• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.352-357
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• 2006

Results of development and activity of roots by rootstock sort of oriental melon were followed; Grafted seedlings had higher root growth than self-roots seedlings and among grafted seedlings, Shintozoa and Elite rootstocks had higher root growth. Grafted seedlings had more xylem exudate, which connects activity of roots, than self-root seedlings. Development of roots and increase of xylem exudate were better in higher temperature. Marketable yield was higher in grafted seedling and quality of fruit was higher in self-root seedling.

• Journal of Biosystems Engineering
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• v.43 no.3
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• pp.202-210
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• 2018

Purpose: Due to the growing demand for vegetables all year round, the use of vegetable transplanters has become widespread in agricultural production. However, the type of planting device used for the transplanter affects its overall efficiency. Problems such as inaccurate planting angles and inefficiently wide transplanting hole diameters of the planting device has limited the efficient use of some vegetable transplanters. Our goal in this study was to improve the efficiency of the transplanter by analyzing and modifying the linkages of the planting device of a vegetable transplanter. Methods: Because of its widespread usage in Korea, a linkage-type planting device was used for the experiment, which was divided into three parts. In the first part, the physical trajectory of the tranplanter was extracted using a CCD (charge-coupled device) camera and analyzed. In the second part, a simulated trajectory was developed using Recurdyn 3D software. The simulated and actual trajectories were then compared and analyzed. In the third part, based on the results of the comparison, improvements were made on the linkages of the transplanter and a demonstrative exercise was conducted. Finally, in experiment B, the performance was evaluated through an exercise using both the existing and improved planting devices. Results: The results demonstrated that the average planting angle was improved by 4.96 mm, the soil intrusion diameter was improved by 11.30 mm, and the planting depth was improved by 0.68 mm. Conclusion: It was concluded that the efficiency of a vegetable transplanter can be improved by modifying the linkages through simulations and field demonstrations.

• Applied Chemistry for Engineering
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• v.27 no.6
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• pp.664-668
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• 2016

The contamination in soil, underground water and river environment became serious due to illegal waste dumping. In this study, our research group analyzed the oil species of illegally disposed oils from J City. After pretreating the mixture of oil, water and solid phases to obtain homogeneous phase components, the physical property analysis, atom analysis, and gas chromatography were performed. From the results showing 11.8% of oxygen content, $-6^{\circ}C$ of pour point and chromatogram pattern. the contaminated oil was identified as a vegetable one. High performance liquid chromatography (HPLC) analysis was also performed in order to know what kind of vegetable oil was, and the ratio of LLO, OOL and POL was found to be high indicating that the disposed oil is majorly the used soybean oil with some vegetable oil mixtures. This study can be used for identifying contaminators for oils from the illegal waste dumping.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.820-828
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• 2015

This study was carried out to determine the effects of vernalization, temperature, and soil water deficit (SD) on mesophyll cells, growth, and yield of Chinese cabbage (Brassica campestris L). The palisade parenchyma and spongy tissues of Chinese cabbage were observed under full irrigation and two weeks of SD treatment. These cells were severely collapsed by four weeks SD treatment. The SD treatment had the greatest influence on the growth of Chinese cabbage among the tested treatment factors (vernalization, temperature, and SD), growth significantly decreased by severe drought treatment (four weeks SD treatment). In addition, the relative growth rate, unit leaf rate, leaf area ratio, specific leaf area, and leaf weight ratio were significantly affected by SD treatment; however, other individual factors and their combined treatments did not influence the analyzed growth parameters. The yield under vernalization after high temperature and full irrigation treatments was 3,056 kg/10 a, which was the greatest among all the tested treatments, while four-week SD treatment significantly reduced the yield. Head formation of Chinese cabbage was not altered under SD treatment, and vernalization treatments did not induce bolting. Our results indicated that collapsing mesophyll cells and reduced growth and yield were induced by SD treatment. Thus we suggest that optimal irrigation system should be install to avoid or overcome crippling drought conditions in the open field.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.457-463
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• 2014

