treatments for the induction of sprouting of dormant seed potato pieces for the fall crop production of Irish cobbler, this experiment was carried out with sprout inducing bed and field performance trial. In GA treatments, about 10 days were required to sprout and resulted uniform and thin 3-4 sprouts per tuber piece, but sprouts were slender and rooting was not observed. In Ethrel treatments, 20-25 days were required, and sprouts were inferior than that of GA treatment in uniformity of sprouting, and percentage of rotten pieces and of healthy sprouted tuber pieces, but number of sprouts per tuber pieces was low, being 1-2, and sprouts were short, thick, and healthy, and showed good rooting. In GA and Ethrel mixture treatments, 1-2 more days were required to sprout than GA treatments, but sprouts were relatively healthy, and other sprouting pattern were like that of GA treatments. In Ethylene chlorohydrin and 6-Benzyl-adenine treatments, sprouting was like that of Ethrel treatments, but much more days were required than Ethrel treatments and tendency of severe rotting was observed. Optimum treating methods of promising chemicals found to be 1-2 and 2-5 ppm GA solution, 500 and 1000-2000 ppm Ethrel solution, and 1-2＋250-500 and 5＋250-500 ppm GA and Ethrel mixture solution for 60 min. treatment of tuber piece and whole-tuber, respectively. Induction of sprouting in dry and hot time resulted severer rotting of tuber pieces during the induction of sprouting and with the advancement of dormancy, being delayed in date of treatment, tendency of promotion of sprouting and rooting was observed. When sprouted tuber piece was transplanted at the same date, yields were in order of Ethrel, GA and Ethrel mixture, and GA treatment, indicating the correlation between yield and healthiness of sprout and rooting status of sprouted tuber piece. In all treatments, earlier transplanting resulted higher yields.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.6
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• pp.111-121
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• 2019

Evapotranspiration (ET) of vegetation is one of the major components of the hydrologic cycle, and its accurate estimation is important for hydrologic water balance, irrigation management, crop yield simulation, and water resources planning and management. For agricultural crops, ET is often calculated in terms of a short or tall crop reference, such as well-watered, clipped grass (reference crop evapotranspiration, $ET_o$). The Penman-Monteith equation recommended by FAO (FAO 56-PM) has been accepted by researchers and practitioners, as the sole $ET_o$ method. However, its accuracy is contingent on high quality measurements of four meteorological variables, and its use has been limited by incomplete and/or inaccurate input data. Therefore, this study evaluated the applicability of Backpropagation Neural Network (BPNN) model for estimating $ET_o$ from less meteorological data than required by the FAO 56-PM. A total of six meteorological inputs, minimum temperature, average temperature, maximum temperature, relative humidity, wind speed and solar radiation, were divided into a series of input groups (a combination of one, two, three, four, five and six variables) and each combination of different meteorological dataset was evaluated for its level of accuracy in estimating $ET_o$. The overall findings of this study indicated that $ET_o$ could be reasonably estimated using less than all six meteorological data using BPNN. In addition, it was shown that the proper choice of neural network architecture could not only minimize the computational error, but also maximize the relationship between dependent and independent variables. The findings of this study would be of use in instances where data availability and/or accuracy are limited.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.2
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• pp.19-30
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• 2019

Objective of this study was to develop an organic fertilizer utilizing domestic livestock horn meal and to investigate the application effect of rice and eggplant. The possibility of utilization of livestock horn meal as an organic resource to replace imported expeller cake fertilizer was examined. In order to select domestic organic resources with high nitrogen content, 8 kinds of organic matter such as chicken manure, fish meal, soybean meal, sesame meal, perilla meal, blood meal, livestock horn meal, and beer sludge were analyzed and organic resources with high nitrogen content were selected. In addition, the conditions for the production of organic fertilizers that can be used in organic agriculture were established by mixing of the rice husk biochar and the rice bran as the supplements with the raw materials for mixing ratios. The content of total nitrogen (T-N) in the livestock horn meal was 12.0 %, which was the next low in 13.5 % blood meal. The content of total nitrogen was 5.9 ~ 7.9 % in fish meal and oil cakes. Total nitrogen content of non-antibiotic chicken manure for organic farming was 3 % and nitrogen content in beer sludge was 3.5 %. Organic fertilizer was produced by using biochar, rice bran as a main ingredient of non-antibiotic chicken manure, livestock horn meal and beer sludge. Compared to nitrogen content (4.0 to 4.2 %) of imported expeller cake fertilizer (ECF), the nitrogen content of organic fertilizer utilizing domestic livestock horn meal is as high as 7.5 %. The developed organic fertilizer is met as Zn 400 mg/kg, Cu 120 mg/kg the quality of organic agricultural materials such as or less. To investigate the effect of fertilizer application on the crops, prototypes of developed organic fertilizer were used for the experiment under selected conditions. As a result of application the developed organic livestock horn meal fertilizer (LHMF) for cultivation of the rice and eggplant, the application quantity of the developed organic LHMF 100 % was decreased by 40 % compared to that of the mixed expeller cake fertilizer (MECF). The application of LHMF, which refers to the application rate corresponding to the nitrogen fertilization recommended by the soil test, was reduced by 40% compared to the application rate of MECF, but the same results were obtained in crop growth and yield. The selection of a new high concentration nitrogen source utilizing domestic organic resources and the development of organic fertilizer is the starting point of the research for substitution of imported ECF using domestic local resources at the present time that the spread of eco-friendly agriculture is becoming increasingly important. If it is expanded in the future, it is expected to contribute to the stable production of eco-friendly agricultural products.

