• Journal of Agricultural Extension & Community Development
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• v.22 no.4
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• pp.423-434
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• 2015

This paper predicts the onion's cultivation areas, yields per unit area, and wholesale prices during ship dates by using wholesale price data from the Korea Agro-Fisheries & Food Trade Corporation, the production data from the Statistics Korea, and the weather data from the Korea Meteorological Administration with an ARDL model. By analyzing the data of wholesale price, rural household income and rural total earnings, onion cultivation areas in 2015 are estimated to be 21,035, 17,774 and 20,557(ha). In addition, onion yields per unit area of South Jeolla Province, North Gyeongsang Province, South Gyeongsang Province, Jeju Island, and the whole country in 2015 are estimated to be 5,980, 6,493, 6,543, 6,614, 6,139 (kg/10a) respectively. By using onion production's predictive value found from onion's cultivation areas and yields per unit area in 2015, the onion's wholesale prices in June are estimated to be 780 won, 1,100 won, and 820 won for each model. Predicted monthly price after the onion's ship dates is analyzed to exceed 1,000 won after August.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.687-692
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• 1998

To use onion(Allium cepa L.) residue as raw materials of food product, yields of onion-juice according to various extracting methods and optimal extracting condition of quercetin and its related glycosides were carried out. Onion juices gained by the methods of pressing, rotary crushing, freeze pressing and enzyme treatment. The yield by the method of enzyme treatment was higher than others. The yields of juice from fresh onion and heat-treated onion(8$0^{\circ}C$/10min) by pressing were 66% and 83%, respectively. Ethanol extraction of onion was efficient at 75$^{\circ}C$ and acetic acid extraction was proper at 3% concentration for 3 hours at 11$0^{\circ}C$. The onion extract was fractionated in the order of hexane, chloroform, ethylacetate and butanol to test flavonoids. The highest abundant flavonoids were found in ethylacetate and butanol fraction.

• The Korean Journal of Applied Statistics
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• v.29 no.5
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• pp.873-885
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• 2016

Onions are grown in a few specific regions of Korea that depend on the climate and the regional characteristic of the production area. Therefore, when onion yields are to be estimated, it is reasonable to use a statistical model in which both the climate and the region are considered simultaneously. In this paper, using a spatial panel regression model, we predicted onion yields with the different weather conditions of the regions. We used the spatial auto regressive (SAR) model that reflects the spatial lag, and panel data of several climate variables for 13 main onion production areas from 2006 to 2015. The spatial weight matrix was considered for the model by the threshold value method and the nearest neighbor method, respectively. Autocorrelation was detected to be significant for the best fitted model using the nearest neighbor method. The random effects model was chosen by the Hausman test, and the significant climate variables of the model were the cumulative duration time of sunshine (January), the average relative humidity (April), the average minimum temperature (June), and the cumulative precipitation (November).

• Microbiology and Biotechnology Letters
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• v.27 no.1
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• pp.75-79
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• 1999

Various conditions for onion-juice production, and for alcohol and acetic acid fermemtations were investigated to produce a vinegar from onion. In the production of the onion juice, treatments with enzymes such as 0.6% Celluclast 1.5L and 0.2% Viscozyme L increased the yields significantly from 45.0% to 54.5% and 72.5%, respectively. Alcohol and acetic acid fermentations from the onion juice were effectively improved by using the onion juice heated at 80$^{\circ}C$ for 10 minutes, and by adding 0.3% yeast extract, 0.3% $MgSO_4$ and 0.3% $K_3PO_4$ as nutrients to the onion juice. At the optimum condition, 5.8% alcohol was produced after five days of fermentation at $30^{\circ}C$ from the 14 Brix onion juice, which was adjusted by adding sugar. A vinegar with 6.7% acetic acid content was produced after 20 days of fermentation of $30^{\circ}C$ from 4% alcohol that was adjusted by adding onion juice.

