• Korean journal of applied entomology
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• v.51 no.4
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• pp.357-364
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• 2012

This study was conducted to observe the influence of chemical pesticides and environmentally friendly agricultural materials (EFAMs) used in tomato cultivation on the pathogenicity of the entomopathogenic fungus, Beauveria bassiana. B. bassiana mycelium didn't grow on PDA media containing 13 fungicides including chlorothalonil and colonies were not formed on PDA media containing 12 fungicides. B. bassiana mycelium grew and colonies were formed on all PDA media containing insecticides and EFAMs, but mycelial growth and colony formation on most PDA media were significantly inhibited compared to the control. The insecticidal activity of B. bassiana against Trialeurodes vaporariorum was decreased when fungicides (polyoxin B, mandipropamid) and EFAMs containing sulfur were added, but insecticides (pyridaben, dinotefuran) and EFAMs originated from plant extracts did not have any influence on the insecticidal activity of B. bassiana. The pathogenicity of a mixture of B. bassiana and polyoxin B against T. vaporariorum was lower than that of B. bassiana alone under greenhouse conditions.

• International Journal of Industrial Entomology and Biomaterials
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• v.18 no.2
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• pp.105-112
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• 2009

The greenhouse whitefly, Trialeurodes vaporariorum (Westwood) and the sweet potato whitefly, Bemisia tabaci (Gennadius) are serious insect pests that have a wide host range including cucumber, tomato, and pepper. In this study, we tested larvicidal efficacy of several on-the-market environment-friendly agricultural materials (EFAM) to select the effective products after the target pests were stabilized in indoor rearing condition. The developmental periods of two whiteflies are as follows: in the case of T. vaporariorum, egg duration is 9.6 days and nymph is 18.9 days, and in the case of B. tabaci, egg duration is 7.4 days and nymph is 15.2 days under $25^{\circ}C$ with relative humidity (RH) of $60{\pm}5%$ and a photoperiod of 16 L:8D. The total period of T. vaporariorum was 5 days longer than B. tabaci. Among 22 EFAMs six products showed more than 60% of insecticide efficacy against T. vaporariorum BTV B, BTV D, BTV G, BTV L, BTV M, and BTV S. On the other hand, seven EFAM products showed over 60% of insecticide efficacy against B. tabaci BTV D, BTV G, BTV K, BTV L, BTV M, BTV N, and BTV U. In the case of Spodptera litura previously, 16 EFAMs were tested against $2^{nd}$ instar S. litura, and six EFAMs were found to have more than 90% efficacy. Test of these six EFAMs against entire larval stages were performed in this study. Although some of these products showed still more than 90% of insecticidal efficacy against up to $3^{rd}$ instar larvae, the efficacy of these EFAMs sharply decreased as ages increase, resulting in less than 60% of efficacy of the products at most. This result indicates the difficulty to control S. litura with the on-the-market EFAMs alone under economic injury level. Collectively, it is required to find more EFAMs, and find alternative method, and combined way of controlling to control those insect pests tested in this study.

• Research in Plant Disease
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• v.26 no.4
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• pp.210-221
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• 2020

This research was executed to select beneficial antagonists from digestive organ of Allomyrina dichotoma larva that can be put on environment friendly control against phytopathogenic fungi. We screened 38 bacterial strains inhibiting mycelial growth against eight plant pathogens through dual culture assay. The 10 strains among 38 bacterial strains were selected as beneficial microbes showing antifungal activity against Botrytis cinerea, Plasmodiophora brassicae, Colletotrichum acutatum and Phytophthora capsici through under greenhouse pot trials. The 10 bacterial strains that shown strongest antifungal activity were classified into 3 genera and 10 species, and identified as the genus Bacillus (DM146, DM152, DH2, and DH16), Paenibacillus (DF30, DH14, and DM142) and Streptomyces (DF137, DM48, and DH92) by morphological characteristics and 16s rRNA gene sequence. The 10 bacterial strains had solubilizing activity of insoluble phosphates, production of IAA (indole-3-acetic acid), β-1,3-glucanase and protease. Among the 10 bacterial strains, DM152 strain was produced significant enhancement of all growth parameters of chili pepper and tomato seedlings under greenhouse condition. Thus, this study demonstrated that gut microbes of Allomyrina dichotoma larva will be useful as a potential biocontrol agent against plant pathogens and biofertilizer.

