• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.1
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• pp.597-604
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• 2016

The aim of this study was to prevent the decrease in crop output by disease and insect pests and excessive spraying of agricultural pesticides by application uniformity. A 3m height and 15km/h speed is difficult to maintain with an unmanned helicopter for aerial application, which has been affected by the controlling habits and methods or environmental factors, such as changes in the wind. Therefore, in this study, an aerial application system was design to be attached to an unmanned helicopter, which can allow a controlled application width and spray rate automatically and verified experimentally using Rmax of MS-AVIATION. The size of agricultural land was 50 m2 and nine water sensitive cards were arranged at 1.25m intervals in 5 rows with each row having a 10m interval from the position of 5m. The unmanned helicopter was flying at speeds ranging from 7.2km/h to 17.6km/h and heights ranging from 2.32m to 3.47m. The proposed aerial application system allowed application uniformity by making a valid spraying area of 7.5 m2 with 46423 particles distributed on average.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.411-421
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• 2005

This study was carried out to establish rational methodologies for the use of pesticide formulations to be sprayed after water-dilution. Hardness and electric conductivity of six major river water and ground water sampled from 52 sites in major rice-growing areas across the country ranged from 5 to 324 ppm(av. 90 ppm) and from 0.038 to 1.078 dS/m(av. 0.265 dS/m), respectively, which are acceptable for diluent water of pesticides. The pH changes in pesticide spray solutions with time after preparation mainly depended on the pH of the water used for pesticide dilution. The surface tensions of pesticide spray solutions reduced slightly with time after preparation, irrespective of kinds of pesticide formulations. Suspensibility of WPs became worse with an increase in the hardness and salt concentrations of diluent water, even though the degree was negligible. Emulsion stability of ECs became worse with an increase in hardness and salt concentrations of diluent water. Degradation rates of the active ingredients of pesticide spray solutions 3 days after preparation were less than 5%, regardless of mixing or non-mixing of two or more pesticides. Consequently, the spray solutions of most pesticides were usable until two to three days after preparation unless physical properties deteriorated. The tank-mixing order of EC and WP formulations did not make any differences in all the physical properties of pesticide spray solutions. However, the proper order for the tank-mixing of compatible pesticides was WP, WG, SC, EC, and SL, because the order is easy to prepare the pesticide spray solutions. The efficacy of pesticide spray solutions on the respective target pathogens and insect pests of rice plants three days after preparation was recorded over 95% of that of 0 day, which was almost the same as that of the solutions applied punctually after preparation.

• The Korean Journal of Pesticide Science
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• v.11 no.3
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• pp.210-215
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• 2007

This study aims to investigate if the properly use of pesticide in Ginseng farmland at Gangwon-do, Korea. Questionnaire included 36 questions such as control method for plant diseases, pests and weeds and pattern of pesticide use was answered by 271 Ginseng farmers lived in 4 cities and 8 counties at Gangwon-do. Ginseng farmers have noxious plant diseases, insects and weeds such as leaf spot, anthracnose, snail, stem-mining fly, horseweed and hairy crabgrass. To control of these, 35% of farmers relied on various type of pesticides and 31.5% of farmers used pesticides mingling with natural enemy, microorganism and organic materials. Farmers selected the pesticide based on the their own experiences or by recommendation of market dealers and neighbors, resulting in the use of inappropriate pesticides in the Ginseng farmland(78.8 % ). They followed standard dosage of the pesticide from Handbook of Pesticide Application(96.3%). They, however, used the same pesticides from 2 to 5 years(44.1 %). This consecutive use of pesticide could be induced resistance. This survey resulted that study for pesticide resistance and systematic educational program for proper use and selection of pesticide to Gingseng farmers should be conducted in farmland at Gangwon-do, Korea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.68-78
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• 2020

Crop models have been used to predict vegetable crop yield, which would have a considerable economic impact on consumers as well as producers. A small number of models have been developed to estimate growth and yield of vegetables due to limited availability of growth observation data in high-quality. In this study, we aimed to analyze the protocols designed for collection of the observation data for major vegetable crops including cabbage, radish, garlic, onion and pepper. We also designed the protocols suitable for development and verification of a vegetable crop growth model. In particular, different measures were proposed to improve the existing protocol used by Statistics Korea (KOSTAT) and Rural Development Administration (RDA), which would enhance reliability of parameter estimation for the crop model. It would be advantageous to select sampling sites in areas where reliable weather observation data can be obtained because crop models quantify the response of crop growth to given weather conditions. It is recommended to choose multiple sampling sites where climate conditions would differ. It is crucial to collect time series data for comparison between observed and simulated crop growth and yield. A crop model can be developed to predict actual yield rather than attainable yield using data for crop damage caused by diseases and pests as well as weather anomalies. A bigdata platform where the observation data are to be shared would facilitate the development of crop models for vegetable crops.

• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.2
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• pp.47-56
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• 2020

Decline of pine forests happens in Korea due to various disturbances such as insect pests, forest fires and extreme climate, which may further continue with ongoing climate change. For conserving and reestablishing pine forests, understanding climate-induced future shifts of pine tree distribution is a critical concern. This study predicts future geographical distribution of Pinus densiflora, using Maximum Entropy Model (MaxEnt). Input data of the model are locations of pine tree stands and their environmental variables such as climate were prepared for the model inputs. Alternative future projections for P. densiflora distribution were conducted with RCP 4.5 and RCP 8.5 climate change scenarios. As results, the future distribution of P. densiflora steadily decreased under both scenarios. In the case of RCP 8.5, the areal reductions amounted to 11.1% and 18.7% in 2050s and 2070s, respectively. In 2070s, P. densiflora mainly remained in Kangwon and Gyeongsang Provinces. Changes in temperature seasonality and warming winter temperature contributed primarily for the decline of P. densiflora., in which altitude also exerted a critical role in determining its future distribution geographic vulnerability. The results of this study highlighted the temporal and spatial contexts of P. densiflora decline in Korea that provides useful ecological information for developing sound management practices of pine forests.

• Korean journal of applied entomology
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• v.62 no.1
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• pp.43-48
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• 2023

The efficacy of spinetoram sprayed from an unmanned helicopter to control two insect vectors of pine wood nematodes, Monochamus alternatus and M. saltuarius was assessed. By using a ULV (Ultra Low Volume) sprayer, the mortality rates of phenthoate, bifenthrin, etofenprox, and diflubenzuron, which are registered for use against coleopteran insects, indoxacarb and spinetoram, which are registered for use against lepidopteran insects, were evaluated for efficacy as aerial spraying agents. The ULV test, using 33- and 55-fold dilutions of phenthoate, bifenthrin, indoxacarb, and spinetoram demonstrated a 100% insect mortality rate upon contact and feeding mortality on the third day after treatment, while etofenprox and diflubenzuron exhibited a slightly lower mortality rate than the remaining compounds. Consequently, spinetoram was selected as a candidate pesticide for aerial spraying and its efficacy to control the insect vectors was assessed. The x 33 dilution of spinetoram resulted in a 98.6-100% control efficacy against two insect vectors. However, risk assessment for bees following aerial spraying will be necessary before applying the pesticide to control insect vectors.

• Journal of Mushroom
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• v.21 no.4
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• pp.266-269
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• 2023

This study aimed to address the increasing demand for technologies preventing mushroom fly damage. By monitoring the annual occurrence patterns of pests over several years and accumulating data, we conducted an analysis to evaluate the efficacy of preventive measures applied before the surge in mushroom fly infestation, typically observed in May. For preemptive control, physical measures involved installing air curtains at cultivation facility entrances and placing sticky traps and insect traps around entry points to block external entry and reduce internal insect density. Additionally, we applied an organic agricultural material, Dalmatian chrysanthemum extract, weekly alongside chemical control measures. To assess the reduction in mushroom fly populations, yellow sticky traps (15×25 cm) were placed at three locations within the mushroom cultivation facility, and the occurrence patterns before and after implementing preventive measures were compared. Compared to conventional practices, the application of preventive techniques resulted in a significant reduction, with a 60% decrease from 15 levels of mushroom flies/m² to 6 levels of mushroom flies/m² in May and a 40% decrease from 10 levels of mushroom flies/m² to 6 levels of mushroom flies/m² in June. While achieving over 50% efficacy during the peak mushroom fly season with preventive measures, we identified complementary actions such as blocking external sources (gaps in cultivation facility doors) and maintaining cleanliness around cultivation facilities (proper disposal of spent substrate) for further improvement. Comprehensive analysis and safety studies, including correlation analysis with contaminants and pathogens, are recommended to ensure the widespread adoption of mushroom fly preventive techniques for safe and stable mushroom production in the agricultural sector.

