• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.22-27
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• 1984

The effects of solarization on the suppression of soilborne plant pathogen and the growth promotion of cucumber plants were examined in artificially infested soil by vinyl mulching and not mulching from July 25 to August 25, 1983. During the solarization period, the highest temperatures were $58^{\circ}C,\;45^{\circ}C,\;and\;42^{\circ}C$, at 5cm, 15cm, and 25cm of soil depth respectively. The inoculum of cucumber wilt pathogen, Fusarium oxysporum f. sp. cucumerinum, was mixed with soil 30cm deep and saturated with water. The pathogen was completely killed after 30dys of solarization in 5cm soil depth and 98 percent of inoculum was eliminated in 15cm soil depth. But the survival rate of the fungi in 25cm soil depth of solarized plot did not show significant differences compared with those in nontreated plot in 5cm and 15cm depth. Although some of the pathogenic fungi might survive from solarized soil in 15cm and 25cm depth, the ability of microconidia production was reduced significantly The number of microconidia grown on Komada's medium in isolates the primary colonies from solarized soil was less than that in isolates from nontreated soil approximately by one fourth. The first subcultured solates from the solarized soil grown on potato dextrose agar also produced a small amount of microc. onidia compare with that of subcultured isolates from nontreated soil. Cucumber seedlings planted in the soil collected from solarized plot grew much better than that in the soil from nontreated plot at any of soil loved, especially in 5cm of soil depth. And the fruits harvested from cucumber plants grown in the solarized plot were more in number and leavier in weight than that from nontreated plot. Besides the typical symptom development, significant growth suppression wvas recognized with increase of inoculum density of F. oxysporum f. sp. cucumerinum at early stage of cucumber seedlings in steam sterilized soil.

• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.312-316
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• 2012

This study evaluated the effect of polyolefine greenhouse covering film on growth of lettuce and cucumber. The growth of lettuce and cucumber plants under conventional film (polyethylene plus ethylenevinyl acetate, PE + EVA) and polyolefine (PO) film were evaluated in a greenhouse. The physical qualities of PO film, such as tensile strength and tear strength, were stronger than conventional PE + EVA film. PO film showed 4% higher transmission performance in photosynthetic active radiation (PAR) than PE + EVA film. The average day and night temperature in greenhouse under PO film were $1.5^{\circ}C$ and $0.8^{\circ}C$ higher but there was no significant difference in relative humidity compared with conventional film. Chlorophyll content of lettuce and cucumber plants grown under PO film were higher than conventional film. Growth characteristics; plant height, leaf area, fresh weight and dry weight of cucumber was shown better for PO film. The yields of cucumber and lettuce was increased 14.0% and 13.6% respectively, when the crops were grown under PO covering film greenhouse.

• 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.

• The Korean Journal of Pesticide Science
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• v.12 no.2
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• pp.118-126
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• 2008

In order to find the best compositions of the dimethomorph formulation containing fatty alcohol ethoxylate surfactants as an activator adjuvant and recommend the good management way of the formulations to allow an intended uptake rate, factors affecting foliar uptake of active ingredients into cucumber were investigated and compared each other. Among tested, the most important factors were air temperature in which plants were located after spraying of aqueous formulations containing activator adjuvant, and deposit of wax on the leaf surface of cucumber. Dimethomorph uptake was found to be increased by sunlight. When aqueous formulations had long-polyethoxylated fatty alcohol surfactants, the relative humidity of the room in which the plants were located after spraying with the formulations did not severely influence the foliar uptake. Maintaining a mild temperature and avoiding too strong sunlight after spraying with dimethomorph formulations were found to be resonable management strategies.

• Research in Plant Disease
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• v.18 no.1
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• pp.57-61
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• 2012

In March 2010, grafted cucumber cultivated in the greenhouse showed a severe rot on crown resulting yellowing and wilting of the leaves. The symptoms of naturally infected plants showed dark brown, watersoaked lesions at the base of the stem. The fungus produced mass of white mycelium and yellow to orange spores in necrotic lesions on dead and dying plants. Fungus was isolated from rotted tissues of the crown and root. On the basis of morphological characteristics, ITS sequence and pathogenicity tests, the isolate was identified as Fusarium solani f. sp. cucurbitae. This is the first report of the crown and foot rot of grafted cucumber caused by F. solani f. sp. cucurbitae in Korea.

• 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.

