• Journal of Food Hygiene and Safety
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• v.30 no.2
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• pp.178-188
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• 2015

Microbial quality of baked egg products was evaluated by counting the levels of sanitary indicative bacteria (aerobic plate counts, coliforms, and E. coli), L. monocytogenes and Salmonella spp. at the critical control points (CCPs) of manufacturing process. In addition, the survival and growth of foodborne pathogens in various egg products (cheese, tuna, tteokgalbi, pizza omelets, baked egg, and steamed egg) were investigated at 4, 10, and $15^{\circ}C$. The contamination level of aerobic plate counts decreased from 4.67 log CFU/g at CCP 1 to 0.56 log CFU/g at CCP 3 in baked egg products. No coliforms and E. coli were detected at all CCPs. Although L. innocua and Salmonella spp. were identified at CCP 1, no L. monocytogenes and Salmonella spp. were detected in the final products. The contamination levels of aerobic plate counts and coliforms in egg strips and number of aerobic plate counts in Tteokgalbi omelet are higher than the microbiological standard of processed egg products. At $10^{\circ}C$, the growth of all pathogens was not prevented in omelet and baked egg, but the populations of S. Typhimurium and E. coli were reduced in steamed egg at $10^{\circ}C$, regardless of the presence of other pathogens. The growth of L. monocytogenes was faster than that of S. Typhimurium and E. coli in omelet. More rapid growth of S. Enteritidis than S. Typhimurium was observed in egg products, indicating the greater risk of S. Enteritidis than S. Typhimurium in egg products.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.391-398
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• 2014

This study investigated inhibitory doses of electron beam and X-ray irradiation by comparing their effects on the development and reproduction of four insect pests (Myzus persicae, Tetranychus urticae, Liriomyza trifolii, and Frankliniella intonsa). When M. persicae nymphs were irradiated with 100 Gy of electron beam and 30 Gy of X-ray beam, offspring production by adults that developed from the treated nymphs was completely inhibited. When M. persicae adults were irradiated with 200 Gy of electron beam and 50 Gy of X-ray beam, emergence of the $F_1$ generation was inhibited. However, these two ionizing radiations did not affect adult longevity. When T. urticae eggs were irradiated with 150 Gy of electron beam and 50 Gy of X-ray beam, egg hatching was completely inhibited. When L. trifolii pupae were irradiated, the emergence rate decreased with increasing doses of X-ray irradiation. After F. intonsa adults were irradiated with 250 Gy of electron beam and 200 Gy of X-ray beam, egg hatching of the $F_1$ generation was completely suppressed.

• The Plant Pathology Journal
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• v.40 no.3
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• pp.261-271
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• 2024

Sulfur is one of the inorganic elements used by plants to develop and produce phytoalexin to resist certain diseases. This study reported a method for preparing a material for plant disease resistance. Sulfur nanoparticles (SNPs) stabilized in the chitosan-Cu²⁺ (CS-Cu²⁺) complex were synthesized by hydrolysis of Na₂S₂O₃ in an acidic medium. The obtained SNPs/CS-Cu²⁺ complex consisting of 0.32% S, 4% CS, and 0.7% Cu (w/v), contained SNPs with an average size of ~28 nm as measured by transmission electron microscopy images. The X-ray diffraction pattern of the SNPs/CS-Cu²⁺ complex showed that SNPs had orthorhombic crystal structures. Interaction between SNPs and the CS-Cu²⁺ complex was also investigated by ultraviolet-visible. Results in vitro nematicidal effect of materials against Meloidogyne incognita showed that SNPs/CS-Cu²⁺ complex was more effective in killing second-stage juveniles (J2) nematodes and inhibiting egg hatching than that of CS and CS-Cu²⁺ complex. The values of LC₅₀ in killing J2 nematodes and EC₅₀ in inhibiting egg hatching of SNPs/CS-Cu²⁺ complex were 75 and 51 mg/l, respectively. These values were lower than those of CS and the CS-Cu²⁺ complex. The test results on the nematicidal effect against M. incognita on coffee pots showed that the SNPs/CS-Cu²⁺ complex was 100% effective at a concentration of 150 mg/l. Therefore, the SNPs/CS-Cu²⁺ complex could be considered as a biochemical material with potential for agricultural applications to control root-knot nematodes.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.596-606
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• 2021

