• Korean journal of applied entomology
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• v.55 no.1
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• pp.79-79
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• 2016

• Korean journal of applied entomology
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• v.46 no.2
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• pp.175-182
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• 2007

Two fruit moths of the oriental fruit moth, Grapholita molesta (Busck), and the peach fruit moth, Carposina sasakii (Matsumura), infest apples in Korea by internally feeding behavior. C. sasakii is a quarantine insect pest from some other countries importing Korean apples. G. molesta is not a quarantine insect pest, but can be incorrectly identified as C. sasakii especially when it is found inside apple fruits at its larval stages because it is not easy to identify the two species by morphological characters alone. This incomplete identification results in massive economical loss by fruits needlessly destroyed or turned away at border inspection stations of the importing nations. This difficulty can be overcome by molecular DNA markers. Several polymorphic regions of mitochondrial DNA of both species were sequenced and used for developing specific striction sites and polymerase chain reaction (PCR) primers. Based on these sequences, three diagnostic PCR-restriction fragment length polymorphism (RFLP) sites were detected and validated for their practical uses. Also, species-specific PCR primers were devised to develop diagnostic PCR method for identifying the internal feeders.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.6
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• pp.383-387
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• 2004

Effects of oyster shell powder as a liming material were investigated in an apple orchard. Soil texture of the apple orchard was silty clay loam (Upyeong series with 7% of slope) and topsoil pH was 5.6. Treatments of 1,590 kg oyster shell powder $ha^{-1}$ and calcium-magnesium carbonate as much as oyster shell powder were included in the experiment. With treatments of oyster shell powder and calcium-magnesium carbonate, the length, number and diameter of new branches and the diameter of main, secondary and side branches increased in comparison with control. With oyster shell powder application, soil pH increased from 5.6 to 6.8 at the harvest. In addition, it increased exchangeable Ca from 2.6 to $4.2cmol_c\;kg^{-1}$. But it didn't make any difference in chlorophyll, sugar and malic acid contents. The apple weight per fruit of oyster shell powder application was 9 g more than that of control. Apple yield was highest ($37,000kg\;ha^{-1}$) in the oyster shell powder treatment, and the yield increase was significantly different at 5% level LSD. We concluded that the oyster shell powder can be an alternative of lime and effective to restore soil nutrient balance in apple orchard soil.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.271-279
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• 2016

To evaluate exposure characteristics of the insecticide imidacloprid to apple orchard workers during treatment on orchard fields and evaluate its potential risk using a whole body dosimetry (WBD) method, 1,000-time diluted acephate+imidacloprid 25(20+5)% solutions were sprayed on 10 apple orchard fields in Cheongju with a speed sprayer at a rate of 3,000 L/ha/person, after put on clothes such as inner/outer clothes, personal air pump with a IOM sampler, nitrile glove and mask. Exposure test included mixing, loading and application steps. The test pesticide imidacloprid residues in the collected samples were analyzed with a HPLC-DAD. Recoveries ranged from 81.5 to 108.6% for analytical method validation and from 73.8 to 86.7% for field recovery. Total exposed amounts to mixer/loader and applicator were found to be 0.0014-0.0279% of total applied active ingredient of imidacloprid. Glove exposure of both mixer/loader and applicator was higher than the other parts. Margins of safety of mixer/loader and applicator were calculated to be 97-355 and 46-196, respectively, indicating that exposure risk of imidacloprid to apple orchard workers by spraying with a speed sprayer was very low.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.4
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• pp.572-577
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• 2002

We investigated the optimal condition for production of bacterial cellulose with Gluconacetobacter persimmonus KJ145. For bacterial cellulose production, optimal medium composition and culture conditions were conducted to determine. Apple juice (10$^{\circ}$Brix) medium was suitable than Hestrin & Schramm medium which is generally used for the bacterial cellulose production. When 1% pyruvate as carbon source was added to apple juice, bacterial cellulose production rose to high level. The effect of various nitrogen sources was investigated: CSL was found to be essential to high cellulose yields and the optimal CSL concentration was 10%. Optimal temperature and culture time for the bacterial cellulose production was 35$^{\circ}C$ and 16 days, respectively At the optimal condition Gluconacetobacter persimmonus KJ145 produced 8.96g/L of bacterial cellulose (dry weight), which was much higher than reported values.

• Korean journal of applied entomology
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• v.57 no.3
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• pp.209-220
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• 2018

Mating disruption (MD) has been widely used to effectively control Grapholita molesta in apple orchards. A simultaneous mating disruption (SMD) techniques have been developed to control both G. molesta and G. dimorpha. This study was performed to determine the practical parameters to apply the SMD technique to field conditions. To determine the application amount of SMD lures, a dispenser containing 10 mg pheromone was placed at different numbers of trees in an orchard. Application at every other tree (= one dispenser per two trees) was relatively safe to expect effective MD efficiency in both wax and polyethylene (PE) formulations. One time application at the end of March was enough to maintain a year round MD efficacy against both species. A fence treatment using food trap was applied to prevent any immigratory mated females from nearby untreated regions. To enhance the food trap by adding host-derived secondary compounds, terpinyl acetate (TA) was screened to be effective to attract females of Grapholita molesta among six compounds contained in apple fruit extracts. Among different TA concentrations, 0.05% TA treatment was the most effective to attract the adults. A mixture of TA and sugar was effective to attract and kill females and called FAKT (female attract-to-kill techniques). FAKT was treated at approximately 6 m interval at the edge of the apple orchards. The females trapped by the FAKT included mated females possessing vitellogenic oocytes. SMD supplemented with FAKT maintained the high MD efficacy and significantly suppressed leaf damage induced by the two insect pests compared to control or single SMD treatment.

