• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.223-227
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• 2007

This study was carried out to establish the reasonable level of nitrogen (N) fertilization based on soil nitrate nitrogen $(NO_3-N)$ content for cucumber (Cucumis sativus L.) under plastic film house. Cucumber plants were cultivated with standard and free N fertilization in eight soils which had various amount of $NO_3-N$ ranging from 67 to 343 mg/kg. The yield of cucumber was in the range of 1006 to 2369 g/plant depending on the nitrogen supplying capability of soils. The amount of $NO_3-N$ in the soil was negatively correlated with agronomic efficiency (AE) and N use efficiency (NUE). The critical level of soil $NO_3-N$ content for cucumber in N free fertilization was found to be about 260 mg/kg in Cate-Nelson analysis of variance between soil $NO_3-N$ and AE or NUE. Also the same critical soil $NO_3-N$ content was found in the yield and amount of N uptake of cucumber under N free fertilization. A standard N fertilization was required when soil $NO_3-N$ content was below 70 mg/kg. The optimal application rate of N fertilizer for cucumber in the soils containing $NO_3-N$ between 260-70 mg/kg could be recommended by the equation Y=-1.032X+269.2 (Y: N fertilization rate, kg/ha; X : soil $NO_3-N$ content mg/kg).

• Mycobiology
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• v.30 no.3
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• pp.175-179
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• 2002

A study on comparative efficacy and in vitro activity of fresh cow urine and cow dung for controlling Sclerotinia rot caused by Sclerotinia sclerotiorum of cucumber was carried out following mycelial growth inhibition test, treated and untreated sclerotia with these organic matters at different days of incubation. Results showed that cow urine suppressed more effectively the mycelial growth even after 5 days of incubation in comparison to cow dung. The highest inhibition 75.9% of mycelial growth was recorded in cow dung potato dextrose agar(CUPDA) after 3 days of incubation and least 22.7% was in cow dung potato dextrose agar(CUPDA) after same days of incubation. Mycelial growth from sclerotia of S. sclerotiorum was also influenced by PDA medium mixed with cow urine and cow dung. After 6 days of incubation in CUPDA mycelial growth was only 12.9 mm whereas in CDPDA and PDA the corresponding growth at the same time were 65.8 mm and 80.0 mm. Treated sclerotia of the selected fungus with cow urine had a very effective role on suppression of mycelial growth than that of untreated one. No mycelial growth was observed up to 4 days in treated sclerotia with cow urine. After 5 days only 0.9 mm mycelial growth was measured in treated sclerotia, while in case of untreated sclerotia the growth was 42.6 mm. Application of cow urine and cow dung on growing plants inoculated with the pathogen at different concentrations also proved their inhibitive effects.

• The Plant Pathology Journal
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• v.18 no.1
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• pp.6-11
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• 2002

An isolate of Cucumber mosaic virus (CMV), PaFMl-CMV causing malformation on the fruit of paprika (Capsicum annuum var, grossum) was characterized based on biological reactions, serological relationships, and partial nucleotide sequence analyses. PaFMl-CMV was distinguishable from other isolates of CMYI Mf-(subgroup I) and LS-CMV (subgroup II), in terms of its reactions to some host plants. Polyclonal antibody against PaFMl-CMV showed homologous antigenic relationship with LS-CMV, however, the antibody formed a spur between PaFMl- and Mf-CMV, In the comparison of molecular size of dsRNAs of PaFMl-CMV with Mf- and LS-CMV, PaFMl-CMV had a slightly smaller RNAl and larger RNA2, RNA3, and RNA4. When the CDNA product of PaFMl-CMV coat protein (CP) gene was digested with some restriction enzymes, the fragment pattern was identical with that of LS-CMV The nucleotide and amino acid sequences of PaFMl-CMV CP gene were 99.5% and 98.6% identical with LS-CMV respectively. The data indicate that PaFMl-CMV belongs to subgroup II of CMV, which is the first report in Korea.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.88-94
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• 2013

As the results of analysis that are applying a heat pump using underground water as heat source of facility horticulture house, temperature change in house, growth of cultivated plants and the crop characteristic, the conclusion can be acquired as follows. It was possible to maintain the chamber temperature through operating heat pump with setting goal temperature at $16^{\circ}C$ and temperature variation at ${\pm}3^{\circ}C$. And cooling and heating coefficient of performance in heat pump system are different from setting room temperature and operation condition of equipment, totally in case that the setting temperature in house is low, the coefficient of performance and the in case that temperature departure is low. In case that the house does not heated, the result of the growth characteristic of cucumber planted last 50days is that cucumber grown in house equipped with heat pump is the most favorable growth characteristic due to maintaining a constant room temperature. After 90 days, the quantity and weight cucumber harvested in each house are averagely 9.8%, 13.1% increase and more heavy weight respectively. So it is researched that crop characteristic is superior.

