• Korean Journal of Agricultural Science
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• v.40 no.4
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• pp.425-434
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• 2013

Nowadays, the korean peninsula has endured weather changes toward to the subtropical climate. Also demographical structure has changed into multi-cultural society in which many people from subtropical areas have immigrated into Korea. Therefore, consumption and production of subtropical vegetables become important. For the analysis, we choose eight important subtropical crops. EDM (Equilibrium Displacement Model) with many parameters and elasticities is used for the forecast of consumption and required cultivation area. The simulation focuses on the changes of the number of foreign workers and immigrated women in Korea to predict the quantity of consumption and required area in Korea. The results show that we need additional land area about 581~1,065 ha for the cropping subtropical vegetables in Korea. Finally, these required area can be provided by the cities and counties in coast area in Gyeongsangnam-Do, Jeonranam-Do and Jeju-Do. Climate change will be continued in the future. Together with climate change, the change of demographical structure into multi-culture may increase consumption and production of subtropical vegetables. Forecasting of increased consumption and required cultivation area for subtropical vegetables is significant.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.10a
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• pp.133-137
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• 2003

• Culinary science and hospitality research
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• v.21 no.3
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• pp.181-197
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• 2015

This study examined the influence of perceived value, perceived quality, reasonable price of subtropical vegetables on trust, purchase intention and word of mouth among hotel chefs. For this investigation, a survey was carried out targeting hotel chefs in Korea with experience with subtropical vegetables. A total of 380 questionnaires were distributed to selected chefs over 20 days from October 1st to October 20th, 2014, of which 353 valid questionnaires were used after the exclusion of responses missing values or too much weighted tendency. A frequency analysis, factor analysis, correlation analysis, and multiple regression analysis were conducted with the use of the SPSS 18.0 package. The analysis results are as follows. First, perceived value, perceived quality and reasonable price had a positive influence on trust. Second, trust had a positive effect on purchase intention and word of mouth. Third, purchase intention positively influenced word of mouth.

• Korean Journal of Plant Resources
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• v.32 no.1
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• pp.45-52
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• 2019

In the process of adapting climate change, the government needs to provide policy and technical support necessary for growing promising crops imported from abroad. Therefore, this study was conducted to survey and analyze the conditions of growth of imported foreign crops and to derive response tasks. As a result, tropical and subtropical vegetables were cultivated 18 crops in 920 farms in 321 ha area (in 2015 year). The cultivation scale decreased in the order of Curcuma aromatica, Momordica charantia, Asparagus aethiopicus, Allium hookeri and Herbs. Tropical and subtropical fruits were cultivated 9 crops in 264 farms in 106.5 ha area (in 2015 year). Special and medicinal crops introduced abroad cultivated 10 crops in 753 farms in 276.3 ha area (in 2015 year). The cultivation scale decreased in the order of Curcuma longa, Glycyrrhiza uralensis, Lepidium meyenii and Moringa oleifera. For the stable settlement of domestic growth of tropical and subtropical crops introduced abroad, there should be safety and economic feasibility in terms of the cultivation environment according to the domestic culture adaptation test. Consideration needs to be given to the use of locally grown products in Korea, the securing of distribution and sales markets, and the competitiveness of imported products.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.359-376
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• 2016

Increase in world trade commodities along with climate change entails frequent pest insect invasions from subtropical to temperate zones. Tephritidae is one of two families in fruit flies along with Drosophilidae and consists of more than 5,000 species. Some tephritid flies in genera Anastrepha, Rhagoletis, Ceratitis, and Bactrocera are highly invasive and give serious economic damages on fruits and vegetables in temperate zones. This review focuses mainly on Bactrocera fruit flies, which have been well studied in control techniques to defend their invasion and colonization. Though various control techniques against Bactrocera fruit flies have been developed, less efforts have been paid to establish efficient integrated pest management (IPM) programs. This review introduces current control techniques of fruit flies and some successful IPM programs implemented in subtropical islands. In addition, major fruit flies infesting crops in Korea have been also reviewed in their occurrence and control programs.

• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.989-998
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• 2016

Acidic endo-polygalacturonases are the major part of pectinase preparations and extensively applied in the clarification of fruits juice, vegetables extracts, and wines. However, most of the reported fungal endo-polygalacturonases are active and stable under narrow pH range and low temperatures. In this study, an acidic endo-polygalacturonase (EPG4) was purified and characterized from a mutant strain of Penicillium oxalicum. The N-terminal amino acid sequence of EPG4 (ATTCTFSGSNGAASASKSQT) was different from those of reported endo-polygalacturonases. EPG4 displayed optimal pH and temperature at 5.0 and 60-70℃ towards polygalacturonic acid (PGA), respectively, and was notably stable at pH 2.2-7.0. When tested against pectins, EPG4 showed enzyme activity over a broad acidic pH range (>15.0% activity at pH 2.2-6.0 towards citrus pectin; and >26.6% activity at pH 2.2-7.0 towards apple pectin). The K_m and V_max values were determined as 1.27 mg/ml and 5,504.6 U/mg, respectively. The enzyme hydrolyzed PGA in endo-manner, releasing oligo-galacturonates from PGA, as determined by TLC. Addition of EPG4 (3.6 U/ml) significantly reduced the viscosity (by 42.4%) and increased the light transmittance (by 29.5%) of the papaya pulp, and increased the recovery (by 24.4%) of the papaya extraction. All of these properties make the enzyme a potential application in the beverage industry.

• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.10-15
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• 1984

To get information on the behavior of phorate in vegetables under the subtropical conditions, phorate granule (10%) was applied to silt loam soil at the rate of 40㎏ a.i./ha and incorporated to 10㎝ soil depth just befere sowing. Insecticide residues in vegetables were determined with GLC and confirmed qualitatively with TLC. Phorate and its metabolites were absorbed by the radish and carrot roots and rapidly translocated into foliages. The compounds detected in vegetables were phorate, phorate sulfoxide, and phorate sulfone. Residue levels of compounds in radishes were higher in foliages than in roots and much more residues were present in leaf lamina than in midribs. The concentration of the total residues in vegetable roots was rapidly decreased with the time, while the amount of total residues in radish roots was increased with the time. Therefore, the rapid decline of residue levels in vegetables was mainly attributed to the dilution of insecticide residues by the rapid growth of these vegetables.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.196-201
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• 2015

This study was conducted to seek optimum sowing time and pinching height for tender shoots production of moloheiya (Corchorus olitorius L.), which is a subtropical leaf vegetables, under an unheated greenhouse in the south of Korea. Seeds of moloheiya did not germinate at all at $10^{\circ}C$, but germinated well at $18{\sim}30^{\circ}C$ with 95.5~98.5% germination rate. Germination rate was 75.0% at $15^{\circ}C$, but germination speed was very low. The pods of moloheiya sown before April 28 was matured after late-August, but those sown after May 7 was not matured in that year. In tender shoot production and harvest frequency, treatment sown on April 14 was most plentiful among sowing time treatments, and showed marketable yield increase by 14~42% compared to other sowing times. Mean-while, pinching at 100cm high from soil surface was more effective than other heights for increment of branches and tender shoot. All above suggest that it was suitable to sow seed on mid-April and to pinch at 100cm high from soil surface for increment of tender shoots in the south of Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1656-1663
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• 2009

The antioxidant activities of water extracts from wild vegetables such as Ligularia fischeri (GC), Capsicum annuum L. (GCY), Aster scaber (CNM), Petasites japonicus S. et Z. Max (MYD), Ipomoea batatas L. (Lam) (GGM) were evaluated and compared with water extracts from freeze dried block. The antioxidant properties of water extracts from wild vegetables and their freeze dried block were evaluated using different antioxidant tests; 2.2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging, hydroxyl radical scavenging and nitrite scavenging activities. The water extracts from wild vegetables were found to have a higher total phenolic content than water extracts from freeze dried block. Total phenolic contents of water extracts from GC, GCY, CNM, MYD, and GGM were $471.66{\pm}3.52\;{\mu}g/mg,\;141.33{\pm}2.51\;{\mu}g/mg,\;177.33{\pm}2.88\;{\mu}g/mg,\;238.66{\pm}9.50\;{\mu}g/mg\;and\;122.67{\pm}3.51\;{\mu}g/mg$, respectively. At the concentrations of 1000 ppm, water extracts from GC, GCY, CNM, and GGM showed higher activities than water extracts from their freeze dried block on DPPH radical scavenger activity. The activity of water extracts from CNM, GC, GCY, MYD, and GGM were 90.9%, 89.9%, 76.6%, 71.1%, and 57.4%, respectively. When 10000 ppm of GC, GCY, CNM, MYD, and GGM water extracts tested for hydroxyl radical scavenging activity, activities were increased by 38.8%, 33.4%, 35.9%, 34.3%, and 33.8%, respectively and a similar effect was found with water extracts from GCY, CNM, and GGM freeze dried block at 10000 ppm concentration. However, the water extracts from GC and MYD was slightly more effective than freeze dried block extracts. The water extracts from wild vegetables and their freeze dried block had effective DPPH radical scavenger activity and hydroxyl radical scavenging activity at all tested concentrations. Nitrite scavenging activity of GC water extract significantly increased in a dose-dependent manner and the extract had higher nitrite scavenging activity than extracts freeze dried block extracts. We found that freeze dried block maintained antioxidant activities of the wild vegetables.

• Korean Journal of Ecology and Environment
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• v.47 no.1
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• pp.32-40
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• 2014

This study was conducted to evaluate the growth response of economical six leafy vegetables that are crown daisy, pak-choi and four kinds of lettuce (Red leaf lettuce, Green leaf lettuce, Head lettuce, Romaine lettuce) by light treatment of LED in plant factory. The light treatments were composed of red, blue, red+farred, red+blue, red+blue+white LEDs, irradiation time ratio of the red and blue LED per minute (1 : 1, 2 : 1, 5 : 1, 10 : 1), and duty ratio of mixed light (100%, 99%, 97%). The following results were obtained in different LED light sources treatments: Shoot biomass and S/R ratio of romaine lettuce were the highest under mixed red+blue LEDs. S/R ratio of head lettuce was higher under mixed red+blue+white LEDs than red+blue LEDs. The others showed no difference in LED light treatment. Shoot biomass, total biomass and S/R ratio of green lettuce, head lettuce and pak-choi were highest in the higher red ratio (5 : 1) on irradiation time of red : blue LED ratios. By the different duty ratio (red+blue and red+blue+white LEDs), Under the mixed light of red+blue, shoot and root biomass of crown daisy and romaine lettuce were high in duty ratio of 100% and 99%, and S/R ratio was highest in all the 6 kinds in duty ratio of 97%. All the 6 kinds showed a fine growth state in low duty ratio (97%). Green lettuce, romaine lettuce and pak-choi showed relatively high shoot biomass and total biomass in low duty ratio of 97% under the mixed light of red+blue+white. S/R ratio of romaine lettuce and head lettuce were highest in the duty ratio of 97% with red+blue+white LEDs. Thus, we can cultivate stably without reference to external factors, if we use appropriate light sources and light quality in closed-type plant factory.