• Korean journal of applied entomology
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• v.41 no.4
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• pp.293-298
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• 2002

Cadusafos and fosthiazate were applied at the rate of 1.8 g a.i./6$\m^2$ as pre-plant or pre-plant＋post-plant treatments on winter-grown oriental melon in a greenhouse soil infested with Meloidogyne arenaria. Nematicides reduced root-knot nematode population from 35 to 90% compared with control； fosthiazate was better than cadusafos (P ＝ 0.003) and fosthiazate pre-plant＋post-plant application reduced nematode population densities as much as 90%. Nematicides increased yield in an average of 23% (11-38%) in May, 39% (2-65%) in June, and 31% (12-46%) for the total (P ＝ 0.085). The residue in the fruit of oriental melon by post-plant treatment of fosthiazate exceeded maximum residue limit of 0.2ppm, while the Cadusafos residue was below the limit. It is concluded that fosthiazate cannot be used as a post-plant treatment in winer-grown oriental melon with overall consideration, i. e., danger of residue, value of melon, costs of nematicide, consumer demand on safer agricultural products, and effects of fallow.

• Korean journal of applied entomology
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• v.53 no.1
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• pp.85-91
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• 2014

In this study, we analyzed the phylogenetic characterization of root-knot nematodes (Meloidogyne spp.) in soils from fruits and vegetables greenhouses in Korea. Soil samples were collected from 12 greenhouse fields in which tomato, cucumber, watermelon, and Oriental melon were being cultivated. Meloidogyne spp. were detected in all the soil samples at an average number of $72{\pm}6$ nematodes/300 g of soil to $2,898{\pm}468$ nematodes/300 g of soil. Phylogenetic analysis using polymerase chain reaction-restriction fragment length polymorphism was attempted for the second-stage juveniles (J2) of Meloidogyne spp. collected from the greenhouse soils. Twelve Meloidogyne spp. from the greenhouse soils were classified into two groups by using HinfI digestion of mitochondrial DNA, resulting in 900, 410, 290, and 170 bp fragments (group A) and 900, 700, and 170 bp fragments (group B). Phylogenetic analysis based on mitochondrial DNA sequences (1,483-1,521 bp) showed that nine group A isolates were identified as Meloidogyne incognita (99.73-99.93%) and three group B isolates showed 99.54-99.73% similarity to Meloidogyne arenaria.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.211-216
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• 2006

Total of 36 sweet potato field soils were sampled to survey the occurrence of the root-knot nematodes (RKN). The 61% of sweet potato fields in Haenam, 40% in Iksan and 31% in Yeju were infested with RKN, respectively. Average population density of RKN was 324 juveniles per 300 g soil. The resistance screening of sweet potato cultivars against RKN was carried out by using clay pots in a greenhouse. Average temperature under ground 10 cm in pot was 21.5$^{\circ}C$ during the test. There was no difference in number of egg sacs among different inoculation methods, however the egg-inoculation method was easy for treatlnent and had stable far results. The multiplication ratio of Melioidogyne incognita differed from 6.3 times (Jeungmi) to 63.2 times (Yulmi) by sweet potato cultivas. There were no cultivars showing resistance to M. incognita, but Jinmi, Jeungmi and Borami had resistance to if arenaria, M. hapla and M. javanica.

• 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.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.242-248
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• 2013

In the Northeast of Brazil, expansion of guava crops has been impaired by Meloidogyne enterolobii that causes root galls, leaf fall and plant death. Considering the fact that arbuscular mycorrhizal Fungi (AMF) improve plant growth giving protection against damages by plant pathogens, this work was carried out to select AMF efficient to increase production of guava seedlings and their tolerance to M. enterolobii. Seedlings of guava were inoculated with 200 spores of Gigaspora albida, Glomus etunicatum or Acaulospora longula and 55 days later with 4,000 eggs of M. enterolobii. The interactions between the AMF and M. enterolobii were assessed by measuring leaf number, aerial dry biomass, $CO_2$ evolution and arbuscular and total mycorrhizal colonization. In general, plant growth was improved by the treatments with A. longula or with G. albida. The presence of the nematode decreased arbuscular colonization and increased general enzymatic activity. Higher dehydrogenase activity occurred with the A. longula treatment and $CO_2$ evolution was higher in the control with the nematode. More spores and higher production of glomalin-related soil proteins were observed in the treatment with G. albida. The numbers of galls, egg masses and eggs were reduced in the presence of A. longula. Inoculation with this fungus benefitted plant growth and decreased nematode reproduction.

• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.968-975
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• 2018

In the course of screening for microbes with nematicidal activity, we found that Enterobacter asburiae HK169 displayed promising nematicidal activity against the root-knot nematode Meloidogyne incognita, along with plant growth-promoting properties. Soil drenching of a culture of HK169 reduced gall formation by 66% while also increasing root and shoot weights by 251% and 160%, respectively, compared with an untreated control. The cell-free culture filtrate of the HK169 culture killed all juveniles of M. incognita within 48 h. In addition, the nematicidal activity of the culture filtrate was dramatically reduced by a protease inhibitor, suggesting that proteolytic enzymes contribute to the nematicidal activity of HK169. In order to obtain genomic information about the HK169 isolate related to its nematicidal and plant growth-promoting activities, we sequenced and analyzed the whole genome of the HK169 isolate, and the resulting information provided evidence that the HK169 isolate has nematicidal and plant growth-promoting activities. Taken together, these observations enable the future application of E. asburiae HK169 as a biocontrol agent for nematode control and promote our understanding of the beneficial interactions between E. asburiae HK169 and plants.

• Journal of Life Science
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• v.17 no.12
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• pp.1605-1609
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• 2007

The created microbial pesticide was used to examine its effects using the inside-pot test method. The selected microbial pesticide KBC3017 particle pesticide manufactured by using Monacrosporium thaumasium was used in the farm-house outdoor test to find the optimum consistency and its effects. The more amount used, the better effect it showed. However, the optimum consistency was 2% and the KBC3017 particle pesticide for which the diatomite and raw jade powder were used as an increaser, when used 2% level of the total amount of soil, showed 71% effect on nematode prevention. The root and the stem of crops were better compared to those without any pesticide used.

• Korean journal of applied entomology
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• v.39 no.2
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• pp.111-115
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• 2000

Fifty-two nematode predatory fungi were isolated from 37 soil samples collected from eight provinces in Korea. Isolated fungi were tested their predacity against Rhabditis sp. and Meloidogyne incognita in petri dish, and against M. incognita in greenhouse pot experiments. Fifty isolates had trapping organ of adhesive networks and two isolates had adhesive column or adhesive knob. In petri dish experiments, 5 1 isolates against Rhubditis sp. and 26 isolates against M. incognita showed over 91 % of predacity; in greenhouse experiments, however, only three isolates showed over 81% of predacity. These results imply that the results from the laboratory experiments are not consistent with those from the greenhouse experiments. Therefore, to select a promising biocontrol predatory fungi for plant-parasitic nematodes, the screening experiment should be conducted in conditions close to nature.

• Korean journal of applied entomology
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• v.43 no.1
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• pp.81-84
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• 2004

Plant-parasitic nematodes were surveyed at peach orchards in Gyeongbuk province for three years from 2000 to 2002. Species, density, frequency, Simpson's index, Shannon and Wiener index, and prominence value were analyzed. Plant-parasitic nematodes were isolated from 97 orchards out of 124 orchards. More important plant-parasitic nematode genera on peach were Tylenchorhynchus nudus, Criconemoides informis, Paratylenchus elachistus, Pratylenchus vulnus, and Helicotylenchus digonichus. Aphelenchus sp., Tylenchus sp., Heterodera sp., Scutellonema sp. were found, but were not important. Root-knot nematodes were not found even though they were serious in foreign countried.

• Korean Journal of Organic Agriculture
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• v.30 no.3
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• pp.423-439
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• 2022

The acute dermal and eye irritation tests of Photorhabdus temperata, a symbiotic bacterium of Heterorhabditis megidis Gwangju strain, were carried out in New Zealand white rabbit (Oryctolagus cuniculus), following the guidelines of OECD and Rural Development Administration (RDA) of Korea. In both tests, neither dermal nor eye responses were found from all the P. temperata treated rabbits and the results were classified as non-irritating. That is, erythema, eschar, edema, and any other dermal critical signs were not observed from all the experimental rabbits in the dermal irritation test. In the acute eye irritation test, no clinical signs of cornea, iritis, conjunctiva (redness, edema, lacrima, and chemosis) were observed from all the experimental rabbits. Individual ocular irritation, mean ocular irritation, and acute ocular irritation were calculated as 0.0. The results of dermal and eye irritation studies on P. temperata indicated that this bacterium could be a safe and effective alternative bionematicide against the most serious plant-parasitic root-knot nematodes in the genus Meloidogyne.