• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.180-185
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• 2007

The effects of selenium (Se) and germanium (Ge) fertilization on the growth and quality of Chinese cabbages cultivated in spring and autumn and peppers cultivated in spring were investigated. $Se\;(Na_2SeO_4)\;and\;Ge\;(GeO_2)$ were supplied 5, 10, or 20 times in an aqueous solution of 0, 2, 4, or $8mg{\cdot}L^{-1}$ during the cultivation of Chinese cabbages and peppers. The fresh weight of Chinese cabbages increased by Ge fertilization with high concentration. But it was not affected by Se fertilization. The content of vitamin C increased by 10 times application with $4mg{\cdot}L^{-1}$ of Se or Ge. The concentration of Se in Chinese cabbage increased according to increasing concentration of Se fertilization. Se concentration was higher in the outer leaves than in the inner leaves. Se concentration in the mesophyll was higher than that in the midrib. Ge fertilization increased the uptake and concentration of Ge in autumn-cultivated Chinese cabbages. Se and Ge fertilization did not affect the fresh weight of peppers. The content of vitamin C in pepper increased by 20 times application of $2mg{\cdot}L^{-1}$ of Se. Vitamin C content in red peppers was twice as much as in green peppers.

• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.194-200
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• 2011

Diamondback moth (DBM, Plutella xylostella L.) is known as the most destructive pest of cruciferous crops worldwide. As most insecticides targeted to mainly larval stage, new insecticides which have hatching-inhibitory or ovicidal activity could be more efficient to control DBM. Therefore, we developed an easy and efficient method for screening ovicidal activity of DBM eggs using aluminum foil. The aluminum foil ($4{\times}12$ cm) coated with filtered juice of chinese cabbage leave (hereinafter called oviposition foil) exposed to 300 newly-emerged adults for 24 hours inside the rearing container. The oviposition foils were replaced every 4 days consecutively after mating, but it was better to discarded over then. Oviposition foil were divided into 6 to 12 pieces depending on egg mass volume. After dipping into test solutions for 10 seconds using faucet, oviposition foil pieces were placed into common petri dish, and then investigated hatchability. The effect of methanol solvent (50%) for 10 seconds dipping on the toxicity against DBM eggs was negligible. In addition, whether covering the petri dish or not should be dependent on nature of active compounds tested. With applying the new bioassay method, methanol extracts from 50 plants were tested the ovicidal activity to DBM eggs. Among them, four plant extracts; Angelica tenuissima root, Lycium chinense root, Cnidium officinale root and Polygala tenuifolia root, showed high ovicidal activity of over 90% control efficacy, against DBM eggs.

• Food Science and Preservation
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• v.14 no.1
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• pp.24-29
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• 2007

Quality changes in winter Chinese cabbages were evaluated during low temperature storage. Flesh and salt-treated Chinese cabbages were put into (a) polyethylene (PE) film sacks (size: $40cm{\times}60cm$, thickness: 0.03 mm, with four perforations each 8 mm in diameter), (b) plastic containers or (c) polypropylene (PP) nets and stored at $0^{\circ}C$. Also, Cabbages were also wrapped in newspapers and stored underground where the average temperature was $2.7^{\circ}C$. The weight loss rates of Chinese cabbages stored in PP nets and plastic containers were greater than those of cabbages stored with PE or wrapped in newspaper. Chinese cabbages wrapped in newspaper and stored underground needed much greater trimming compared to cabbages stored in other ways. The firmness and the soluble solid contents of Chinese cabbages were not affected by the various storage treatments. A better appearance was retained when Chinese cabbages were stored in PE film sacks. Chinese cabbages in PE film sacks stored at $0^{\circ}C$ showed delayed weight loss, less trimming loss, and less change in appearance. The quality changes in salted Chinese cabbages (desalting losses, pH changes, osmolarities, and crude fiber content) were not significantly different after the various treatments. No storage treatment was effective in maintaining a high quality of salted winter Chinese cabbage.