• The Plant Pathology Journal
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• v.21 no.2
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• pp.167-171
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• 2005

We isolated the Cucumber green mottle mosaic virus(CGMMV) particles from watermelon leaves and designated as CGMMV-HY1 as a watermelon isolate and attempted to characterize the pathogenic isolate responsible for such an epidemic in watermelon and also to monitor dominant viral isolates in greenhouse. The watermelon plants infected with CGMMV generally showed mottle mosaic, mosaic, growth stunting, necrosis and deformed fruit. The reactions of indicator plants to CGMMV-HY1 were the local lesions on Nicotiana tabacum cv. White Burley, Nicotiana tabacum cv. Samsun, and Chenopodium amaranticola, and the mosaic symptoms only on Cucumis sativus, but the CGMMV-HY1 did not infect Nicotiana sylvesytis, Datura stramonium, Chenopodium quinoa, and Petunia hybrida. Purified virus particles were rod-shaped and about 300 nm long. The coat protein (CP) of purified CGMMV-HY1 was single band with molecular weight of about 16.5 kDa which was confirmed by western blot analysis probed with monoclonal antibody of CGMMV-HY1. The genomic and subgenomic RNAs of 6.4 kb and 0.75 kb were revealed by the electrophoresis on 1.2% formaldehydedenatured agarose gel. Viral and complementary CGMMV-specific primer sets were designed for spanning the genome using previously reported CGMMV sequences. A 464bp of CP gene of CGMMV-HY1 was amplified by RT-PCR and cloned into PGEM-T easy vector. The nucleotide sequence of CP gene of CGMMV-HY1 shared 98%, 99%, and 100% identities with that of CGMMV strains W, KOM, and KW respectively. Based on these results, we identified CGMMV-HY1 as a CGMMV isolate of watermelon, a member of Tobamovirus.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.301-310
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• 1994

This experiment was conducted to test the fungicidal activity of extracts from 50 medicinal plants to powdery mildew (Sphaerotheca fulinginea) and identify the bioactive substances. Among the medicinal plants tested, the water extract of Rheum undulatum was the most effective in spore germination inhibition, which inhibited by 100% at 200-fold dilution. Also, 50-fold dilution of water extract, 100-fold dilution of alcohol extract, 500-fold dilution of crude extract from Rheum undulatum and even 1000-fold dilution of reference chemical inhibited powdery mildew of cucumber more than 60%. 500-fold dilution of crude extract inhibited powdery mildew of cucumber 100% by twice spray treatment. There was phytotoxcity at the 100-fold dilution, but was not recognized this injury at the 500-fold dilution of crude extract. From our research to identify bioactive substance using HPLC, GLC and Mass spectrum analysis, it indicated that Rheum undulatum extract contained tentatively 1,8-dihydroxy-3-methyl-9,10-anthracenedione and 1,8-dihydroxy-3-methoxy-6-methyl-9,10-anthracenedione.

• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.400-405
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• 2006

Waste nutrient solution(WNS) using non-recycled hydroponics for melon increased contents of $NO_3$-N and cataions, such as, Ca, K, while anions except $NO_3$-N were decreased slightly as the musk melon plants grew. pH and EC of WNS were maintained 5.7$\sim$7.0, 2.0$\sim$2.2 $dS{\cdot}m^{-1}$, respectively. The musk melon plants cultivated by fertigation using WNS showed longer plant height and root length, and higher chlorophyll content than that grown by hydroponics. The fruit weight of musk melon grown by fertigation using WNS were 417.1 g heavier than that cultivated by hydroponics and soluble solids contents of musk melon fruit cultivated by fertigation using WNS was $13.3^{\circ}Brix$, that was $1.4^{\circ}Brix$ higher than that grown by hydroponics. While the growth of cucumber plants and size of cucumber fruits were not different between in fertigation using WNS and hydroponics, total yields and marketable fruit percentage showed more in fertigation using WNS than in hydroponics.

• The Plant Pathology Journal
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• v.16 no.6
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• pp.306-311
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• 2000

A new strain of Cucumber mosaic virus (CMV) from easter lily (Lilium longiflorum), Ly2-CMV, was identified and compared to the well-characterized Mf-CMV (subgroupⅠ) and LS-CMV (subgroupⅡ) by host reaction in several indicator plants, dsRNA analysis, serological property, RT-PCR analysis, restriction enzyme profile of the PCR products and nucleotide sequence of coat protein (CP) gene. Remarkable differences in symptoms of Ly2-CMV were found between Mf-CMV or LS-CMV in tobacco plants and Datura stramoinium. Ly2-CMV induced small necrotic ringspots on the inoculated leaves of Nicotiana tabacum cvs. Xanthi nc and Burley 21 and D. stramonium, and failed to infect these species systemically. Of the indicator plants tested, N. benthamiana only reacted with systemic infection by inoculation of Lr2-CMV. In experiments of dsRNA analysis, serology and RT-PCR of CP gene, Ly2-CMV was come within subgroupⅠ CMV. However, restriction enzyme analysis of the PCR products using MspⅠ showed that Ly2-CMV was distinct to Mf-CMV. The CP gene of Ly2-CMV contains 657 nucleotides, and the nucleotide sequence is similar to that of Mf-CMV. There is also a high degree of conservation between their putative gene products in Ly2-CMV and Mf-CMV, with five amino acid changes in the 218 amino acids of the CPs.