양배추가루진딧물을 다채(Brassica campestris var. narinosa)를 기주로 하여 7단계 온도(15, 18, 21, 24, 27, 30, 33℃), 습도 65±5%, 광주기 16L:8D에서 조사하였고, 이를 이용하여 생명표를 작성하였다. 성충수명은 21℃(14.9일)를 기준으로 고온과 저온으로 갈수록 감소하는 경향을 보였고, 산자수는 24℃에서 58.5마리로 가장 많았다. 성충 1마리의 일일 산자수는 24℃가 4.7마리, 27℃가 4.5마리로 비슷하였고, 고온과 저온으로 갈수록 감소하는 경향을 보였다. 양배추가루진딧물의 생명표를 작성한 결과 순증가율(Ro)은 24℃에서 가장 높게 나타났고, 18℃와 30℃에서 급격히 감소하였다. 내적자연증가율(rm)은 27℃에서 최고치인 0.356을 나타냈고, 기간증가율(λ)은 27℃에서 가장 큰 1.427을 나타냈다. 평균세대기간(To)은 온도가 올라감에 따라 짧아져 30℃에서 가장 짧았다.

This study was estimated for cabbage aphid, Brevicoryne brassicae in Brassica campestris L. var. rapa (L.) Hartm. in order to institute of Economic injury levels(EILs). B. brassicae was innoculated on April 29, in differently 0, 5, 10, 20 and 40 adults per ten plant, respectively. After inoculated of B. brassicae, the density was increased until harvest ing gradually in all plots except non innoculate plot. and Higher inoculation density were increased higher than lower inoculation density. Percentage of damage leaf was higher in plots with higher initial aphid density than in plots with lower initial aphid density. And the leaf weight of commodity were decreased in higher initial aphid density. The decreasing rates of leaf weight of commodity was increased with increasing initial aphid density. The relationship between initial B. brassicae densities and the decreasing rates of leaf weight of commodity was well described by a linear regression, Y=0.8416X-3.5147, R2=0.94. Based on the relationship, the number of adults per 10 plant which can cause 5% loss of yield was estimated to be approximately 10.1. And EILs was estimated to be approximately 1.0 adults/plant in late April.

An experiment was conducted to find out the effect of brushing treatment during cultivation on the postharvest quality of the baby leaf vegetable, specifically tah tasai Chinese cabbage (Brassica campestris var. narinosa). The effect of mechanical brushing during cultivation on the postharvest quality was determined in terms of the quality changes in weight loss, gas partial pressure, leaf color, and appearance during storage using a 30-㎛-thick polypropylene film at 16℃. The brushing treatment included brushing with A4 paper back and forth 50 times a day. The study revealed that the growths on the brushing-treated plant group were less than those on the control group. The structure of the leaf tissue of the brushing-treated plant also tended to be less compact than that of the non-treated plant. The brushing treatment resulted in less growth and denser plant tissues as well as in differences in the gas O2 consumption and CO2 accumulation after packaging. For the gas partial pressure, the O2 consumption and CO2 accumulation of the brushing-treated plant tended to be less than those of the non-treated plant. There were no differences, however, between the brushing-treated plant and control groups in the SPAD value and appearance. The study results also suggested that after packaging, the effects of the brushing treatment during cultivation on the quality of the tah tasai Chinese cabbage baby leaf vegetable was not significant. As such, it is recommended that effective post-harvest methods of improving the product quality of the baby leaf vegetable be further investigated.

The effect of the packing methods for enhancing the shelf life and improving the postharvest quality of the tah tasai Chinese cabbage baby leaf vegetable was studied during storage. Fresh baby leaf vegetables were packed in four commercial packaging types: (1) a non-perforated bag with a 0.03-mm oriented polypropylene (OPP) film; (2) a perforated bag with 1.0-mm-diameter holes on an OPP film; (3) a 0.40-mm polyethylene terephthalate (PET) container with a hinged lid; and (4) an expanded polystyrene (EPS) tray wrapped with a 0.02-mm polyvinyl chloride (PVC) film. The quality parameters, such as the weight loss, moisture content change, color difference, and appearance of the baby leaf vegetables were investigated. The baby leaf vegetables in the PET container and in the non-perforated OPP film bag showed relatively low weight loss, high moisture content, and good external appearance compared to those in the EPS tray and in the perforated OPP film bag during limited storage periods, at 16oC.ThePETcontaineralsoprotectedthebabyleafvegetablesfromphysicaldamage.Thestudyresultswillenabletheselectionofabetterpackagingsystemforextendingthefreshnessandincreasingthemarketabilityofbabyleafvegetables.

The demand of packaged baby leaves has been increased for its convenient use as fresh-cut produce. This investigation was aimed to explore the effects of different sanitizers on the quality parameters of 'Tah Tasai' Chinese cabbage (Brassica campestris var. narinosa) baby leaves. Thirteen days old baby leaves were harvested and washed in tap water (TW), 100 ppm chlorine solution (Cl), 2 ppm ozonated water (), 15 ppm chlorine dioxide solution () and washing with 0.2% citric acid solution followed by 50% ethanol spray (CA+Et). The samples were then packaged in 50 polyethylene bags and stored at for 10 days. Off-odor of packaged baby leaves was not detected during storage. There was no significant difference in color parameters among the treatments. Samples treated with showed substantially higher electrolyte leakage throughout the storage. This treatment also rendered a higher accumulation of in the packages. Samples treated with Cl and CA+Et maintained good overall visual quality with higher scores compared to that of and . Although Cl treatment showed lower number of total aerobic count at the beginning of storage, citric acid in combination with ethanol treatment was more effective until the end of storage. The combined treatment also showed comparatively lower coliform plate count. This result indicates that citric acid wash followed by ethanol spray could be an alternative to chlorine for environment friendly sanitization of baby leaves.

This study was conducted to examine morphological characteristics and the content of cell wall polysaccharides of Brassica campestris var. pekinensis(baechu). First of all, the variety of scientific name and naming of parts of baechu in the literatures of kimchi showed, which will unify marks. So, we propose not so much mid-rib and leaf blade of baechu leaf as white part and green part, respectively. On the other hand, the forms of vessel elements of white part in baechu consist in ring, sclariform and reticulate thickening. The proximate compositions and contents of cell wall polysaccharides of baechu has significant differences between its cultivars. The cell wall pectin from baechu exhibited four peals with molecular weights of 2,000,000, about 100,000 and less than 10,000 by gel filteration chromatography and hemicellulose did two peaks with molecular weights of 2,000,000 and 10,000.