• Journal of Bio-Environment Control
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• v.28 no.3
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• pp.185-196
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• 2019

Abstract. This research was conducted to figure out the optimal size of the plug cell and seedling raising period in 'Nongwoo' and 'Nonghyeop' cultivars. In the first experiment on effect of plug cell size on growth of squash, seedlings were transplanted into hydroponic cultivation beds at different growing stages: Those in 32-cell trays with 3-4 true leaves at 25 days after sowing, those in 50-cell trays with 2 true leaves at 15 days after sowing, those in 105-cell trays just before a true leaf development, and those in 162-cell trays with only cotyledons at 8 days after sowing. In the second experiment on effect of seedling raising period on growth of squash, it was conducted to have different sowing dates. But the same transplanting date, based on the results of Experiment 1, and compared the differences in growth and fruit productivity as affected by plug cell size in the same way with experiment 1 including the cultivars and environmental conditions. After setting the transplanting date in advance, the number of days for sowing were calculated back for each treatment. In the first experiment, plant height was the greatest in 105-cell trays followed by 162, 50 and 32-cell trays in both cultivars. The best fruit quality was found in different treatments depending on the cultivars, although it was the lowest in 32-cell trays in both cultivars. The fruit quality was not significantly different among those from cell sizes. Therefore, when raising seedlings in 105-cell trays, the period of raising seedlings can be shortened as compared with the conventional 32-cell trays, and this change could reduce the workforce required for growing and transplanting seedlings. In the second experiment, after transplanting, shoot height and leaf width in the first measurement in both cultivars were greater in the 32-cell treatment. However, the last measurement after four weeks showed no significant difference in plant height, but significantly greatest leaf width in the smallest cell treatment, even as compared with that in 32-cell treatment. In case of 'Nongwoo', length and weight of the first harvested fruit showed the highest values in the treatment of 105-cell trays. In case of 'Nonghyeop' the 162-cell treatment along with the 105-cell treatment showed greatest length and weight of the first fruits. From these results, zucchini plug seedlings can be raised in plug trays with reduced cell sizes than the conventional 32-cell trays with improved fruit productivity.

• Journal of Plant Biotechnology
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• v.46 no.3
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• pp.228-235
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• 2019

Apple (Malus pumila) is one of the most economically important fruits in Korea. but virus infection has decreased the sustainable production of apples and caused serious problems such as yield loss and poor fruit quality. Virus or viroid infection including apple chlorotic leaf spot virus (ACLSV), apple stem pitting virus (ASPV), apple stem grooving virus (ASGV), apple mosaic virus (ApMV) and apple scar skin viroid (ASSVd) have been also reported in Korea. In many cases, as apple gets infected with virus and viroid with no specific symptoms, the damage and symptoms caused by the viruses are not detected. In our research, viruses in the rootstock were eliminated for a virus-free apple dwarfing rootstock of M.9 and M.26. The virus elimination methods were apical meristem culture, thermotherapy ($37^{\circ}C$, 6 weeks) and chemotherapy($Ribavirin^{(R)}$). The detection of apple viruses was accomplished by Enzyme-linked Immuno-Sorbent Assay (ELlSA) and reverse transcription-polymerase chain reaction (RT-PCR). RT- PCR method was 10 ~ 30% more sensitive than the ELISA method. The efficiency of virus elimination was enhanced in apical meristem culture method. The acquisition rate of virus-free apple dwarfing rootstocks was 30 ~ 40% higher in apical meristem culture. After the meristem culturing of M.9, the infection ratio of ACLSV, ASPV and ASGV was 45%, 60% and 50%, respectively. In the apple dwarfing rootstock of M.26, the infection ratio of ACLSV, ASPV and ASGV was 40%, 55% and 55%, respectively. Based on this study, the best method for the production of virus-free apple dwarfing rootstocks was the apical meristem culture.

