• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.44-50
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• 2000

Tolerance mechanism to flupyrazofos was examined with Plutella xylostella (L.) and Spodoptera exigua by investigating the penetration rate of flupyrazofos into larvae body. On determining effective washing of $^{14}C$-flupyrazofos, the washing volume to recover over 98% of $^{14}C$-flupyrazofos was observed at three times (each time: 1 mL). To select a suitable solvent, the recovery rates of each solvent in 3rd instar larvae of DBM were above 98%, but the washing rates of acetone, hexane and ethyl-acetate were 85.1%, 67.2% and 68.4%, respectively. In the BAW larvae, although the recovery rates of each solvent were above 99%, the washing rates of acetone, hexane and ethyl-acetate were 83.5%, 65.9% and 71.7%, respectively. The $PT_{50}$ values of $^{14}C$-flupyrazofos were 0.731 h (44 min) in the DBM larva and 0.504 h (30 min) in the BAW larva. Radiocarbon in acetone washing (external fraction) decreased more quickly in the BAW larva than in the DBM larva, and amount of radiocarbon in larvae body increased more quickly with time in the DBM larva than in the BAW larva. In contrast, amount of radiocarbon in excreta increased more rapidly with time in the BAW larva than in the DBM larva.

• The Korean Journal of Pesticide Science
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• v.10 no.1
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• pp.50-55
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• 2006

A field-resistant strain of the diamondback-moth(Plutella xylostella L.), collected from Chinese cabbage alpine farmland at Gangwon-do, Korea, was used for determination of the characteristics of resistance to chlorpyrifos using the activities of esterases and glutathione-S-transferase(GST), protein sequestration and AChE insenstivity. Although the activities of esterases extracted from resistant strain and susceptible strain were not significantly different, isozyme bands shown on the electrophoresis were different. GST activity from field resistant strain was 1.5-fold higher than that of susceptible. No differences were shown between resistant and susceptible ones in protein sequestration. The insensitivities of AChE to chlorpyrifos, however, extracted from susceptible strain was 460-fold higher than those of resistant. These results indicated that the insensitivity of AChE is the major factor for developing the resistance and activities of GST might be a minor factor.

• The Korean Journal of Pesticide Science
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• v.13 no.3
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• pp.197-202
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• 2009

Based on the insecticidal efficacy by insecticide treatment methods, neurophysiological responses were compared with the larvae of diamondback moth (DBM) and beet armyworm (BAW) using pyrethroids working on nervous system. By body spray method, all pyrethroids were showed lower insecticidal activity below 50% on the larvae of DBM and BAW. By leaf dipping method, DBM larvae were showed the insecticidal activity as 100% at 50 ppm deltamethrin, 80.0% at fenvalervate and 63.3% at permethrin. However, BAW larvae were showed lower insecticidal activity as similar as control in all concentration. In order to examine electrophysiological response on nervous system on DBM and BAW larvae when treated three insecticides, we investigated the voltage and reaction degree. The voltage of DBM were responded as high as $10^{-7}M$ in deltamethrin, $10^{-5}M$ in fenvalerate and $10^{-3}M$ in permethrin. However, those of BAW were showed dull responses with small variation of voltage to all three insecticides.

• Journal of Life Science
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• v.14 no.5
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• pp.778-787
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• 2004

Effect of the microbial product made of Bacillus stearothermophilus DL-3, which was isolated from the soil and identified in this study, and rice bran on microorganisms in soil and growth of lettuce (Red skirt lettuce) and Chinese cabbage (Ga rack new No.1 Chinese cabbage) was investigated. Total numbers of microorganisms in the pot with untreated soil, treated with standard amount of microbial product and treated with double amounts of microbial product for growth of lettuce after 6 weeks were 2.78${\times}$10$^{7}$ CFU/g, 2.72${\times}$10$^{8}$ CFU/g and 3.63${\times}$10$^{8}$ CFU/g. Total numbers of microorganisms in the soil without treatment of microbial product and treated with standard amount of microbial product were 2.06${\times}$10$^{8}$ CFU/g and 5.49${\times}$10$^{8}$ CFU/g. Total numbers of microorganisms in the pot with untreated soil, treated with standard amount of microbial product and treated with double amounts of microbial product for growth of Chinse cabbage after 6 weeks were 1.43${\times}$10$^{7}$ CFU/g, 3.42${\times}$10$^{8}$ CFU/g and 7.22${\times}$10$^{8}$ CFU/g. Total numbers of microorganisms in the soil without treatment of microbial product and treated with standard amount of microbial product were 5.75${\times}$10$^{8}$ CFU/g and 7.96${\times}$10$^{8}$ CFU/g. On basis of leaf length, leaf width, leaf number, wet weight and dry weight, the growth of lettuce and Chinese cabbage on the soil treated with microbial product was faster than that on the untreated soil. The treatment of microbial product in the soil resulted in the increase of useful microorganisms, which seemed to enhance the growth of lettuce and Chinese cabbage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.6
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• pp.794-799
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• 2007