This study was carried out to find out major factors to mitigate carbon emission using Life Cycle Assessment (LCA). System boundary of LCA was confined from sowing to packaging during vegetable production. Input amount of agri-materials was calculated on 2007 Income reference of white radish, chinese cabbage and chive produced at open field and film house published by Rural Development Administration. Domestic data and Ecoinvent data were used for emission factors of each agri-material based on the 1996 IPCC guideline. Carbon footprint of white radish was 0.19 kg $CO_2kg^{-1}$ at open fields, 0.133 kg $CO_2kg^{-1}$ at film house, that of chinese cabbage was 0.22 kg $CO_2kg^{-1}$ at open fields, 0.19 kg $CO_2kg^{-1}$ at film house, and that of chive was 0.66 kg $CO_2kg^{-1}$ at open fields and 1.04 kg $CO_2kg^{-1}$ at film house. The high carbon footprint of chive was related to lower vegetable production and higher fuel usage as compared to white radish and Chinese cabbage. The mean proportion of carbon emission was 35.7% during the manufacturing byproduct fertilizer; white radish at open fields was 50.6%, white radish at film house 13.1%, Chinese cabbage at outdoor 38.4%, Chinese cabbage at film house 34.0%, chive at outdoor 50.6%, and chive at film house 36.0%. Carbon emission, on average, for the step of manufacturing and combustion accounted for 16.1% of the total emission; white radish at open fields was 4.3%, white radish at film house 15.6%, Chinese cabbage at open fields 6.9%, Chinese cabbage at film house 19.0%, chive at open fields 12.5%, and chive at film house 29.1%. On the while, mean proportion of carbon footprint for the step of $N_2O$ emission was 29.2%; white radish at open fields was 39.2%, white radish at film house 41.9%, Chinese cabbage at open fields 34.4%, Chinese cabbage at film house 23.1%, chive at open fields 28.8%, and chive at film house 17.1%. Fertilizer was the primary factor and fuel was the secondary factor for carbon emission among the vegetables of this study. It was suggested to use Heug-To-Ram web-service system, http://soil.rda.go.kr, for the scientific fertilization based on soil testing, and for increase of energy efficiency to produce low carbon vegetable.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.96-102
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• 2020

Fusarium wilt caused by Fusarium oxysporum is a devastating disease limiting production of watermelon in Korea. The best way to control diseases is to use resistant gourd rootstock on watermelon. This study was conducted to establish an efficient screening method for resistant bottle gourd to Fusarium oxysporum f. sp. lagenaria. To develop an efficient inoculation method, incubation temperature after inoculation (15, 20, 25, and 30℃), inoculum concentration (1 × 10⁵, 5 × 10⁵, 1 × 10⁶, and 5 × 10⁶ conidia·mL^-1), and growth stages of seedlings (7, 10, 13, and 16 days) was investigated. Disease development of Fusarium wilt of bottle gourd was little affected by differences in incubation temperature and growth stages of seedlings. But resistant lines were more susceptible and appeared more severe symptoms at the higher inoculation level. Taken together, we suggest that an effective screening method for resistant gourd plant to Fusarium wilt is to dip the roots of 10-day old seedlings in spore suspension of 1 × 10⁵ - 1 × 10⁶ conidia·mL^-1, for 30 min, to transplant the seedlings into a non-infected soil, and then to incubate the inoculated plants in a growth room at 25℃ for 3 weeks to develop Fusarium wilt.

• Korean Journal of Soil Science and Fertilizer
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• v.24 no.2
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• pp.152-157
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• 1991

Growth status, plant nutrition and soil chemical properties were investigated for lettuce, spring onion and red pepper grown under vinyl house near Yesan. Low Ca and Mg with high K in soil resulted in Ca deficiency with slight Mg insufficiency in Korean lettuce. In this soil pH was low and EC was extremely low. Spring onion(Allium wakegi) can not emerge or showed poor growth(50%) due to high EC(above 0.5m mho/cm) and low pH (below 6.2). Red pepper plant showed wilt disease probably due to low soil pH.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.194-203
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• 2022