• Journal of Bio-Environment Control
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• v.13 no.2
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• pp.96-101
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• 2004

This study was conducted to determine the daily application rate and amount of N and K with fertigation during different growth stages in semi-forcing culture of cucumber plants (Cucumis sativus L. cv. Eunseongbaekdadagi). The diagnostic criteria for N and K also investigated based on petiole sap analysis. The dry weight increased slowly until 30 days after transplanting. The highest dry weights were observed at 60 days after planting, then it decreased. As the plant grew, the contents of N and K in the petiole sap and fruit of cucumber decreased. The daily uptake of N and K were highly correlated with the growing days. The $NO_3$ concentrations in petiole sap were in the range from 3,500 to 4,500 mgㆍ$L^{-1}$ in the early growth stage, but those were in the range from 2,000 to 3,000 mgㆍ$L^{-1}$ after then. However, K concentration in petiole sap were in the rang from 5,000 to 7,000 mgㆍ$L^{-1}$ The fluctuation in petiole sap concentration of K was severe in the monthly fertigation and moderate in the daily fertigation. The fertigation by petiole sap diagnosis forced EC of soil to be low and yield to increase compared to the control.

• Journal of Bio-Environment Control
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• v.9 no.4
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• pp.185-192
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• 2000

This study was conducted to develop mathematical model of respiration rate of cucumber plant under varying environmental conditions. 8.55% of gross photosynthesis of individual cucumber plant was used as respiration. Growth respiration coefficient was estimated as 0.0935. Maintenance respiration rate was estimated as 0.00158g CH$_2$g$^{-1}$ .h$^{-1}$ at 24$^{\circ}C$ of air temperature and it increased exponentially as air temperature became higher. Respiration rate decreased poportionally as content of storage carbohydrate became lower. Ion uptake respiration rate of roots was estimated as 0.6648g C$H_2O$.(gN)$^{-1}$ .

• Journal of Environmental Science International
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• v.11 no.11
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• pp.1173-1181
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• 2002

The present study was undertaken to investigate the effect of low temperature and salicylic acid(SA) on the chilling tolerance of acclimated and nonacclimated cucumber(Cucurmis sativus L.) seedlings. The acclimation phenomenon was characterized in chilling-sensitive cucumber seedlings and found to have a significant effect on the survival and shoot dry weights. The injuries experienced by the acclimated seedlings in the third leaf stage were on average smaller by half than those experienced by the nonacclimated seedlings. Chilling also caused a large increase in the free proline levels, regardless of the acclimation status. Exogenous treatment with SA(0.5mM) resulted in improved growth and survival of the nonacclimated chilled seedlings, indicating that SA induced chilling tolerance and SA and acclimation had common effects. The application of cycloheximide in the presence of SA restored the acclimation-induced chilling tolerance. The elevated proline level observed in the cold-treated and SA-treated plants was more pronounced in the light than in the dark at a chilled temperature, indicating that endogenous proline may play a role in chilling tolerance by stabilizing the water status in response to chilling. From these results it is suggested that SA provided protection against low-temperature stress by increasing the proline accumulation, and pre-treatment with SA may induce antioxidant enzymes leading to increased chilling tolerance.