• Korean Journal of Environmental Agriculture
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• v.38 no.3
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• pp.166-172
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• 2019

BACKGROUND: Increase in the ratio of small berries in blueberry production decreases the farmers' profits due to weakening market competitiveness and lowering harvest efficiency. One of the reasons for increased small berries is over fruit-load. For improving productivity and competitiveness of blueberry in Korea, hand-thinning can be applied to increase fruit quality before the developing adequate chemical thinning methods. This study was conducted to investigate the proper timing and methods for floral buds thinning in rabbiteye blueberry. METHODS AND RESULTS: Eight years old bushes of rabbiteye bluberries 'Brightwell' as a primary cultivar and 'Powderblue' as a pollinizer were used for this study. Fruit size distribution by leaf-to-fruit ratio was investigated by counting the number of leaves and fruits in canes of 127 'Brightwell' plants whose fruit set varied. Fifty percent of flowers/floral buds were removed in four different floral buds stages such as bud swell, late pink bud, full bloom, and petal fall, and the consumed time for thinning and fruit characteristics were recorded to investigate the effect and proper timing of floral buds thinning. Fruit weight and soluble solids content tended to increase in proportion to leaf-to-fruit ratio and the production of the number of fruits less than 13 mm in diameter decreased when leaf-to-fruit ratio was more than 2.5. Manual floral buds thinning by hands was fastest in full bloom stage and slowest in bud swelling stage. In all cultivars, fruit size was significantly smaller in non-thinning treatment than thinning, and there was, however, no significant difference in total fruit yield. The number of fruits less than 13 mm in diameter increased in both cultivars as floral buds thinning was delayed. Consumed time for picking 90% berries out of total berries per bush was shortest in full bloom stage thinning in 'Brightwell' and bud swelling, full bloom thinning in 'Powderblue'. These were 25 and 20 days faster than no thinning, respectively. CONCLUSION: Although the effect of floral buds thinning varied depending on the cultivars, our results confirmed that floral buds thinning was effective for the early intensive harvesting and the increase of the large fruit ratio and the harvesting productivity. Also, in order to increase thinning efficiency, it is recommended to remove the flower buds before the full bloom stage.

• Journal of Environmental Impact Assessment
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• v.30 no.2
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• pp.117-131
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• 2021

Urban development is continuously being carried out to stabilize housing supply. The importance of ecosystem services assessments considering the various urban spatial structures is emerging as land use change in the wake of urban development has impact on the provision of ecosystem services. However, few studies are available as to the effects of land use transition in agricultural land due to urban development on ecosystem services. The purpose of this study is to examine the applicability of decision-making in the urban planning process by analyzing the impact of land use change on ecosystem services due to urban development. Therefore, the scenario was set on before and after the city development, targeting Namyangju Wangsuk Zone 1 and InVEST model was used to compare and analyze changes in value of ecosystem services. Analysis results of ecosystem services before the urban development, it turned out that habitat quality and water yield increased overtime but carbon storage and crop production decreased. Analysis results of ecosystem services after the urban development indicated that all items in ecosystem services by scenario decreased more than in 2018. Among the scenarios of urban development, compact city had the lowest value of water resource supply but had the highest value in terms of habitat quality, carbon storage amount, and crop production. The study results demonstrate that the compact city has positive effects on ecosystem services and is expected to be used as the basic data for supporting policy decision-making in the establishment of future urban development and management plans.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.235-250
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• 2021

The overarching question of this study is how a typical rice cultivation system in Gimje, Korea was keeping up with the triple-win challenge of climate-smart agriculture (CSA). To answer this question, we have employed (1) quantitative data from direct measurement of energy, water, carbon and information flows in and out of a rice cultivation system and (2) appropriate metrics to assess production, efficiency, GHG fluxes, and resilience. The study site was one of the Korean Network of Flux measurement (KoFlux) sites (i.e., GRK) located at Gimje, Korea, managed by National Academy of Agricultural Science, Rural Development Administration. Fluxes of energy, water, carbon dioxide (CO₂) and methane (CH₄) were directly measured using eddy-covariance technique during the growing seasons of 2011, 2012 and 2014. The production indicators include gross primary productivity (GPP), grain yield, light use efficiency (LUE), water use efficiency (WUE), and carbon uptake efficiency (CUE). The GHG mitigation was assessed with indicators such as fluxes of carbon dioxide (F_CO2), methane (F_CH4), and nitrous oxide (F_N2O). Resilience was assessed in terms of self-organization (S), using information-theoretic approach. Overall, the results demonstrated that the rice cultivation system at GRK was climate-smart in 2011 in a relative sense but failed to maintain in the following years. Resilience was high and changed little for three year. However, the apparent competing goals or trade-offs between productivity and GHG mitigation were found within individual years as well as between the years, causing difficulties in achieving the triple-win scenario. The pursuit of CSA requires for stakeholders to prioritize their goals (i.e., governance) and to practice opportune interventions (i.e., management) based on the feedback from real-time assessment of the CSA indicators (i.e., monitoring) - i.e., a purpose-driven visioneering.