• Korean journal of applied entomology
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• v.49 no.1
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• pp.31-36
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• 2010

Mating disruption (MD) using synthetic sex pheromone lures has been used to control the Oriental fruit moth, Grapholita molesta (Busck), in apple orchards. In Korea, where several small apple orchards are clustered but independently managed, its efficacy has been suspected mainly due to immigration of any mated females from nearby untreated cultivating areas. This study developed an edge treatment technique to decrease any local MD-free zones in a specific MD-treated farm and to trap any immigrating mated females by installing MD lures and food traps around the apple farm with 10 meter intervals. The addition of the edge treatment to the MD significantly prevented leaf and fruit damages induced by G. molesta compared to MD only. Moreover, this study tried to optimize the MD control technique by determining frequency of MD application. It suggests two MD applications with the edge treatment at the end of March and at the early of July to be effective throughout the entire apple growing seasons.

• Korean journal of applied entomology
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• v.40 no.3
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• pp.219-226
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• 2001

To identity the composition and ratio of the sex pheromone in the asiatic leafroller, Archippus breviplicanus (Walsingham), which is a major pest on apple leaves, and to develop a monitoring system using this sex pheromone, abdominal tips of their virgin female during the calling period were extracted and analysed. The GC/GC-MS analysis revealed the following three compounds; (E)11-tetradecenyl acetate (E11-14: Ac), (Z)11-tetradecenyl acetate (Z11-14: Ac), and tetradecyl acetate(14: Ac) with the ratio of 56:22:22. Electroantennogram (EAG) assay was also conducted to examine biological activity of the components. The three components evoked significantly higher responses than hexane or air but there was no significant differences between the mixtures made by components. Field trapping experiments for determining the optimum blend, seasonal fluctuation and the optimum amount for male attracting were carried out over 4 years from 1997 to 2000. Although male moths were attracted to 8:2 and 7:3 between E11-14: Ac and Z11-14: Ac, their 7:3 blend was found to be the most effective. Archippus breviplicanus appears to occur three times a year in Korea. The optimum amount for monitoring was found to be 1mg per trap. 14: Ac, the third component, did not show synergistic effect on male moth attraction.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.39-49
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• 2017

The present study conducted a comparison on tree growth and productivity of high-density apple orchards by several orchard management systems: making scaffolds by heading-back and thinning out pruning (T-1), maintaining scaffolds upward and bearing shoots downward (T-2), managing branches slightly upward without heading-back (T-3), keeping leaders downward and shoots pending (T-4), maintaining leaders high and branches horizontal with severe pinching (T-5), making leaders with lower branches vigorous and upper shoots pending (T-6), and controlling very high planting density with bending branches (T-7). In conclusion, the orchards of (T-5) and (T-6) management systems showed a superior performance in controlling tree growth, productivity, and quality of fruits. Also, superior management efficiency was obtained in the orchards of (T-5) and (T-6).

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.266-271
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• 2010

Six insecticides, monocrotophos (24%, Lq), milbemectin (1%, Ec), tebufenpyrad (10%, Ec), propargite (30%, Wp), dicofol (42%, Ec), and fenpropathrin (5%, Ec) were studied for their $LC_{50}s$ to local two-spotted spider mite (TSSM) strains collected at apple orchards in Chungju, Kunwi and Sobo in Korea. Monocrotophos and fenpropathrin were not effective due to resistance development, but milbemectin, tebufenpyrad, dicofol and propargite were effective to TSSM. $LC_{50}$ values to TSSM strains showed the same distribution pattern among apple orchards. However, TSSMs from different apple orchard were clustered into different groups.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.289-294
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• 2009

Concerning about the negative impact of chemical pesticides on human health and the environment has been leading to dramatic increase of research in natural product-based pesticides. An antagonistic bacterium Streptomyces sp. S-1110 was isolated from apple farm soil. The culture filtrate of the strain showed growth inhibition effects to apple pathogenic fungi, Botryosphaeria dothidea, Colletotrichum gloeosporioides and Rhizoctonia solani. The unidentified antibiotic substances from the strain kept antagonistic activity either after heat treatment at $121^{\circ}C$ for 1 h or pH treatment at range of pH 3 - pH 12 for 24 h. The substances also prevented apple fruit from spoiling by inoculated two pathogenic molds, B. dothidea and C. gloeosporioides. These results suggested that the isolated strain would be useful as a biocontrol agent to control apple spoiling occurred from mold.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.5 no.8
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• pp.2-7
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• 1984

우리나라에 제일 먼저 도입된 과수는 사과이며 그후 경제적인 과수원이 조성된것은 1901년이고 국가적인 차원에서 시험연구사업이 시작된 것은 1906년부터이다. 과수병의 연구는 1910년 부터 배나무 붉은별무늬병을 비롯하여 몇가지 병에 대한 약제방제시험으로부터 시작되었다. 본격적인 농약으로서의 살균제는 석회보르도액이며 1945년 이전까지 주로 과수원에서만 사용되어 왔다.