Soil-borne diseases are the major problems in mono cropping. A mixture (designated LTM-m) composed of agricultural wastes and a beneficial microorganism Streptomyces saraceticus SS31 was used as soil amendments to evaluate its efficacy for managing Rhizoctonia solani and root knot nematode (Meloidogyne incognita). In vitro antagonistic assays revealed that SS31 spore suspensions and culture broths effectively suppressed the growth of R. solani, reduced nematode egg hatching, and increased juvenile mortality. Assays using two Petri dishes revealed that LTM-m produced volatile compounds to inhibit the growth of R. solani and cause mortality to the root knot nematode eggs and juveniles. Pot and greenhouse tests showed that application of 0.08% LTM-m could achieve a great reduction of both diseases and significantly increase plant fresh weight. Greenhouse trials revealed that application of LTM-m could change soil properties, including soil pH value, electric conductivity, and soil organic matter. Our results indicate that application of LTM-m bio-organic amendments could effectively manage soil-borne pathogens.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.324-329
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• 1995

Severe Fusarium wilt of tomato was observed in greenhouses in Sedo, chungnam and Sandae, Kyeongbuk from march to May 1993. Among the 20 isolates of Fusarium oxysporum isolated from wilted tomato plants and their rhisoplane or rhizosphere, 18 isolates were pathogenic to tomato. All of the pathogenic isolates were identified as F. oxysporum f. sp. lycopersici; they were pathogenic only to tomato and not pathogenic to red pepper, potato and egg-plant. The isolates of F. oxysporum f. sp. lycopersici used in this study could be divided into 2 races according to their pathogenicity to eight differential varieties of tomato. Of 10 isolates tested, 6 were classified as race 1, while 4, as race 2.

• Journal of Plant Biology
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• v.30 no.1
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• pp.59-67
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• 1987

To verify allelopathic effect of tomato plants a number of labovatory experiments, seed germination and seedling growth with aqueous extracts and leachates form the tomato plants, have performed. Germination percentage of the tested species was decreased by treatment with leaf, stem and root extracts as extracting time elapses. The leaf extract more inhibits the germination of the seeds than both stem and root extracts. Leachate collected from the tomato plants decreases as much as 50% of the growths in elongation as well as dry weight of seedlings of lettuce and egg plant. It is observed that with a paired-plants grown in U tube pot the tomato roots have excreted allelochemicals to inhibit the growth of the tested species and volatile substances from the tomato plants have suppressed to dry weights of lettuce, to elongation and dry weights of grapevine planted near the tomato plants.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.162-168
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• 2012

An nematophagous fungi Arthrobotrys thaumasia Nema-1 and Bacillus subtilis C-9, which degrade the collagen and gelatin, were isolated from horticulture plantation soil in Kyungpook Sungju-gun Seonnam-myun and Chungnam Gongju-gun Woosung-myun to develop biological nematode pesticide. When $5,000mg\;kg^{-1}$ of A. thaumasia Nema-1 nematicide powder ($7.0{\times}10^3cfu\;g^{-1}$) was treated to pot including Meloidogyne incognita, the number of nematode's egg mass, which is a index of nematicidal activity, decreased to 35% compared to control. While the number of nematode's egg mass decreased to 67% by treating the nematicide powder mixture of $5,000mg\;kg^{-1}$ Nema-1 and B. subtilis C-9 ($8.5{\times}10^5cfu\;g^{-1}$). Furthermore the number of nematode's egg mass of the mixture containing cinnamon extract $10mg\;kg^{-1}$, each $5,000mg\;kg^{-1}$ of Nema-1 and C-9 nematicide powder was decreased to 84%, comparing to the result showed the number of nematode's egg mass decreased to 24%, by the treatment of chemical nemato pesticide Fosthiazate $24mg\;kg^{-1}$. These results suggested the mixture of microorganisms and plant extract was more effective biological nematicide than the case of only microorganism or plant extract for nematode control.