• Korean journal of applied entomology
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• v.62 no.4
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• pp.355-363
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• 2023

In addition to causing direct feeding damage to a variety of greenhouse crops, Frankliniella occidentalis also inflicts indirect harm by facilitating the transmission of the tomato spotted wilt virus. Historically, the prevention of F. occidentalis infestations has relied heavily on pesticide use. However, this approach has led to significant side effects in agricultural ecosystems, including the development of pest resistance and challenges in effective prevention. In response to these issues, research has been directed towards identifying alternative substances that circumvent the tolerance developed against chemical pesticides. Extracts from sixty-seven medicinal plants were prepared by soaking them in water for 24 hours at room temperature. These extracts were then applied to adult F. occidentalis, with particular attention to moutan extract treatment. This treatment demonstrated a 100% insecticidal effect on the first day. The moutan extract, specifically, was prepared using 50% ethanol, after which the ethanol and water were removed via a rotary evaporator. The resultant product was then lyophilized into a powder and used after being diluted with water. In indoor experiments, a 40% diluted solution was sprayed onto F. occidentalis, exhibiting a 100% insecticidal effect 24 hours post-treatment. Furthermore, a pot test indicated a 78% insecticidal effect on the first day of application. Ongoing research includes the analysis of active substances that demonstrate exceptional insecticidal properties and the conduct of on-site validation tests. The application of the aforementioned extract is anticipated to be effective in the prevention of F. occidentalis infestations.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.143-143
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• 2017

산업이 고도화됨에 따라 자동화 기계 및 로봇에 의해 대량 생산 되는 품목과 달리, 작업 절차의 비정형성, 비연속성 등으로 인해 여전히 농업에 많은 인력이 투입되고 있다. 국제노동기구에 따르면, 세계 인력의 절반이 농업 인력에 해당하고 작업 중 부상이나 사망 등으로 인해 가장 위험한 직업군 중 하나에 해당하는 것으로 나타났다. 시설 재배 농업의 경우, 노동집약적인 온실 내 작업 특성상 잘못된 자세로 작업하거나 지나친 작업량 등으로 인해 작업자에게 근골격계 질환이 발생할 수 있다. 근골격계 질환으로 인해 작업효율이 감소하거나 생산비용의 증가로 이어질 수 있으며, 농가 수익에 손실이 발생할 수 있다. 이에 본 연구에서는 현행 시설 재배 농업에서 사용되는 레일 전동 작업차를 이용하여 작업자가 토마토를 수확할 때의 신체에 대한 농작업의 부하를 평가하고자 하였다. 작업차를 이용한 주요 작업 절차는 작물로부터 과실 수확, 과실 상자에 과실 투입, 빈 과실 상자와 가득 찬 과실 상자의 교대, 작업차 위의 과실 상자를 운반용 파레트에 하역하는 순서로 이루어지는 것을 확인하였다. 비디오장비로 촬영된 일련의 농작업 과정을 OWAS, RULA, REBA와 같은 체크리스트형 인간공학적 작업 부하 평가 도구를 이용하여 평가한 결과, 기존 레일 전동 작업차를 이용한 농작업의 근골격계 질환 유발 가능성을 확인하였다. 동작별 위험성을 토대로 근골격계 질환 유발 가능성이 높아 개선이 필요한 농작업 동작을 선정하였다. 선정된 동작은 실험실 내 환경에서 피실험자를 통한 모의 동작의 생체 신호 계측을 통해 신체 부하 정도를 정량적으로 측정할 수 있으며, 보조가 필요한 신체 부위를 특정하거나 안전성 확보가 필요한 동작에 대한 증거가 될 수 있다. 본 연구를 통해 향후 토마토 온실 내 신선도 유지를 위한 레일 전동 작업차의 개발에 작업자의 안전과 효율성 향상을 위한 인간공학적 설계를 적용할 수 있을 것으로 기대한다.

• Korean Journal of Organic Agriculture
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• v.28 no.3
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• pp.417-430
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• 2020

Drought stress is one of major environmental stresses in plants; this leads to reduce plant growth and crop yield. In this study, we selected fungal isolate for mitigating drought stress in pepper plants. To do this, 41 fungi were isolated from rhizosphere or bulk soils of various plants in Jeju, Gangneung, Hampyeong in Korea. Out of 41 isolates, we screened two isolates without phytotoxicity through seed germination of tomato, pepper, and cabbage treated with fungal spores; through following plant assay, we selected GL02 as a candidate for alleviating drought stress in pepper plants. As a result of greenhouse test of pepper plants in drought condition, the stomatal conductance on leaves of pepper plants treated with GL02 was increased, whereras the malondialdehyde (MDA) and electrolyte leakage were decreased compared to that in control plants. When stressed plants were rewatered, stomatal conductance of the plants treated with GL02 was increased; the electrolyte leakage was decreased. Based on internal transcribed spacer (ITS) sequencing analysis, isolate GL02 was belonging to genus Trichoderma. Taken together, drought stress in pepper plants treated with GL02 was alleviated, when it was rewatered after drought-stressed, the plants could be recovered effectively. Therefore, Trichoderma sp. GL02 could be used as a bio-fertilizer to alleviate drought stress in pepper plants.