• Journal of Mushroom
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• v.7 no.3
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• pp.115-121
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• 2009

Recently sawdust cultivation of Shiitake mushroom (Lentinula edodes ) is getting increased because log cultivation is getting difficult to get oak logs. It is important to make mycelia browning on the substrate surface in sawdust cultivation. This browned surface plays an important role like as artificial bark of the oak log, which protects the other pests and suppresses water evaporation in the substrate. The period for mycelia browning is so long that the sawdust cultivation of Shiitake mushroom can not spread well into the mushroom farms. In this article we would like to discuss about the effect of environmental condition to the mycelial browning during sawdust bag cultivation for the To reduce the period required for browning of substrates, sawdust substrates was illuminated light with difference intensity. One hundred Lux light illumination was needed for producing normal yield of fruit body but fruit body yield was low and abnormally shaped fruit body was produced when cultured under the dark condition of incubation. Illumination over 200lux is necessary for the successful browning of substrates during incubation. Optimum incubation temperature for browning of substrates and fruiting was $25^{\circ}C$. The treatment of cotton plug with different size to identify the effect of aeration on the browning of substrates and fruiting showed rapid mycelial growth and reduced the periods for browning as the size of cotton plug was bigger. However, yield of fruit body was the highest at 16mm diameter cotton plug as compared to 20mm of that. $CO_2$ content in vessel of substrates was low as the size of cotton plug was bigger during incubation. $CO_2$ content during incubation of substrate was highest in periods between 8 week and 14 week after inoculation of shiitake when substrate was changed color into brown. $C_2H_4$ content in vessel with substrates was highest at 8mm diameter cotton plug and it was increased by order of 12, 16, 20, 0, 4 mm diameter cotton plug during substrate incubation. Sawdust substrate was soaked in cold water for different time to identify soaking effect of sawdust substrate on fruit body yield and activities of enzymes in these substrates were investigated. The fruit body yield was increased up to 40% by soaking substrates in comparison with unsoaked substrates. The soaked substrates showed 165, 175g/1,000ml at treatment of 4 and 15 hours, respectively. Cellulose activities in soaked substrates were not changed with soaking time, but activities of laccase, lignin degradation enzyme, were drastically increased up to 4 times in comparison with unsoaked substrates.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.315-323
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• 2023

The brassica leaf beetle, Phaedon brassicae Baly (Coleoptera: Chrysomelidae), is one of the important pests infesting cruciferous vegetables. In order to understand the biological characteristics of the insect, we investigated the effects of temperature on development of each life stage, adult longevity and fecundity of P. brassicae at four constant temperatures of 15, 20, 25 and 27.5℃ for immature life stage and five constant different temperatures of 10, 15, 20, 25 and 27.5℃ for adult stage. Eggs and larvae successfully developed next life stage at temperature tested. The development period of egg, larva, and pupa decreased as temperature increased. Lower developmental threshold (LDT) and thermal constant (K) were calculated using linear regression as 8.7℃ and 344.73DD, respectively. Lower and higher threshold temperature (TL and TH) from egg to adult emergence were estimated by Briere function as 5.3℃ and 40.4℃, respectively. Adults produced eggs at the temperature range between 10℃ and 27.5℃, and showed an estimated maximum number, ca. 627.5 eggs at 21.7℃. Adult oviposition models including aging rate, age-specific survival rate, age-specific cumulative oviposition, and temperature-dependent fecundity were constructed. Temperature-dependent development models and adult oviposition models would be useful components to understand the population dynamics of P. brassicae and to establish the strategy of integrated pest management in cruciferous crops.

• Korean journal of applied entomology
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• v.59 no.2
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• pp.93-107
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• 2020

Adults of seven noctuid potential pests (Spodoptera frugiperda, S. litura, S. exigua, Ctenoplusia agnata, Mythimna loreyi, Athetis dissimilis, and A. lepigone) of soybean and maize in Suwon, Korea were identified by their morphological characteristics in the wing pattern and male genitalia and partial mitochondrial DNA sequences of cytochrome c oxidase subunit 1 gene. The generation number of adults that emerge annually in six species (except A. lepigone) was estimated from the data on density fluctuations of adults caught in sex pheromone traps in 2019 and the forecasted data using temperature-associated development and reproduction models for those species. S. frugiperda adults were caught from July 27th to October 31st in 2019, and hence were initially estimated to emerge three times per year. But, it was finally expected that S. frugiperda adults could possibly emerge a total of four times per year in Suwon, considering larval emergence observed during mid- and late June in other areas. Adult emergence of S. litura, S. exigua, C. agnata, and M. loreyi in 2019 was observed from May 29th to November 6th, from May 14th to November 6th, from May 26th to October 25th, and from May 31st to November 23rd, respectively. Annual adult emergence of these four species was estimated as at least four times. Adults of A. dissimilis were caught from May 26th to September 11th in 2019, and adult emergence was estimated at only twice per annum. It was postulated that the first adult populations of five species except the two Athetis species were probably migrated from other areas.