• Research in Plant Disease
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• v.16 no.1
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• pp.74-80
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• 2010

Emulsification characters were investigated for COY (Cooking oil and Egg Yolk Mixture) and control efficacies of COY was enhanced by supplemented Sulfur wp. against paprika powdery mildews. Amount of water added to one egg yolk and 100 ml olive oil affected tbe homogenization of mixtures to emulsion profoundly; those premixes with 5~10 ml water were too concentrated to be homogenized, hence not dispersible in water; those with 15~20 ml water were homogenized, but tended to flocculation and not readily dispersible in water, suggesting the instability of emulsion; and those with 50 or 100 ml water were homogenized well and was readily dispersible in water to stable emulsion over long period of time. It was further confirmed that those fruits sprayed with not-fully emulsified COY revealed the oily membranes or blotches on their surfaces, whereas the ones with fully emulsified COY revealed normal clean surfaces. Treatment of COY either alone or in supplementation with Sulfur wettable powder (sulfur wp) were also effective in suppressing the recurrence of powdery mildew signs, wbich had disappeared in three days of foliar application. Still, the COYs supplemented with sulfur wp (COY+sulfur wp) at 1,000x or 5,000x were significantly effective in suppression against the symptomlsign recurrence over COY or sulfur wp alone.

• Research in Plant Disease
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• v.27 no.2
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• pp.61-65
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• 2021

Root-knot disease caused by Meloidogyne incognita is major soil pathogen and cause severe economic damages to vegetable crops. In this study, we selected rhizobacteria for biocontrol of the root-knot nematode, M. incognita, and identified; performed bioassay of the bacterial extracts in cucumber seedlings. The crude extracts of strains CT16 and JC05 out of 180 strains inhibited egg hatching and increased juvenile mortality in vitro assay; based on 16S rRNA sequences analysis, the two strains were identified as Bacillus sp. CT16, and Neobacillus sp. JC05. After extracting the bacterial supernatants by using various organic solvents, n-butanol and n-hexane extracts of strain CT16 and n-butanol extract of strain JC05 showed inhibitory activity of egg hatching depending on concentrations. Subsequently, n-butanol extracts of two strains significantly suppressed formation of egg masses in cucumber seedling. Therefore, these results indicated that strains CT16 and JC05 could be used as potential biocontrol agents against M. incognita.

• Korean Journal of Veterinary Research
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• v.51 no.3
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• pp.193-201
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• 2011

An attenuated vaccine strain AVR1/08 of Korean respiratory type of infectious bronchitis virus (IBV) was developed by 89th passages of IBV D85/06 strain in chicken eggs. The AVR1/08 strain had higher virus titer at least 20 times ($10^{1.3}$) than the parent virus D85/06 by egg inoculation method. The AVR1/08 strain had a single point mutation (S to Y) at position 56 of spike protein of IBV compared to parent virus IBV D85/06 strain. The mutation was observed consistently at viruses after 47th passage in chicken eggs. The AVR1/08 strain showed no virulence even after 6 passages in chickens and all chickens inoculated induced anti-IBV antibody 14 days after vaccination. The AVR1/08 strain had broad protective efficacy against QX type Korean nephropathogenic virus (Q43/06 strain), KM91 type Korean nephropathogenic virus (KM91 strain) and Korean respiratory virus (D85/06 strain). In contrast, Massachusetts (Mass) type attenuated vaccine strain H120 showed protection of 37.5 to 50% against these three viruses. Our results indicate that the AVR1/08 strain has potential as an attenuated vaccine effective in controlling IBVs circulating in Korea.