• Korean Journal of Remote Sensing
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• v.34 no.4
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• pp.681-692
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• 2018

This study was performed to select the significant wavelengths for predicting the chlorophyll content of grafted cucumber seedlings using hyperspectral images. The visible and near-infrared (VNIR) images and the short-wave infrared images of cucumber cotyledon samples were measured by two hyperspectral cameras. A correlation coefficient spectrum (CCS), a stepwise multiple linear regression (SMLR), and partial least squares (PLS) regression were used to determine significant wavelengths. Some wavelengths at 501, 505, 510, 543, 548, 619, 718, 723, and 727 nm were selected by CCS, SMLR, and PLS as significant wavelengths for estimating chlorophyll content. The results from the calibration models built by SMLR and PLS showed fair relationship between measured and predicted chlorophyll concentration. It was concluded that the hyperspectral imaging technique in the VNIR region is suggested effective for estimating the chlorophyll content of grafted cucumber leaves, non-destructively.

• The Korean Journal of Pesticide Science
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• v.4 no.2
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• pp.37-43
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• 2000

Effects of silicon application on development of colonies of Sphaerotheca fuliginea were examined. Cucumber plants were applied with nutrient solutions amended with different concentrations of soluble silicon and selected leaves were inoculated with known concentrations of conidia of the pathogen. Colony number per leaf, colony area per leaf, and germination rate of conidia of S. fuliginea collected from the inoculated leaves were reduced as silicate concentrations in the nutrient solutions increased from 0.05 to 4.10 mM. The increase in resistance of plants to mildew infection was apparently due to silicate accumulation in leaves, and there was no correlation between cation or ionic strength effects and the silicate treatments. Silicate treatment in growth medium remarkably suppressed powdery mildew development on cucumber. Colonies of mildew fungus were visible with over approx. 38.3% of the mature leaf surface, while that of the leaves in high Si plants was 2.3% observed at 51 days after transplanting. No significant differences were observed between 1.7 mM and 3.4mM silicate treatments. Conidial germination rates were significantly reduced by increasing Si amendments. Conidial germination ranged from 14.7 to 20.3% for plants grown in low Si solution(<1.40 mM), and from 9.0 to 12.4% for plants grown in high Si solution(>1.8 mM). Foliar applications of Si with ${\geq}$ 17.0 mM decreased the number of powdery mildew colonies. Persistence of Si foliar sprays effects on cucumber demonstrated that the 17 mM Si spray applied 4 days before inoculation with S. fuliginea reduced mildew colony formation. The relationship was positive and linear.

• Research in Plant Disease
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• v.12 no.3
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• pp.221-225
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• 2006

Cucumber mosaic virus(CMV) and Broad bean wilt virus 2(BBWV2) were isolated from Gentiana scabra plants showing typical mosaic and yellowing symptoms. When the inoculum of mosaic symptom propagated in Nicotiana benthamiana was inoculated to primary leaves of Vigna sinensis, the local lesions of different types was developed. Type one produced a small necrotic spot(SNS) of pinpoint type, while the other one showed a large necrotic spot(LNS) of halo type. LNS on primary leaves of V. sinensis was also induced by inoculum from yellowing symptom on G scabra. Single lesion from SNS induced a typical mosaic symptom on N. Benthamiana. On the other hand, LNS produced a chlorotic ring symptom on inoculated leaves and mosaic plus necrotic ringspot on upper leaves of N. benthamiana. An isolate of CMV from SNS and BBWV2 from LNS were detected by using dsRNA analysis, RT-PCR and agar gel double-diffusion test. Thus, our results should provide a tool of a simple method for discrimination from mixed infected plants by CMV and BBWV2.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.272-279
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• 2003

