• Korean journal of applied entomology
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• v.31 no.3
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• pp.289-303
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• 1992

Investigation of the environmental impact of widespread pesticide use has revealed a virtue/vice relationship. Although many pesticides perform their function and disappear without harm to the environment, others persist beyond their useful purpose and cause direct of indirect hazard to man, domestic animals and wildlife. Concurrently, many pests have rapidly adjusted to chemical control practices through changes in behavior that avoid exposure to pesticides of throuth genetic selection for populations resistant to the toxicants. The prospect of losing control over insect herbivores and desease vectors and returning to the days of global hunger and disease is unthinkable. Fortunately, from basic studies of insect and plant biology many opportunities for the development of safe, selective and environmentally pacific strategies for insect pest management are being realized.

• Korean Journal of Environmental Agriculture
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• v.29 no.1
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• pp.39-46
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• 2010

Environmental-friendly agriculture (EFA) is defined as the cultivation of crops with reduced amounts or without chemical-synthetic pesticides. Recently, the use of chemical pesticides has decreased significantly; therefore, we cultivated peppers following EFA- and conventional methods and compared their antioxidant activities. To accomplish this, the environmental-friendly cultivated peppers (EFPE) and conventionally cultivated peppers (CCPE) were extracted with 70% methanol and the effects of the extracts on the cell viability, intracellular ROS generation, lipid peroxidation and catalase activity of HepG2 cells were evaluated. EFPE showed a stronger protective effect against oxidative stress induced-cell death than that of CCPE. EFPE also reduced intracellular ROS generation (42.7% to 26.4%) following treatment with hydrogen peroxide more effectively than that of CCPE (24.2% to 6.3%). Furthermore, EFPE and CCPE showed protective effects against lipid peroxidation and induced catalase activity, although these effects were not statistically significant. Taken together, these results suggest that EFPE showed stronger antioxidant activities than CCPE, and thus represent evidence that EFA with biocontrol materials may improve the functional properties of crops and/or secondary metabolites with antioxidant activities when compared with conventional agricultural practices.

• Journal of Applied Biological Chemistry
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• v.57 no.4
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• pp.341-345
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• 2014

Fate of fenarimol, chlorothalinol, and ethoprophos sprayed to control disease and pest was studied in a agroforest culture field of Jangsu-gun, Jeollabuk-do, Korea. Concentrations of fenarimol, chlorothalinol, and ethoprophos in runoff water ranged mostly to 0.2 mg/L at the first rainfall-runoff event. And then was rapidly decreased than detection limit at 60 days after the application. The fenarimol and chlorothalonil residue in soil was dissipated to below detection limit at 30 days after the application. But ethoprophos was decreased to below detection limit at 135 days after the application. The concentrations of experimental pesticides were highly detected in agroforest culture field than in open culture field. It is assumed that experimental pesticides were strongly adsorbed by organic matter such as fulvic acid and humic acid.

• The Plant Pathology Journal
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• v.25 no.4
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• pp.376-380
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• 2009

Effects of silver nanoparticles on the phytopathogenic fungal growth were investigated. Fungal phytopathogens, especially for sclerotium-forming species Rhizoctonia solani, Sclerotinia sclerotiorum and S. minor, were selected due to their important roles in survival and disease cycle. Tests for the fungal hyphal growth revealed that silver nanoparticles remarkably inhibit the hyphal growth in a dose-dependent manner. Different antimicrobial efficiency of the silver nanoparticle was observed among the fungi on their hyphal growth in the following order, R. solani > S. sclerotiorum > S. minor. Tests for the sclerotial germination growth revealed that the nanoparticles showed significant inhibition effectiveness. In particular, the sclerotial germination growth of S. sclerotiorum was most effectively inhibited at low concentrations of silver nanoparticles. A microscopic observation revealed that hyphae exposed to silver nanoparticles were severely damaged, resulting in the separation of layers of hyphal wall and collapse of hyphae. This study suggests the possibility to use silver nanoparticles as an alternative to pesticides for scleotium-forming phytopathogenic fungal controls.

• Environmental Engineering Research
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• v.23 no.2
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• pp.223-227
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• 2018

This study reports a cyanide resistant and/or tolerant fungus, isolated from the rhizosphere of Zea mays contaminated with cyanide-based pesticides. The isolate was characterised using molecular biology. The effect of free cyanide and heavy metals on the growth of isolate in a synthetic gold mine wastewater was examined. The molecular analyses identified the isolate as Fusarium oxysporum EKT01/02 (KU985430/KU985431). The isolate had a free cyanide degradation efficiency of 77.6%. The results indicated greater growth impairment in culture containing Arsenic (optical density 1.28 and 1.458) and cyanide (optical density 1.315 and 1.385). Higher growth was observed in all cultures supplemented with extracellular polymeric substance. This study showed that the isolate possesses wide substrate utilisation mechanism that could be deployed in environmental engineering applications.