• Research in Plant Disease
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• v.9 no.4
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• pp.229-236
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• 2003

The 1080 epiphytic bacteria obtained from 370 samples of pome and stone fruits including apple, pear, peach, grape, apricot and Chinese quince were screened for antagonistic activity against postharvest pathogens, Penicillium expansum, Alternaria alternata and Botrytis cinerea. Among tested antagonistic bacteria, eight bacterial isolates inhibited mycelial growth of the postharvest pathogens and were identified as Bacillus amyloliquefaciens (three strains), B. megaterium, B. subtilis var. gladioli, B. licheniformis, B. pumilus and Serratia marcescens based on biochemical characteristics and utility of carbon and nitrogen compounds (Biolog system). Eight carbohydrates were evaluated for their effect on mycelial growth and germination of the postharvest pathogen, P. expansum to select nutrients for enhancing bio-control efficacy. The growth of four selected antagonists, B. amyloliquefaciens P43-2, B. amyloliquefaciens A71-2, B. licheniformis P94-1, and S. marcescens P76-9 were also tested. As a result, 1% glucose (w/v) strongly stimulated growth of the antagonists, suppressed mycelial growth of the postharvest pathogen, and had a little comparatively stimulatory effect on germination of the the postharvest pathogen. It was confirmed that the addition of 1% glucose (w/v) greatly enhanced biocontrol effect of B. amyloliquefaciens P43-2, B. licheniformis P94-1, and S. marcescens P76-9. Application of B. amyloliquefaciens P43-2, B. licheniformis P94-1, and S. marcescens P76-9 with the addition of 1% glucose (w/v) increased the control efficacy up to 48%, 46%, 14% compared with those of the antagonists without glucose, respectively. When the antagonists were applied to control postharvest disease caused by P. expansum in apple wounds, the population of B. amyloliquefaciens P43-2 and B. licheniformis P94-1 increased until 4 days after inoculation (DAI) of the antagonists and then decreased from 10 DAI. Meanwhile the population of S. marcescens P76-9 decreased at early stage (4 DAI), but increased from 7 DAI, and finally maintained constantly until 10 DAI in apple wounds.

• Korean journal of applied entomology
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• v.50 no.1
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• pp.29-37
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• 2011

A remote sensing pheromone trap called IT pheromone trap (Korean patent: 10-0982563) was applied to monitor overwintering population changes of the oriental fruit moth, Grapholita molesta, for three successive years in apple orchards. Males of the overwintering populations were attracted during April and May. However, the occurrence peak was delayed and extended to early June in 2010, at which the average spring temperature was significantly lower than the previous years. These overwintering populations could be monitored by the remote-sensing pheromone trap. When the remote-sensing pheromone traps were deployed to apple orchards of different provinces in Korea in 2010, the maximal overwintering populations of G. molesta were monitored at May in all areas. However, the population sizes monitored were significantly different among different localities. This study suggests a practical application of IT pheromone trap to monitor G. molesta in field conditions.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.328-333
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• 1995

Susceptibilies of tow-spotted spider mite (Tetranychus urticae Koch) collected at 6 locations were assessed to 15 acaricides. The response to acaricides were almost similar in female adults and eggs. There were considerable difference in susceptibility depending on the acaricide treated and the region from which the population was collected. The population showing resistance ratio of more than 20 with respect to certain acaricide was regarded as a resistant population to the acaricide. The resistant populations in terms of female adult were as follows: Suwon population to azocyclotin, cyhexatin, and fenbutatin-oxide; Taejon population to dicofol and fenbutatin-oxide; Chongju population to dicofoll Chinju populatin to cyhexatin, dicofol, and fenbutatin-oxide. The resistant populations in terms of egg were as follows; Suwon population to bifenthrin, clofentezine, hexythiazox, and tetradifon; Kunwi, Chongju, and Kwangju populations to bifenthrin; Taejon population to amitraz and bifenthrin; Taejon populatin to amitraz and bifenthrin; Chinju population to amitraz, bifenthrin, clofentezine, dicofol, and tetradifon. However, the female adults and eggs of all field populations were susceptible to abamectin, chlorfenson, and fenpyroximate. This tendency was also reported previously in the susceptible strain from laboratory.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.232-237
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• 1996

Toxicity of 5 acaricides, 4 insecticides. and 6 fungicides to the twospotted spider mite, Tetranychus urticae Koch, and its predator Amblyseius womersleyi Schicha was assessed in a laboratory using a leaf disk bioassay. Dicofol was equally very toxic to aduly females of T. urticae and A. womersleyi, and caused 46% and 40% mortality of eggs of those two species, respectively. Adult females of A. womersleyi dipped in Abamectin solution showed low mortality(16.6%), while all T. urticae females died within 24 hours after dipping. Three ovicidal acaricides (Tetradifon, Clofentezine, and Hexythiazox) showed no mortality of predator eggs, but more than 90% mortality of T. urticae eggs. Four insecticides (Teflubenzuron, Triflumuron, Diflubenzuron, and Imidacloprid) and three fungicides (Propineb, Fenarimol, and Polyoxin-B captan) were non toxic to the A. womersleyi adult females. The other fungicides (Chlorothalonil, Nuarimol.Mancozeb, and Folpet) were a little toxic to adult females of the predator, showing$\leq$23.3% mortality, It may be suggested from these results that 4 insecticides, 4 acaricides, and 6 fungicides described could be incorporated into the integrated pest management system with A. womersleyi in apple orchard.