• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2017.11a
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• pp.35-35
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• 2017

• Korean journal of applied entomology
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• v.24 no.3 s.64
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• pp.157-162
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• 1985

Leaf damage rate and actual damaged leaf area by the apple leaf miner (ALM), Phyllonorycter ringoniella(Matsumura), and its parasitism were investigated in 1982 and 1983 in apple orchards. Percent leaf damage was higher in the occasionally sprayed orchards than in the periodically sprayed orchards from May to August, but the trend was reversed after September. Seasonal changes of the leaf damage seemed to be different with the varieties of apple trees. A few species of Eulophidae and Holcothorax testaceipes R. of Encyrtidae were the predominant parasites of the ALM. Overall percent parasitism was highest in the 5th (overwintering) generation, and conspicuously decreased in the 3rd-4th generation (July-August) when insecticides were sprayed periodically. Actual damaged leaf area per mine of the ALM was apparently different with the generations; $0.67cm^2$ for the 1st, $0.8{\sim}0.9cm^2$ for the 2nd-4th on the first growth shoot, and $1.49cm^2$ for the overwintered generation on the second growth shoot. When ALM leaf damage rate was about $53{\sim}73%$, the decrease in the photosynthetic area to the damaged leaf was about $6{\sim}8%$.

• Journal of Practical Agriculture & Fisheries Research
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• v.15 no.1
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• pp.75-84
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• 2013

The management system and profitability were compared for the commercial orchards in the apple producing districts from April to October, 2011. The present study reasonably graded a large fruit as a fruit of heavier than 300g for 'Fuji' and 330g for 'Hongro' apples. As comparing cropping density and yield efficiency, 'Fuji' apples showed 3.28 fruits per TCA of crop density and 0.96 kg per TCA of yield efficiency and 'Hongro' demonstrated 4.04 fruits and 1.01 kg. With the application of the results above, the orchard management systems was classified into 3 classes as the orchard for large-size fruits, medium-size fruits, and combined size fruits. The increase of cropping density made the increase of fruit yield with medium-size fruits in unit area but brought about the decrease of large size fruits. The difference in fruit size failed to make significant differences in fruit characteristics. The orchard management system for producing medium size fruits performed decrease in input cost and improved the profitability in orchard management.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.443-447
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• 2012

Clearwing moths (Lepidoptera: Sesiidae) are economically important pests of fruit trees, such as apple, peach, and grape in Korea. Larvae feed on the phloem and cambium within tree branches of host plants. In this study, the seasonal fluctuation in male catches of four clearwing moths, Synanthedon haitangvora, S. bicingulata, Nokona regalis, and Glossosphecia romanovi, were monitored with the respective sex pheromone traps in Suwon for three years. In apple orchards, S. haitangvora males were captured from May to October, with two peaks in early June to middle June and late August to early September. Similarly, S. bicingulata males were trapped from May to October, with two peaks in late May and late August to middle September in peach orchards. In vineyards, N. regalis males were captured from late May to middle June with one peak in late May to early June, while G. romanovi males were trapped from early June to late July with one peak in late June to early July.

• The Korean Journal of Food And Nutrition
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• v.34 no.2
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• pp.174-180
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• 2021

The purpose of this study was to determine the optimum extraction method suitable for the availability of biological activities in unripe apples known to be rich in functional components. Unripe apples 'Hongro' picked on May 28th, 2019 were extracted by various extraction methods (hot water, ethanol, enzymatic pre-treatment, ultrasonic wave, and subcritical water) and their extracts were investigated yield, effective component contents, and antioxidant activities. Overall, the yields by the extraction solvent were higher in water than in organic solvent(ethanol) because water-soluble compounds were eluted from a polar solvent. Total phenol contents of the ultrasonic wave (ethanol) extracts were significantly higher in 6 times than hot water extract. Contents of flavonoid were highest in the ethanol extract at 29.14 mg QE/g. Contents of tannin and ursolic acid were also significantly higher in the ultrasonic wave (ethanol) extract. The DPPH radical and ABTS radical scavenging activities were the strongest in the ultrasonic wave (ethanol) extract. Correlation between effective components and antioxidant activities was high in the total phenol content with ABTS and the ursolic acid content with DPPH (p<0.01). The above results suggested that ultrasonic wave (ethanol) extract of unripe apples has the potential to act as a functional material.