Nitrate contents and quality characteristics of Ulgari-Baechu Kimchi, Yulmoo Kimchi, and Yulmoo Mul-Kimchi were investigated during a storage period. In case of Ulgari-Baechu Kimchi and Yulmoo Kimchi, an increase of pH and decrease of acidity were distinguished by the 4th day of the storage after fermentation. In Yulmoo Mul-Kimchi, pH value decreased and total acidity increased through the whole storage period. Total microbial and lactic acid bacterial counts of Yulmoo Kimchi and Ulgari-Baechu Kimchi reached the peak at the 4th day of storage and slowly decreased after the 18th day. Total microbial and lactic acid bacterial counts of Yulmoo Mul-Kimchi were also the highest at the 4th day of fermentation but showed gradual decreases from the same day. Nitrate contents of Ulgari-Baechu Kimchi significantly decreased by fermentation at room temperature, which continued during the whole store period to down by 11%. Showing the similar pattern in the nitrate content change, Yulmoo Kimchi and Yulmoo Mul-Kimchi recorded 12% and 5% decrease, respectively.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.488-494
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• 1999

Changes of lactic acid bacteria and fermentation patterns were investigated during fermentation of Green Onion Kimchi and Chinese Cabbage Kimchi at 10 and $20^{\circ}C$. Fermentation of Green Onion Kimchi proceeded more slowly than Chinese Cabbage Kimchi in point of changes of pH, total acidity and total viable cell number. Maximum number of total viable cell, Leuconostoc, and Lactobacillus in Green Onion Kimchi were smaller than in Chinese Cabbage Kimchi. And these differences were larger in fermentation at $10^{\circ}C$. Total sugar content of Green Onion Kimchi was higher than Chinese Cabbage Kimchi not only at the beginning of fermentation but also at the end of fermentation. Therefore, the reason for the slow fermentation of Green Onion Kimchi was not low sugar content. Major lactic acid bacteria of properly fermented Green Onion Kimchi were identified as Lactobacillus plantarum and Leuconostoc mesenteroides which had been reported to be major lactic acid bacteria isolated from Chinese Cabbage Kimchi.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.278-284
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• 1990

A study relating the soluble-solids (S.S.) contents of Chinese cabbages to the final titratable acidities(TA) of kimchis was conducted. The S.S. contents of Spring-sowed Chinese cabbages were in the range from $1.20-3.40^{\circ}$ Brix while those of Autumn-sowed Chinese cabbages were in the range from $3.8-6.6^{\circ}$ Brix. The S.S. contents of Chinese cabbages were varing depending on their varieties and the cultivating seasons. However, seasonal variations were much more significant than the varietal variations. The final TAs of kimchis after complete fermentation were found to be directly proportional to the S.S. contents(x) of Chinese cabbages, showing that TA equals to 0.30x+07779. From the equation, a Chinese cabbage of a S.S. content with up to $0.02^{\circ}$ Brix, which is practically impossible to obtain, will make a kimchi which will not be overacidified during the prolonged storage period without any preservative measures.

• Korean journal of applied entomology
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• v.25 no.3 s.68
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• pp.183-189
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• 1986