This study was performed to develop a more rapid and simple nutrient diagnosis method of plants than the conventional leaf analysis method. Cucumber (Cucumis sativus L. cv. jangil banbaek) was planted in the mixed media produced by mixing perlite and rock wool at 1:1 (v/v) ratio. The Yamazakki nutrient solution for cucumber was supplied to the media using micro-drip irrigation system. Experimental plots were consisted of no fertilization, deficient fertilization, adequate fertilization, and surplus fertilization for N, P and K. Specific color difference sensor value (SCDSV) measured by chlorophyll meter was closely related to total-N concentration in leaves measured by the conventional method. Nitrate, $PO_4$ and K concentration in petiole sap measured by test strips showed a significant relationship with total-N, P and K concentration in leaves. Linear regression equations between $NO_3$, $PO_4$ and K concentration in petiole sap and total-N, P and K concentration in the leaves were prepared. Optimum levels of $NO_{3}$, $PO_{4}$ and K in petiole sap were obtained by plugging the optimum concentrations of total-N, P and K in the leaves by other researchers into the equations. In conclusion, the SCDSV measured by chlorophyll meter and the concentration of $NO_3$, P and K in petiole sap measured by the test strips would be suitable for rapid estimation of plant nutrient status.

• Journal of Bio-Environment Control
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• v.8 no.4
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• pp.265-274
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• 1999

This experiment was carried out to investigate the effect of container size and substrate volume on the growth and fruit yield of hydroponically grown cucumber(Cucumis sativus L.) plants. Seeds were sown in plug tray filled with coir dust on Feb. 13, 1998. Seedlings with 5 to 6 true leaves were transplanted in $2{\ell},\;4{\ell},\;6{\ell},\;8{\ell}\;and\;10{\ell}$ plastic pots filled with perlite. Cucumber fruits were harvested with 1 to 2 days interval, and fresh weight, number of normal and malformed fruit were recorded. Plant height, stem diameter, number of leaves and leaf area were highly depended on the container size. Total fresh weight and the number of fruit were increased with increasing container size. NAR(net assimilation rate) and CGR(crop growth rate) increased also with increasing the container size. Optimum container size for hydroponically grown cucumber plant using perlite was recommended as $8{\ell}$ per plant.

• Applied Biological Chemistry
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• v.44 no.1
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• pp.7-11
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• 2001

The distribution of procymidone in a small vinyl house containing cucumber plants or mimic plants was investigated after application of smoke generator. The deposition of procymidone on glass plate and filter paper was significantly similar to that on cucumber leaves, so that glass plate and filter paper could be substituted for cucumber leaves on deposition studies. The deposition of procymidone was proportional to the horizontally projected area of surface; the deposition on the horizontal surface was maximal, and the deposition was minimal for the perpendicular surface. The amount of deposition on the backside of leaf was less than 5% compared to that on the horizontal surface of leaf. The height of leaf from the floor was not a significant factor influencing on the deposition of procymidone whether leaves were overlapped or not. However, the deposition of procymidone on the overlapped leaves was relatively less than that on the unoverlapped leaves. And the deposition difference depending on the distance between leaves was not observable. Overall, the deposition of procymidone was proportionally increased with the application rate of smoke generator, but the deposition was inversely related to the sum of the total horizontal leaf area of mimic plants and the surface area of floor.

• Journal of Bio-Environment Control
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• v.13 no.4
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• pp.245-250
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• 2004

To investigate the effect of early-morning heating periods on growth and yield of cucumber and heating load in a greenhouse cultivation, three additional heating periods (0, 1 and 2 hours) were compared to rise temperature from $12^{\circ}C\;to\;16^{\circ}C$ in the early-morning. Leaf temperature just before opening the thermal screen was $3.3^{\circ}C\;and\;4.1^{\circ}C$ higher in the 1 and 2 hour heating compared to that in the control (0 hour heating), respectively. Photosynthetic rate, conductance to $H_2O$ and transpiration rate of cucumber leaves were the highest in the 2 hour heating, and the lowest in the control. However. the difference between the 1 hour and 2 hour heating was not significant. Inorganic element content in cucumber leaves was not significant among the treatments of duration. Initial growth after planting of cucumber was greater in the 1 and 2 hour heating than that in the control. Yield increased by $11\%\;and\;15\%$ in the 1 hour and 2 hour heating compared to that in the control. respectively. Fuel consumption for heating increased by $12\%\;and\;22\%$ in the 1 hour and 2 hour heating compared to that in the control, respectively. Considering in the yield and fuel consumption for heating. 1 or 2 hours of early morning heating could be effective in temperature management for cucumber in a greenhouse cultivation.

