• Korean Journal of Food Science and Technology
• /
• v.20 no.6
• /
• pp.742-748
• /
• 1988

The macro-and microstructure of Chinese cabbage used for Korean Kimchi preparation were examined and the texture characteristics of raw cabbage leaf and salted or blanched leaves were evaluated by cutting test. The length and thickness of leaf stalk increased with the order of pyllotaxis, but the thinning effect of outermost leaves was observed. The microstructure of cut-profile of stalk showed densely compacted vascular systems aligned in the center of stalk and the outer space was filled with large parenchima cells. Due to this structure, characteristic cutting curves were obtained by cutting test, composing three peaks of cutting for inner surface skin, center vascular system and outer surface skin. Salting and blanching increased the cutting force mainly due to the increase of Gutted cell wall number caused by the structure collapse.

• Korean Journal of Environmental Agriculture
• /
• v.1 no.2
• /
• pp.89-92
• /
• 1982

Persistence of cyanofenphos on Chinese cabbage under the different climate conditions was studied by spraying the insecticide at the rate of 0.5 and 0.75 ㎏ AI/ha at 22 and 36 days after transplanting and monitoring its residues upto 35 days after the final spray. At both spraying rates the degradation patterns of the insecticide, regardless of climate condition, showed similar trends; cyanofenphos residues on Chinese cabbage declined rapidly upto 14 days after the final spray but more slowly thereafter. Half-life for cyanofenphos on Chinese cabbage was $6{\sim}7$ days. The half-life was little affected by the spraying rate and time. Based on the FAO/WHO maximum residue limit of cyanofenphos on common cabbage (2 ppm), it is recommended that the pre-harvest intervels of the insecticide on Chinese cabbage could be 16 and 19 days for 0.5 and 0.75 ㎏ AI/ha, respectively.

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.4
• /
• pp.253-258
• /
• 1993

This study reports the influence of application of sulphur on the yield and some quality by Chinese cabbage in field experiment. 1. By the application of sulphur fertilizer, the yields of Chinese cabbage were increased about 11~13 percent compared to control. 2. After harvest, the available sulphur amount in soil was increased, while the soil pH decreased. 3. The accumulation of nitrate in Chinese cabbage leaves was reduced by the sulphur application. 4. The amount of biochemical materials such as water-soluble pectin, phenolic compound, sugar, vitamin C in leaves were increased by sulphur application.

• Food Science and Preservation
• /
• v.10 no.1
• /
• pp.23-27
• /
• 2003

This study was conducted to develop the corrugated fiberboard box which is suitable to pre-cooling and low temperature distribution of chinese cabbage Consider from a cooling performance viewpoint, the folding type box with 5.4% vent hole ratio was most efficient for fast cooling and even temperature distribution in the packaging box. At the end of storage periods, the compressive strength of the folding type box was less than the bliss type box. However, the compressive strength of the folding type box after storage was higher than required safety compressive strength for long term storage. So the folding type box was considered to have no problems toy practical use. The shelf-life of the chinese cabbage packaged with the developed box was 6∼7 days which was 2∼3 days longer than usual packaging.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.16 no.2
• /
• pp.75-82
• /
• 1987

This study was to investigate physicochemical and microbial changes that took place during the salting of chinese cabbages. Salinity(3%) that is suitable for kimchi preparation was reached when chinese cabbages were salted for seven hours in 10%, three hours in 15% and one hour in 20%. In the case of 5% it was not reached though they were salted for over twelve hours. In order to decrease salinity from 7% level of salted chinese cabbages to 3% level by soaking in tap water, 1.2 hours for leaf and three hours for patiole were spent. Volume, moisture, firmness and internal space of raw chinese cabbages were significantly decreased by salting (15%, 10 hours) : volume, 59.90%, moisture, about 31.92% and internal space rate, 35.06%. Contents of mono-and divalent cations$(K^+,\;Mg^{2+}\;and\;Ca^{2+})$ were reduced whereas $Na^+$ content was greatly increased; therefore, in the future the increase of Na-content remains open to question. By salting and washing, mold, yeast and bacteria were decreased by 58%, 40%, 45%, respectivity.