Fifty three diseased root samples of Chinese cabbage and 22 soil samples were taken from six alpine areas in Kangwon province to examine the organisms causing root rot of Chinese cabbage. Among thirteen microorganisms detected from diseased roots samples, Pythium ultimum, Pythium echinocarpum and Rhizoctonia solani were detected frequently and were pathogenic to Chinese cabbage. Five to 100% of young Chinese cabbage plants grown in the sample soils taken from alpine cabbage fields were infected either alone or together with P. ultimum, P. echinocarpum and R. solani, depending upon the or gin of sample soils. When relative density of the three organsims in the sample soils was estimated based on the infection frequency on the plants grown in those sample soils, P. ultimum was prevalent only in Chahang-i-li area. P. echinocarpum was prevalent in Yongsan-il-li, Hoengwe-li, and Munmaek areas. R. solani was solely found in Maebongsan area where both P. ultimum and P. echinocarpum were not detected. In the three areas where both P. ultimum and P. echinocarpum were present, density of P. echinocarpum was generally greater than that of P. ultimum. Seedlings of thirty major Chinese cabbage varieties were inoculated independently with the three organisms in the greenhouse. Six varieties were resistant to P. ultimum. Three and two varieties were moderately resistant to P. ultimum and P. echinocarpum, respectively. All varieties were highly susceptible to R. solani.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.17-21
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• 2001

To develop a selection system for regenerating plants from transformed tissues, effects of four antibiotics (kanamycin, hygromycin, carbenicillin, cefotaxime) and herbicide (phosphinotricin) on shoot regeneration from cotyledon and hypocotyl explants of Chinese cabbage (Brassica campestris L. ssp. pekinensis) were studied. For cotyledon, shoot induction was not significantly affected by kanamycin at $1mg{\cdot}L^{-1}$, but the number of shoots formed was significantly reduced at $2mg{\cdot}L^{-1}$, and no shoots were regenerated from any explants at $6mg{\cdot}L^{-1}$ or higher. Hypocotyl explants showed similar result as cotyledon. Kanamycin at $7mg{\cdot}L^{-1}$ may be adequate for selecting Chinese cabbage transformants. Hygromycin at $4mg{\cdot}L^{-1}$ or higher completely inhibited the growth and shoot regeneration of Chinese cabbage explants. Therefore, resistance gene to hygromycin may also be used as a selective marker for Chinese cabbage transformation. Carbenicillin and cefotaxime, the cephalosporin type of antibiotics, had little effect on shoot regeneration of Chinese cabbage explants. Since carbenicillin and cefotaxime have low toxicity to Chinese cabbage, they are suitable for use in tissue culture to eliminate Agrobacterium in transformation experiments after co-cultivation. Shoot regeneration from cotyledon and hypocotyl explants was significantly reduced in presence of $1mg{\cdot}L^{-1}$ phosphinotricin (PPT) and completely inhibited by $2mg{\cdot}L^{-1}$ or higher. PPT, same as antibiotics, may also be used to select transformed cells. Since Chinese cabbage is known to be recalcitrant to in vitro shoot regeneration compared to other Brassica species, even though lower levels of selectable markers result in more transformants but simultaneously allow more untransformed escapes to develop, lower levels of antibiotics and herbicides could be successfully used as a selectable marker to reduce selection pressure.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.731-743
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• 2018

This study was conducted to evaluate the effects of green manures and complemental fertilization with oil cake or liquid fertilizer on growth and nitrogen use efficiency of Chinese cabbage cultivated in organi systems. Field experiments were carried out at the National Institute of Agricultural Science in Suwon, South Korea from 2012 to 2014. Two green manure crops, Crotalaria and Hairy vetch, was cultivated in summer and in winter, respectively. The application methods of the green manure consisted of three tillage systems (overall tillage, partial tillage and no tillage). Oil cake and liquid fertilizer were used as complemental fertilizer. The results showed that when used as covering material in the upland soil without tillage, green manure fertilization was more effective in increasing growth and yield of Chinese cabbage than when incorporated into soil. It was possible to grow and harvest Chinese cabbage in the spring season by the application of hairy vetch as winter green manure. The higher yield of Chinese cabbage with green manure application was caused by the lower incidence rate of soft rot and tip-burn. The yield of the Chines cabbage that received green manure applications over two consecutive seasons followed by the supplemental fertilization with oil cake was similar to that of the conventional chemical fertilization. Following a single season green manure application in summer, however, the yield of cabbage was only about 70% of the conventional treatment. Green manure cultivation with additional liquid fertilization produced a yield similar to the conventional fertilization treatment, soil inorganic nitrogen concentration remained stable and the nitrogen use efficiency increased in the green manure applied soil. In conclusion, the organic cultivation of Chinese cabbage in the autumn season could be outperformed in the upland soil receiving two seasons (winter and summer) of green manure fertilization followed by the supplemental fertilization with liquid fertilizer.