• Research in Plant Disease
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• v.14 no.2
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• pp.138-141
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• 2008

Cucumber is high valued cash crop, for it is grown during the winter season in plastic house. Recently, virus disease spread widely in cucumber growing area and cause severe income loss. Therefore, occurrence of virus disease on cucumber were surveyed from 2004 to 2006 in Sangju and Gunwi area, Gyeongbuk province. The rate of plastic house which has infected plants was $55.0{\sim}88.6%$. Infection rate was the highest at Sangju in 2006 than others and ranged from 15 to 90.0% per plastic house. The 217 samples showing virus symptom were analyzed by RT-PCR using appropriate detection primer. Zucchini yellow mosaic virus(ZYMV) has the highest infection rate(detected over 85%) and followed by Cucumber green mottle mosaic virus(CGMMV). But Watermelon mosaic virus-2(WMV-2) was not detected in our survey. Therefore, we conclude that ZYMV is major pathogene of virus disease on cucumber. ZYMV induced chlorosis and severe mosaic on the leaves and distortion on the surface of fruits.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.148.2-149
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• 2003

Cucumber fruit mottle mosaic tobamovirus (CFMMV) causes severe mosaic symptoms with yellow mottling on leaves and fruits, and occasionally severe wilting of cucumber plants. No genetic source of resistance against this virus has been identified. The genes coding for the coat protein or the putative 54-kDa replicase were cloned into binary vectors under control of the SVBV promoter. Agrobacterium-mediated transformation was peformed on cotyledon explants of a parthenocarpic cucumber cultivar with superior competence for transformation. R1 seedlings were evaluated for resistance to CFMMV infection by lack of symptom expression, back inoculation on an alternative host and ELISA. From a total of 14 replicase-containing R1 lines, 8 exhibited immunity, while only 3 resistant lines were found among a total of 9 CP-containing lines. Line 144 homozygous for the 54-kDa replicase was selected for further resistance analysis. Line 144 was immune to CFMMV infection by mechanical and graft inoculation, or by root infection following planting in CFMMV-contaminated soil. Additionally, line 144 showed delay of symptom appearance following infection by other cucurbit-infecting tobamoviruses. Infection of line 144 plants with various potyviruses and cucumber mosaic cucumovirus did not break the resistance to CFMMV. The mechanism of resistance of line 144 appears to be RNA-mediated, however the means is apparently different from the gene silencing phenomenon. Homozygote line 144 cucumber as rootstock demonstrated for the first time protection of a non-transformed scion from soil inoculation with a soil borne pathogen, CFMMV.

• Research in Plant Disease
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• v.12 no.3
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• pp.226-230
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• 2006

Cucumber mosaic virus(CMV) was occurred on red pepper showing vein chlorosis or vein necrosis with the incidence rate of 52% from 62 specimens collected in natural fields. Among 32 samples infected with CMV, the specimens of 22 red pepper leaves showing vein chlorosis were infected singly with CMV-VCH. CMV-VCH induced vein chlorosis on the inoculated leaves, and vein banding and vein necrosis on the upper leaves of Nicotiana glutinosa, and then killed after showing bud necrosis. The typical symptoms of vein banding, malformation and blister were produced on the upper leaves of Nicotiana benthamiana and N. tabacum 'Ky-57' without symptoms on the inoculated leaves. The commercial cultivars of 'Bugang', 'Manitta' and 'Gwariput' were shown the typical symptom of vein chlorosis by the mechanical inoculation of CMV-VCH. CMV-VCH was detected specifically by RT-PCR. Virus particles of CMV-VCH were isometric shape having 30 nm diameter. Ultraviolet absorption of purified CMV-VCH was maximum at 260 nm and minimum at 242 nm. The ratio of A260/A280 was 1.71. CMV-VCH had the single nucleo-protein having the molecular weight of 24.5 kDa.