• Current Research on Agriculture and Life Sciences
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• v.16
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• pp.84-95
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• 1998

Apple Marssonina blotch, caused by Diplocarpon mali, which has been increasing on apple trees and become one of the most serious diseases on apple trees in Korea since the begining of 1990's. In this study, ecology of Marssonina blotch including disease incidence and spore dispersals was surveyed from 1992 to 1995 in Kyungpook, and factors influencing the incidence of the disease were analyzed. Marssonina blotch began to occur on apple leaves in June and was observed commonly in most of apple orchards after August, and increased rapidly in September. The incidence of this disease was high at the year of low temperature and a lot of precipitation. The conidia discharge began to occur in May and continued to October, and the peak period of spore release was in August and usually more than 70% of total spore release of the year released from August to September. The incidence of the disease was high in the northern and mountain are as such as Yeongjoo, Chungsong, Andong, and relatively low in the southern areas such as Kunwi, Yongchon. Jonathan cultivar was the most susceptible to Marssonina blotch, and Jonagold, Sekaiichi was secondly susceptible and the next Fuji was more susceptible than Tsugaru. The incidence of the disease was relatively high in orchards which cultivation management of irrigation, drainage, air circulation, fertilization, and fungicide spraying were poor.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.275-278
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• 2018

An aquatic wasp, Agriotypus silvestris Konishi & Aoyagi, 1994 is newly recognized in South Korea. A diagnosis and photographs of the diagnostic characters for the species and an identification key to the South Korean Agriotypus species are provided herein.

• Korean journal of applied entomology
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• v.42 no.3
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• pp.257-262
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• 2003

Spider mites and their predacious mites were surveyed in an apple orchard where pesticides have not been applied for a long time, to understand the undisrupted predacious mite complex and their role in the controling spider mites. Spider mites occurring in the orchard were different to those in conventional orchards. A few Tetranychus urticae and Panonychus ulmi were observed, while T. kanzawai was abundant during growing season. Four species of phytoseiids, Amblyseius eharai, A. kokufuensis, A. womersleyi and Typhlodromus vulgaris, and one stigmaeid species of Agistemus terminalis were observed from leaf samples in the orchard. Among them, T. vulgaris occurred from early cool season with low T. kanzawai densities through to mid-and late-season. A. womersleyi was observed only during mid-season when T. kanzawai densities were high with hot weather. Amblyseius eharai and A. kokufuensis occured only in early season, but A. terminalis density increased from mid-season and lasted to late-season. The predacious mite complex regulated the density of T. kanzawai approximately under 8 mites per leaf. Tentatively concluding, T. vulgaris is an adaptable predator at lower prey density under cool weather condition, and A. womersleyi is effective predator at higher prey density under hot weather condition. Further, the biological control strategies of spider mites in Korean orchards were discussed based on the predacious mite complex.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.473-477
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• 2014

Halyomorpha halys (St${\aa}$l) (Hemiptera: Pentatomidae) is a typical polyphagous stink bug causing losses in several host plants including leguminous crops and fruits. Nutritional status of fruits such as apple and orange for the development of H. halys is not yet clear. We evaluated fruits of apple and orange with or without soybean-peanuts as food sources to investigate development, mortality and fecundity of the stink bug in a controlled condition. Those only fed on water could not develop into third instars. H. halys could not develop into fourth instar on apple only food. However, on an orange only food, 14% of H. halys emerged as adults. Those fed on orange only food had the longest development period (74.2 d). Total mortality of those fed on foods consisting of soybean-peanut ranged from 38 to 44%. In an average a female laid 169~190 eggs in a lifetime and those eggs had 81~83% hatchability. Results indicated that the apple fruit as a solo food source is an incomplete food for H. halys development while orange could support development of only few of the bugs.