• Research in Plant Disease
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• v.12 no.3
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• pp.267-271
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• 2006

Botrytis cinerea Pers. was found to be highly virulent to the grapevine plant, especially in greenhouse condition. Pseudomonas species play key roles for the biocontrol of many plant diseases especially in soil. Of the 83 isolates of Pseudomonas spp., a bacterial strain P84, isolated from tomato rhizosphere, was shown to suppress a wide range of phytopathogenic fungi in vitro. The isolate was identified as Pseudomonas putida on the basis of its bacteriological and genetic characteristics. The P. putida P84 strain carry the phlD gene for 2,4-diacetylphloroglucinol biosynthesis and may produce the antibiotics as an antagonistic mechanism involved in biocontrol. The antagonistic activity of the bacterium has a promising implication for its use as a biocontrol agent to control grapevine gray mold.

• Research in Plant Disease
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• v.11 no.2
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• pp.167-172
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• 2005

An isolate of Ampelomyces quisqualis 94013 was selected as an effective parasite for biological control against cucumber powdery mildew. Temperature range for the parasitism of A. quisqualis 94013 against cucumber powdery mildew was $12\~30^{\circ}C$, and optimal temperature for that $20\~28^{\circ}C$. In $20\~35\%$ humidity of the greenhouse, parasitic ability of A. quisqualis 94013 against Sphaerotheca fusca was not good. Inoculation tests revealed that A. quisqualis 94013 can parasitize on six species of Sphaerotheca in the 12 crops and Ersiphe cichoracerum in tomato. As host rang of A. quisqualis 94013 was broad and it may be used effectively as a biocontrol agent for powdery mildew of 13 crops.

• Mycobiology
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• v.41 no.4
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• pp.234-242
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• 2013

A total of 62 bacterial isolates were obtained from Gomsohang mud flat, Mohang mud flat, and Jeju Island, Republic of Korea. Among them, the isolate CNU114001 showed significant antagonistic activity against pathogenic fungi by dual culture method. The isolate CNU114001 was identified as Bacillus amyloliquefaciens by morphological observation and molecular data analysis, including 16SrDNA and gyraseA (gyrA) gene sequences. Antifungal substances of the isolate were extracted and purified by silica gel column chromatography, thin layer chromatography, and high performance liquid chromatography. The heat and UV ray stable compound was identified as iturin, a lipopeptide (LP). The isolate CNU114001 showed broad spectrum activity against 12 phytopathogenic fungi by dual culture method. The semi purified compound significantly inhibits the mycelial growth of pathogenic fungi (Alternaria panax, Botrytis cinera, Colletotrichum orbiculare, Penicillium digitatum, Pyricularia grisea and Sclerotinia sclerotiorum) at 200 ppm concentration. Spore germ tube elongation of Botrytis cinerea was inhibited by culture filtrate of the isolate. Crude antifungal substance showed antagonistic activity against cucumber scleotiorum rot in laboratory, and showed antagonistic activity against tomato gray mold, cucumber, and pumpkin powdery mildew in greenhouse condition.

• Journal of Bio-Environment Control
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• v.2 no.1
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• pp.27-36
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• 1993

Carbon dioxide enrichment for greenhouse crops has generally been a standard commercial practice for many years. Vegetable crops such as tomato, cucumber, and lettuce respond positively to the $CO_2$ enrichment. But improper $CO_2$ enrichment leads to physiological damage and economical loss. This study was carried out to develop a $CO_2$ concentration control algorithm considering growth stage and efficiency. The measurand was $CO_2$ consumption rate and top fresh weight that represents growth stage. The weight of top fresh lettuce as a whole in the tray was measured through a non-destructive method. The demand in $CO_2$ concentration according to growth stage was investigated. The results are summarized as follows. 1. The $CO_2$ consumption rate could be measured within the error of $\pm$ 15.4mg$CO_2$/hr in the range of $CO_2$ concentration of 500-1500ppm. 2. The weight of top fresh lettuce could be measured within the error $\pm$ 4.3g in the range of 0-1400g. 3. The $CO_2$ control model developed could determine an economical $CO_2$ supply rate considering $CO_2$ consumption rate and leakage rate. 4. The $CO_2$ control algorithm based on the control model was composed of feedforward control for maintaining a stable $CO_2$ concentration level, and feedback control with $CO_2$ consumption rate and top fresh weight for adapting to the change in $CO_2$ demand by growth stage. 5. For the performance test with the developed control algorithm on lettuce the decrease in $CO_2$ supply rate was obtained without a significant decrease in top fresh weight.