• The Journal of Industrial Distribution & Business
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• v.11 no.3
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• pp.39-50
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• 2020

Purpose: Agriculture, which is heavily influenced by climate conditions, is one of the industries most affected by climate change. In this respect, various studies on the impact of climate change on the agricultural market have been conducted. Since climate change is a long-term phenomenon for more than a decade, long-term projections of agricultural prices as well as climate variables are needed to properly analyze the impact of climate change on the agricultural market. However, these long-term price projections are often major constraints on studies of climate changes. The purpose of this study is to analyze the impacts of climate changes on the Korean onion market using ex-post analysis approach in order to avoid the difficulties of long-term price projections. Research design, data and methodology: This study develops an annual dynamic partial equilibrium model of Korean onion market. The behavioral equations of the model were estimated by OLS based on the annual data from 1988 to 2018. The modelling system is first simulated to have actual onion market conditions from 2014 to 2018 as a baseline and then compared it to the scenario assuming the climatic conditions under RCP8.5 over the same period. Scenario analyses were simulated by both comparative static and dynamic approach to evaluate the differences between the two approaches. Results: According to the empirical results, if the climate conditions under RCP8.5 were applied from 2014 to 2018, the yield of onion would increase by about 4%, and the price of onion would decrease from 3.7% to 17.4%. In addition, the average price fluctuation rate over the five years under RCP8.5 climate conditions is 56%, which is more volatile than 46% under actual climate conditions. Empirical results also show that the price decreases have been alleviated in dynamic model compared with comparative static model. Conclusions: Empirical results show that climate change is expected to increase onion yields and reduce onion prices. Therefore, the appropriate countermeasures against climate change in Korean onion market should be found in the stabilization of supply and demand for price stabilization rather than technical aspects such as the development of new varieties to increase productivity.

• Korean Journal of Remote Sensing
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• v.33 no.5_2
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• pp.647-659
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• 2017

Garlic and onion are grown in major cultivation regions that depend on the crop condition and the meteorology of the production area. Therefore, when yields are to be predicted, it is reasonable to use a statistical model in which both the crop and the meteorological elements are considered. In this paper, using a multiple linear regression model, we predicted garlic and onion yields in major cultivation regions. We used the MODIS NDVI that reflects the crop conditions, and six meteorological elements for 7 major cultivation regions from 2006 to 2015. The multiple linear regression models were suggested by using stepwise regression in the extraction of independent variables. As a result, the MODIS NDVI in February was chosen the significant independent variable of the garlic and onion yield prediction model. In the case of meteorological elements, the garlic yield prediction model were the mean temperature (March), the rainfall (November, March), the relative humidity (April), and the duration time of sunshine (April, May). Also, the rainfall (November), the duration time of sunshine (January), the relative humidity (April), and the minimum temperature (June) were chosen among the variables as the significant meteorological elements of the onion yield prediction model. MODIS NDVI and meteorological elements in the model explain 84.4%, 75.9% of the garlic and onion with a root mean square error (RMSE) of 42.57 kg/10a, 340.29 kg/10a. These lead to the result that the characteristics of variations in garlic and onion growth according to MODIS NDVI and other meteorological elements were well reflected in the model.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.431-435
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• 2007

Control thresholds for the management of beet army worm, Spodoptera exigua (Lepidoptera : Noctuidae) were evaluated on welsh onion of two different planting time. Two inoculation times were tested for each planting and the number of inoculated larva was 5, 10, 20, 40 per twenty plants. The injured rate of leaves was 33.5% to 10.9% at 7th September at 40 to 5 larva inoculation plot on the five days planting. That of leaves was 20.5% at 40 larva on the twenty days planting. The yields of welsh onion on non-inoculation plot were 4,395 kg per 10a. The rate of reduced yields was 49.2%(1,774.2 kg) and 36.5%(2,220.5 kg) at 40 larva inoculation on the 5 and 20 days planting, respectively. The linear relationships between population density and yield reduction were as following; it was Y=-43.474X + 3419.6 ($R^2\;=\;0.9698$) for 5 days and Y=-32.977X + 3518.9 ($R^2\;=\;0.9928$) for 20 days. Based on these results the control threshold level was estimated to be 1.8 larva for 5 days and 4.6 larva for 20 days per 20 plant. The more damaged leaves by S. exigua larva, the more yield reduction on welsh onion.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.123-128
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• 2012