• Microbiology and Biotechnology Letters
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• v.8 no.4
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• pp.221-227
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• 1980

The presence of L-malic acid in culture media contaniing glucose stimulated the growth rates of Leuconostoc oenos strains. The L-malic acid also stimulated the synthesis and activity of D-malate dehydrogenase (D-LDH) resulting in rapid production of D-lactate from glucose. The rapid utilization of glucose under the presence of L-malic acid may explain, in part, the stimulatory effect of the compound on the growth rate of leuconostocs.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.90-95
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• 1998

Soil residues of paraquat (1,1-dimethyl-4,4-dipyridinium dichloride) were determined in apple, pear, grape, and peach orchards for which 15 sites each were selected randomly from the corresponding large-scale production area throughout the country. Strong adsorption capacity measured using wheat bioassay (paraquat concentration required to reduce 50% root growth of wheat, SAC-WB) was also investigated on the orchard soils and the paraquat residue level was calculated against total SAC-WB values (SAC-WB value + paraquat residue). Average bound residue of paraquat on the 60 sites was 6.9 ppm, while paraquat residue in apple orchard reached 20.2 ppm which was the highest among the orchards and was almost double as compared with those in the other three orchards. Loosely bound residue of paraquat determined on the bound residue high top five soils occurred less than 0.5 ppm detection limit. Average SAC-WB value was 276.1 ppm and there were no any correlations between the SAC-WB value and clay content, organic matter content, and cation exchange capacity of the orchard soils. Paraquat residue level of the orchard soils against total SAC-WB recorded 2.43%.

• The Korea Beekeeping Bulletin
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• s.330
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• pp.61-61
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• 2008

본 협회에서는 농촌진흥청과 협조하여 도 기술원, 시.군 농업 기술센터에 행정 지시하여 과수농가 봄철 사과, 배 개화기에 맹독성농약사용을 금지하도록 협조 요청했다.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.05a
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• pp.198-198
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• 2002

• Korean journal of applied entomology
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• v.48 no.3
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• pp.319-325
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• 2009

Woolly apple aphid, Eriosoma lanigerum, overwintered as adult or nymph stage on rootstocks, and crown- and root sucker in the soil. In an un sprayed apple orchard, the number of E. lanigerum colony started to increase from mid-April, showed the 1st peak between late June and early July, thereafter decreased followed by the 2nd peak in late July, and then again peaked in late September as the size in the 1st peak. In this orchard, the number of E. lanigerum colonies per tree did not exceed 3.5 colonies during the peak occurrence period, and was maintained around 2 colonies throughout seasons. In all seasons, parasitism of Aphelinus mali on E. lanigerum was much lower on root colonies than on aerial colonies that located on shoots and tree trunks above the ground. The parasitism of E. lanigerum was high in most orchards examined, showing parasitism of > 70% in maximum in most cases. In the laboratory bioassay for the mortality effects of several insecticides on E. lanigerum, fenitrothion, dichlorphos, machine oil, methidathion, thiacloprid, and imidacloprid showed 97.8, 96.8, 95.4, 91.5, 26.7, and 7.8% morality, respectively. Also, the adult emergence rates from A. mali mummies were 51.2, 72.6, 14.2, 3.5, 72.2, and 85.4% in the treatment of the above insecticides, respectively. Insecticides belong to neonicotinoid, which are newly developed to control aphids, showed low mortality against E. lanigerum. Fenitrothion and dichlorphos were effective on E. lanigerum control and had a low toxic to A. mali. Consequently, the insecticides should be useful in integrated pest management system for E. lanigerum in apple orchards.