• Food Science and Preservation
• /
• v.8 no.1
• /
• pp.23-29
• /
• 2001

To extend the freshness of late autumn Chinese cabbage, the packaging and loading effects on the quality were investigated during cold storage. Judging from overall quality during storage period, late autumn Chinese cabbage could be stored by 3 months at 0$\^{C}$ cold storage. However, late autumn Chinese cabbage was not acceptable for long-term storage because of its marketability and the storage cost. Among 3 packaging methods(PP-net, carton and plastic container) for stored Chinese cabbage, plastic container and carton were more effective than PP-net packaging for the freshness prolongation. Gas composition in the plastic bags during storage was not significantly different among packaging conditions and O$_2$ and CO$_2$ concentrations were 13∼18% and 0.75∼7.48%, respectively, MAP with plastic film was effective for the quality retention because of low oxygen composition and high humidity condition in the bags.

• Research in Plant Disease
• /
• v.12 no.3
• /
• pp.278-283
• /
• 2006

The effect of calcium cyanamide($CaCN_2$) on suppression of clubroot of Chinese cabbage was evaluated in the fields infested with Plasmodiophora brassicae at National Institute of Highland Agriculture, Pyeongchang, Korea, from 2002 to 2003. Calcium cyanamide was found to be more effective in reducing disease severity than flusulfamide dust powder. The optimal dosage of calcium cyanamide for control of clubroot of Chinese cabbage was 61 kg/10a. When calcium cyanamide was incorporated into soil at 5, 10, 15 and 20 days before planting(DBP), maximum disease suppression was obtained in the plot with calcium cyanamide, applied 5DBP. The fertilizer property of calcium cyanamide as a nitrogen fertilizer was also investigated by comparing with urea on cv. CR Gangta, a resistant variety of Chinese cabbage. The nitrogen uptake in calcium cyanamide treatment(17.6 kg/10a), was not significantly different from that of urea(17.8 kg/10a). These results indicated that calcium cyanamide could be used as a soil disinfectant as well as a nitrogen fertilizer.

• The Korean Journal of Pesticide Science
• /
• v.13 no.2
• /
• pp.111-116
• /
• 2009

Juvenile hormone (JH) is an insect hormone mediating immature metamorphosis and adult reproduction. It also mediates immune responses to suppress hemocyte behavior, which is, however, activated by ecdysteroid. This study investigated an effect of a commercial pyriproxyfen (a JH agonist) formulation on a cellular immune response of the diamondback moth, Plutella xylostella, and analysed its mixture with Bacillus thuringiensis (Bt) in insecticidal potency. The commercial pyriproxyfen formulation significantly suppressed hemocyte-spreading behavior at low doses as did in pyriproxyfen technical grade. When the commercial pyriproxyfen formulation was mixed with Bt, Bt toxicity was significantly increased against P. xylostella larvae in laboratory. The mixture effect was then confirmed in field cultivating cabbage infested with P. xylostella larvae. The mixture showed a significantly enhanced mortality and reduced effective lethal time, compared to only Bt treatment.

• Korean journal of applied entomology
• /
• v.50 no.3
• /
• pp.215-220
• /
• 2011

This study aimed to estimate control thresholds for managing common cutworm, Spodoptera litura Faricius (Lepidoptera: Noctuidae) at different larval densities and growth stages of Chinese cabbage in field conditions. The percent yield reduction (Y) of Chinese cabbage infested by different densities of S. litura (X, no. of larvae/100 plants) for three weeks were estimated by Y=-21.85X+1300 (R2=0.997) 5 days after transplanting and Y=-12.1X+1382 (R2=0.998) 20 days after transplanting. Based on the relationships between the densities of S. litura larvae and the yield index of chinese cabbage, the number of larvae (2nd to 3rd instar) which caused 5% loss of yield was estimated as 2.9/100 plants 5 days after transplanting, and 5.6/100 plants 20 days after transplanting.

• Korean journal of applied entomology
• /
• v.54 no.4
• /
• pp.303-310
• /
• 2015

The diamondback moth, Plutella xylostella, overwinters in some protected areas in Korea. Using a sex pheromone trap, the adults were monitored since the occurrence of the overwintering populations. In Andong, P. xylostella exhibited four adult peaks in a year. Biological characters, such as cold tolerance, insecticide susceptibility, and developmental rate, were analyzed and showed a significant variation among different local overwintering populations. Population genetic variation was assessed with molecular markers, in which the initial high genetic variation among the overwintering populations decreased with the progress of seasons. These results suggests that there may be a significant migration of P. xylostella to decrease the genetic variation among the different local populations that are different in biological characters.