• The Plant Pathology Journal
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• v.19 no.4
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• pp.210-216
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• 2003

This study examined the existence of genetically diverse population of Cucumber mosaic virus (CMV), known as quasispecies, from lily, Nicotiana benthamiana and from purified virions. Based on the conserved sequences of CMV lily isolates in intergenic region (IR) on RNA3, the genetic variation of IR from three different sources was investigated by a specific restriction endonuclease hydrolysis of amplified reverse transcription-polymerase chain reaction (RT-PCR) products using virus-specific primers, and was compared with IR sequences. The IR nucleotide sequences of CMV lily isolates were highly conserved, however, quasispecies was detected from all three sources in low level, containing sub-populations of RNA3. These subpopulations of RNA3 were inoculated onto zucchini squash by in vitro transcripts from corresponding full-length cDNA clones together with Eny RNA1 and 2 transcripts. The systemic symptom of zucchini plants infected by these quasispecies was chlorotic spotting, which was milder than severe mosaic and stunt symptom caused by Eny-CMV. The severity of symptom was correlated with RNA accumulation of viruses. These results suggest that the genome of CMV lily isolates consists of quasispecies populations.

• The Plant Pathology Journal
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• v.20 no.2
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• pp.131-134
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• 2004

A strain of Cucumber mosaic virus (CMV) was isolated from a weed, water chickweed (Stellaria aquatica), growing in the pepper field in Chunchon, Korea. This isolate, CMV-Sa, was differentiated from other CMVs based on biological properties and nucleotide sequence analysis of the coat protein (CP) gene. CMV-Sa showed different reactions to all the tested plants, except Capsicum annuum and Cucumis sativus, when compar-ed with those of CMV-Mf (subgroup I) and CMV-PaFM (subgroup II). Remarkably, in Nicotiana tabacum cvs. Samsun, Xanthi-nc and Ky-57, CMV-Sa induced local necrotic ring spots on the inoculated leaves and venal wave pattern and mosaic on the upper leaves. RNA analysis, serology, and RT-PCR of CP gene showed that CMV-Sa belonged to subgroup I of CMV. However, restriction enzyme analysis of the cDNA using AluI, HhaI, HincII, HindIII, HinfI and MspI showed that CMV-Sa was distinct from that of CMV-Mf. Based on comparison of the nucleotide of CP gene and deduced amino acid sequences between other CMV strains, CMV-Sa was closely related to CMV-Mf with 93.7% and 97.2 % identity, respectively.

• Research in Plant Disease
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• v.10 no.4
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• pp.241-247
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• 2004

Recently, we reported a satellite RNA (Paf-satRNA) which is encapsidated in a pepper isolate of Cucumber mosaic virus (CMV-Paf) regulated symptom attenuation of the helper virus. To characterize mild symptom domain of Paf-satRNA, a series of chimeric cDNAs of satRNAs were created by using full-length cDNA clones of Paf-satRNA and a Pep-satRNA, chlorosis-inducing satRNA in pepper plants, and analyzed for determinants of symptom attenuation. When compared the nucleotide sequences, the 3' and 5' terminal sequences of the two wild-type (wt) satRNAs contained relatively conserved sequences which are the typical to CMV satRNA. Ten bases insertions were found in PepY-satRNA, and two variable regions, 81st to 113th and 183rd to 265th from the 5'-end, were located in the middle parts of the satRNAs. To delineate the attenuated symptom-related domain for the Paf-satRNA, in vitro transcripts RNAs transcribed from the wt cDNAs and constructed chimeric cDNAs were combined with genomic RNAs, RNA1, RNA2 and RNA3, of CMV-Fny and inoculated onto Nicotiana benthamiana plants. These transcripts were fully infectious onto the N. benthamiana and infectivity was confirmed by the RT-PCR. Chimeric Paf(H/N)-satRNA and PepY(N/A)-satRNA as well as Paf-satRNA induced very mild mosaic or symptomless infection on N. benthamiana. By contrast, typical mosaic symptom and stunting of infected plants were induced when PepY-satRNA, PepY(H/N)-satRNA and Paf(N/A)-satRNA were infected to N. benthamiana. Paf-satRNA coinfected with CMV-Fny RNAs induced very mild to sympomless on pepper plants whereas PepY-satRNA-infected pepper expressed typical chlorosis mosaic symptom. Two kinds of chimeric mutants, Paf(H/N)-satRNA and PepY(N/A)-satRNA, induced mild mosaic or symptomless infection onto pepper plants, while PepY(H/N)-satRNA and Paf(N/A)-satRNA showed typical chlorosis and mosaic symptom with stunting. This results suggest that mild symptom-related domain for the Paf-satRNA was located on HpaI-NarI region.