Cultivation of tomatoes in Korea grown in soil covers 89% of the total area for tomato cultivation. Tomatoes grown in soil often encounter various environment stresses including not only salt stress and soil-borne diseases but also cold stress in the winter season. This study was conducted to comparatively analyze the performance of rootstocks with cold stress by measuring the growth, yield, and photosynthetic efficiency in tomatoes grown in soil. The rootstocks were used 'Powerguard', 'IT173773', and '20LM' for the domestic rootstock cultivars and 'B-blocking' for a control cultivar. The tomato cultivar 'Red250' was used as the scion and the non-grafted tomatoes. Stem diameter, flowering position, leaf length, and leaf width were investigated for the growth parameters. The stem diameter of the non-grafted tomatoes decreased by 15% compared to the grafted tomatoes at 80 days after transplanting when exposed to low temperatures of 9-14℃ for 14 days. The leaf length and width of the non-grafted tomatoes were the lowest with 42.4 cm and 41.8 cm at 80 days after transplanting. The total yield per plant was the highest in tomato plants grafted on 'Powerguard' with 1,615 g and lowest in non-grafted tomatoes with 1,299 g. As the result of measuring the chlorophyll fluorescence parameters, PI_ABS and DI₀/RC, which mean the performance index and dissipated energy flux, 'Powerguard' was the highest with 3.73 in PI_ABS and the lowest with 0.34 in DI₀/RC, whereas non-grafted tomatoes was the lowest with 2.62 in PI_ABS and the highest with 0.41 in DI₀/RC at 80 days after transplanting. The stem diameter has positive correlation with PI_ABS, while it has negative correlation with DI₀/RC. The results indicate that can be analyzed by chlorophyll fluorescence parameters can be used for analyzing the differences in the growth of tomato plants grafted on different rootstocks when exposed to cold stress.

• Korean Journal of Agricultural Science
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• v.46 no.1
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• pp.103-111
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• 2019

Gray mold caused by Botrytis cinerea on strawberry plants is an economically significant disease in Korea. The rates for diseased fruits are high during the strawberry harvesting period from December to February, especially in hydroponic cultivation. This study assessed the effect of the nitrogen type in the soil culture and the electrical conductivity (EC) of the nutrient solution in a hydroponic culture on the gray mold incidence in 'Seolhyang' strawberry plants. The nitrogen sources assayed included calcium nitrate tetrahydrate (CN4), calcium nitrate decahydrate (CN10), ammonium sulfate (AS), and commercial fertilizer 213 (213). The effect of the EC was tested at 0.5, 0.8, 1.0, and $1.5dS{\cdot}m^{-1}$. The occurrence of gray mold varied according to the nitrogen type. The disease incidence and nitrogen content for the main nitrogen type were higher compared to the non-treated control. The AS treatment showed the highest occurrence of tipburn and gray mold. The incidence of gray mold as well as the nitrogen and phosphorus content of the leaves increased as the EC level was increased. These results indicate that the incidence of gray mold in strawberry plants is related to the nitrogen content of the leaf and the EC of the nutrient solution.

• Research in Plant Disease
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• v.28 no.1
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• pp.51-53
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• 2022

In January 2021, unusual outbreak of shoot rot symptoms was observed in young spikenard (Aralia cordata) plants growing in vinyl greenhouses located in Chuncheon and Yanggu, Gangwon Province, Korea. The symptoms initially appeared on young shoots of the plants at or above the soil surface level. Later, the infected shoots wholly rotted and blighted. The incidence of diseased plants in the vinyl greenhouses investigated ranged from 5% to 30%. Eight isolates of Rhizoctonia sp. were obtained from shoot lesions of the diseased plants. All the isolates were identified as Rhizoctonia solani AG-2-1 based on the morphological characteristics and anastomosis test. Three isolates of R. solani AG-2-1 were tested for pathogenicity on young shoots of spikenard plants using artificial inoculation. All the tested isolates induced shoot rot symptoms on the inoculated plants. The symptoms were similar to those observed in spikenard plants from the vinyl greenhouses investigated. This is the first report of R. solani AG-2-1 causing shoot rot in spikenard.