A two year study was conducted on the effects of composted pig manure applications on organically managed intermediate-day onion ($Allium$ $cepa$ L.) with mid-season production. The manure application rates were 0, 4.0, 6.0, and 8.0 $ton{\cdot}ha^{-1}$, and accompanied by organic fertilizer with 240 $kg{\cdot}ha^{-1}$ nitrogen for all treatments. There was a positive linear effect on the marketable bulb yield with increasing applications of pig manure. However, pig manure rates of 6.0 or 8.0 $ton{\cdot}ha^{-1}$ did not affect the marketable yields or bulb weights at harvest. There was no significant difference between pig manure application rates and mineral concentration or nutrient uptake in onion bulbs. Soil pH and electric conductivity (EC) were lower at harvest compared to preplant soil, while exchangeable potassium and calcium contents increased at harvest. However, there were no significant effects on soil pH, EC, and organic matter or exchangeable cations caused by different pig manure application rates. Mineralized $NO_3$-N content was not affected by pig manure application rates except at transplanting and 129 day after transplanting. Based on the results of this study, when organic fertilizer is applied at a rate of 240 $kg{\cdot}ha^{-1}$ N, 6.0 $ton{\cdot}ha^{-1}$ composted pig manure should be adequate for producing onions using an organic production system.

• Research in Plant Disease
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• v.7 no.1
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• pp.42-48
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• 2001

The effect of cultural, physical and chemical control methods on the population density of Meloidogyne arenaria second-stage juveniles (J2) and on fruit yields of oriental melon was investigated at Seongju Fruit Vegetable Experiments Station, Kyungpook province, Korea, for two years from 1999 to 2000. Crops used in a rotation prior to Oriental melon were rice, corn, sesame, and green onion. The physical methods used were either solarization, soil addition or soil drying, and a nematicide, fosthiazate of granular formula, was used as the chemical method, applying at a rate of 300g a. i./10 a. Growing rice in the rotation, solarization, and soil addition controlled the nematode disease most effectively, reducing the number of J2 by 90% and increasing fruit yields two times. However, the effects of these control methods on the J2 population were limited to the early growing season; the J2 population increased later, suggesting that additional control practices may be needed in the following season. The next effective control methods were use of corn in the rotation, the nematicide application, and soil drying. The nematicide application was effective only for the early fruit yield, but neither for the late nor for the total yields. Use of sesame or green onion in the rotation was not effective in controlling the nematode.

• Research in Plant Disease
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• v.13 no.2
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• pp.104-109
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• 2007

Pink root disease of onion, a known worldwide constraint upon onion production, significantly reduces crop levels in the main Korea cultivation area. In order to examine the effect of flooding on incidence of pink root disease caused by Pyrenochaeta terrestris and on onion growth and on populations of soil fungi, field experiments were conducted during two seasons, 2003/04 and 2004/05 at Onion Research Institute. Populations of soil fungi from fields were assayed on selective media. Flooding treatment was effective in reducing populations of P. terrestris, Pythium spp., and Rhizoctonia sp. in soil; fungal populations in soils flooded for 90 days were reduced to 1/2 to 1/3 of those in non-flooded soils. In nursery bed, protective activities of soils flooded for over 60 days were 93.5 to 99.2% and their pink root incidences were less than 5%, which were 1/11 to 1/18 of that in control. Increased yield of onion bulbs was associated with control of soil borne pathogenic fungi by flooding treatments. As flooding period was prolonged, bulb grade showed the tendency to increase. Soil flooding for over 60 days resulted in effective disease control, facilitated accurate planning of plant population in the field, extension of the growing-season and consequently higher yields of better quality.