• Korean Journal of Plant Resources
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• v.26 no.1
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• pp.19-25
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• 2013

This study focused on the usefulness of plant extracts for a city organic farm. Insecticidal activity of 8 plant species, plants crude extracts by ethanol and water, against third instar larvae (susceptible strain) of Plutella xylostella was evaluated in this study. Ethanol(25%) extracts of plant materials had better insecticidal activity than water extracts at the room temperature. Insecticidal activity were investigated by leaf disc spray method. Five plant extracts (Capsicum annuum, Chelidoniun majus, Leonurus sibiricus, Coptis japonica, Mentha piperascens) showed over 50% insecticidal activity to P. xylostella at the concentration of $1500mg{\cdot}L^{-1}$. Extract of C. annuum showed the highest insecticidal activity (83.3%) against P. xylostella. Phytotoxicity was not observed on Raphanus sativus and Brassica campestris with spray application. Seed germination and growth of two plants were not affected. Extract of C. japonica revealed 73.3% control efficacy against P. xylostella of R. sativus and showed 70% control efficacy against those of B. campestris, respectively, in plastic house. Insecticidal activity against various insects was observed in C. japonica extract as 87.4% for R. sativus and 74.3% for B. campestris in the field. These results suggested that extracts of C. annuum, C. japonica showed the highest insecticidal activity, and could be used as city farm insecticides for organic farming.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.93-96
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• 2014

This study was conducted to determine the economic injury levels and control thresholds for the striped cabbage flea beetle, Phyllotreta striolata (Coleoptera: Chrysomelidae), on Chinese cabbage at two different planting times. The number of inoculated adults per 10 cabbages was 0, 2, 4, 8, and 16 at the early developmental stage of the cabbage5 days after planting) and 0, 10, 20, 30, and 40 at the middle developmental stage (30 days after planting). Damages to the leaves at the first inoculation were 2.5-21.1% and at the second inoculation were 1.8-26.3% after harvesting. The linear relationships between population density and yield reduction were as follows: Y = 1.3475X + 2.135 ($R^2$ = 0.8699) at the early developmental stage and Y = 0.703X - 1.78 ($R^2$ = 0.966) at the middle developmental stage. On the basis of these results, the economic injury levels caused 5% loss of yield; there were 2.1 adults per 10 Chinese cabbage at the early developmental stage and 9.6 adults per 10 Chinese cabbage at the middle developmental stage.

• Korean Journal of Environmental Agriculture
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• v.29 no.3
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• pp.293-299
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• 2010

The aim of this study was to investigate the possible impact of Bt Chinese cabbage on the soil microbial community. Microbial communities were isolated from the rhizosphere of one Bt Chinese cabbage variety and four varieties of conventional ones and were subjected to be analyzed using both culture-dependent and molecular methods. The total counts of bacteria, fungi, and actinomycetes in the rhizosphere of transgenic and conventional Chinese cabbages were observed to have an insignificant difference. Denaturing gradient gel electrophoresis (DGGE) analysis of PCR-amplified 16S rRNA genes revealed that the bacterial community structures were very similar to each other and this genetic stability of microbial communities was maintained throughout the culture periods. Analysis of dominant isolates in the rhizosphere of transgenic and conventional Chinese cabbages showed that the dominant isolates from the soil of transgenic Chinese cabbage belonged to the Bacilli and Alphaproteobacteria, while the dominant isolates from the soil of conventional cabbage belonged to the Holophagae and Planctomycetacia, respectively. These results indicate that the Bt transgenic cabbage has no significant impact on the soil microbial communities.

• Journal of Plant Biotechnology
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• v.33 no.4
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• pp.271-276
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• 2006

Hypocotyl explants of Chinese cabbage (us. 'Jeong Sang' and 'Seoul') produced adventitious shoots on Murashige and Skoog (MS) basal medium supplemented with 4mg/L $AgNO_3$, 5 mg/L acetosyringone, 4 mg/L 6-benzyladenine and 3mg/L alpha-naphthaleneacetic acid (SI) after cocoultivation with strains of Agrobacterium tumefaciens (LBA4404) harboring the pCAMBIA1301 and the $_PPTN290$ containing hygromycin-resistance gene and paromomycin-resistance gene as a selectable marker genes, respectively. There was a significant difference in the frequency of transgenic plants depending on antibiotics and cultivars used. Paromomycin was better than hygromycin, and cultivar 'Jeong-sang' was higher than 'c.v. Seoul' in the frequency of transgenic plants. In particular, the highest frequency (0.70%) of transgenic plants was obtained from selection medium (SI) containing 100mg/L paromomycin in c.v., 'Jeong-sang' GUS positive response were obtained 9 plants and 3 plants from the cultivars, 'Jeong-sang' and 'Seoul', respectively. They were grown to maturity in a greenhouse and normally produced $T_1$ seeds. GUS histochemical assay for progeny $(T_1)$ revealed that the transgenes were expressed in the plant genome.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.2
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• pp.205-213
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• 2018

Development and validation of crop models often require measurements of biomass for the crop of interest. Considerable efforts would be needed to obtain a reasonable amount of biomass data because the destructive sampling of a given crop is usually used. The Kinect sensor, which has a combination of image and depth sensors, can be used for estimating crop biomass without using destructive sampling approach. This approach could provide more data sets for model development and validation. The objective of this study was to examine the applicability of the Kinect sensor for estimation of chinese cabbage fresh weight. The fresh weight of five chinese cabbage was measured and compared with estimates using the Kinect sensor. The estimates were obtained by scanning individual chinese cabbage to create point cloud, removing noise, and building a three dimensional model with a set of free software. It was found that the 3D model created using the Kinect sensor explained about 98.7% of variation in fresh weight of chinese cabbage. Furthermore, the correlation coefficient between estimates and measurements were highly significant, which suggested that the Kinect sensor would be applicable to estimation of fresh weight for chinese cabbage. Our results demonstrated that a depth sensor allows for a non-destructive sampling approach, which enables to collect observation data for crop fresh weight over time. This would help development and validation of a crop model using a large number of reliable data sets, which merits further studies on application of various depth sensors to crop dry weight measurements.

• Food Science and Preservation
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• v.19 no.5
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• pp.659-664
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• 2012

The fermentation and quality characteristics of Cheonggukjang with Chinese cabbage, which is produced as a by-product in the kimchi industry, were investigated. Cheonggukjang was prepared with cooked soybean without Chinese cabbage (control), with 10% Chinese cabbage (A10), and with 20% Chinese cabbage (A20), respectively. The A10 and A20 pH values did not show a significant difference compared with the control during fermentation for 72 h. The total aerobes of the Cheonggukjangs reached 8.65 (control), 8.73 (A10), and 9.11 (A20) log CFU/mL after fermentation for 72 h at $37^{\circ}C$, respectively. The numbers of lactic acid bacteria were found to be 5.62 (A10) and 5.87 (A20) log CFU/mL during fermentation for 72 h at $37^{\circ}C$, but lactic acid bacteria were not detected in the control. The amino nitrogen and viscous substance contents of A10 and A20 were lower than those of the control. The total polyphenol contents and DPPH radical scavenging abilities of the tested Cheonggukjang were increased by fermentation. The increasing ratio of polyphenol and the DPPH radical scavenging ability of A10 were higher than those of the control and of A20. The sensory quality of A10 was higher than that of the control and of A20 in taste, color, and overall acceptability.

• Food Science and Preservation
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• v.15 no.1
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• pp.43-48
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• 2008

This experiment investigated the characteristics of salted and fresh Chinese cabbages of different cultivars and using various cultivation methods. We measured the numbers of leaves, sizes, thicknesses, moisture contents, and firmness qualities of fresh Chinese cabbage grown in a plastic house, and outdoors. 'The bulb sizes, leaf thicknesses, and moisture contents of leaves were higher after plastic house cultivation than after growth in the field. Plastic house culture increased the growth rate of Chinese cabbage. Firmness and osmolarity showed better values after outdoor cultivation, however. The growth rates and the levels of chemical components were affected by interactions between cultivation methods and cultivars of Chinese cabbage. The salt levels of salted Chinese cabbage were 1.21.7% (w/w) after cabbages cultivated outdoors were preserved, and 0.91.2 % (w/w) after vegetables grown in a plastic house were treated. The quality properties of postharvest Chinese cabbages after salting varied with cultivation method even when the same cultivars of Chinese cabbage were used. The salt contents of salted Chinese cabbage thus varied with different cultivation methods. The results indicate that the properties of Chinese cabbage vary with the culture systems adapted.