• Korean Journal of Environmental Agriculture
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• v.29 no.1
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• pp.72-76
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• 2010

We have developed the bio-electrode measuring the variance of the amount of acetylcholine affected by residual pesticide. The working electrode of the biosensor was made by combination of cobalt phthalocyanine and carbon organic compounds. The biosensors were constructed by screen-printing method. The principle of working electrode is similar to thiocholine sensor. We have fabricated the biosensor using standard screen printing method. Generally, the biosensor made by printing method formed thick film biosensor. When the electrodes were made by electrochemical cells, the generation of current by the addition of enzyme substrate was inhibited by standard solutions of organo-phosphate pesticides. The detection limit of sensor is about 0.5 $\mu{g}/L$ for carbofuran. We could improve the responsibility of the sensor by controlling the cobalt phthalocyanine and thiocholine concentration ratio. Also we have tested the EPN and Chlorpyrifos pesticides and found that the biosensor is applicable to fast determination of residual pesticides.

• The Korean Journal of Pesticide Science
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• v.6 no.1
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• pp.16-24
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• 2002

Research trends in the measurement of foliar uptake of pesticides and the recently proposed action mechanism of the surfactant-induced uptake of pesticides were reviewed with the related reports and studies. Major techniques used in those fields are bioassay, radiotracer techniques with leaves or cuticular membrane. Recently, a new method using Congo Red as a tracer was proposed. The limiting factor in the pesticides uptake into leaves is the waxy layer which consists of the epicuticular and cuticular wax. Physico-chemical parameters such as molar volume, water solubility and partition coefficient of pesticides have limited influences on the pesticide uptake into leaves. Polydisperse ethoxylated fatty alcohol surfactants are well known as the good activator for many pesticides. It is now generally agreed that uptake activation is not related to the intrinsic surface active properties of surfactants such as surface activity, solvent property, humectancy and critical micelle concentration. Recent studies using ESR-spectroscopy revealed that the surfactants have an unspecific plasticising effect on the molecular structure of the wax and cuticular matrix, leading to increased mobilities of pesticides. Penetration of surfactants into waxy layer altered the pesticide mobility in wax and the partition coefficient of pesticide, and then the pesticides penetration into leaves was enhanced temporally. The enhancing effect of surfactant could be significantly different depending on the carbon number of aliphatic moiety and the number of ethoxy group in polyoxyethylene chain of surfactants. It is suggested that the rate of penetration of surfactants should have a significant relationship with the rate of penetration of pesticides.

• Journal of Bio-Environment Control
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• v.20 no.2
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• pp.101-108
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• 2011

The small and medium sprayer has developed to spray well fruit trees and roadside trees with pesticides for pests control within 60 meters. This study was carried out to analyze and evaluate its performance using image processing. While it sprayed with pesticides on the area of 20m in width and 60m in length, it was experimented 5 places by 5m from 0 to 25m width and 6 places by 10m from 10 to 60m length. The experimental image data of each sheet on places were averaged after binarization process. According to the image data, it was sprayed on all working area. However, when sprayer moved 0.3m/s velocity, the place at 15m of width and 30m of length was sprayed more than any other sprayed area, but the place at 15m of width and 60m of length was sprayed less.

• The Korean Journal of Pesticide Science
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• v.13 no.4
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• pp.249-255
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• 2009

In order to calculate the processing and reduction factor between fresh and dry Welsh onion which was widely used as a dried agricultural ingredient of food in Korea. 7 pesticides such as pyridalyl, kresoxim-methyl, spinosad, flufenoxuron, difenoconazole, metconazole, and tebufenozide were tested. After 2 sites field trial conducted and measured water contents by drying at $60^{\circ}C$ and analyzed the pesticide residue. Water contents of fresh and dried Welsh onion are 89.2 and 10.2% respectively. Averages of processing factor showed 7.24 of pyridalyl, 2.85 of kresoxim-methyl, 7.43 of spinosad, 3.17 of flufenoxuron, 4.38 of difenoconazole, 2.40 of metconazole and 8.13 of tebufenozide into 2 field samples. Averages of Reduction factor showed 0.87 of pyridalyl, 0.35 of kresoxim-methyl, 0.88 of spinosad, 0.38 of flufenoxuron, 0.52 of difenoconazole, 0.29 of metconazole and 0.98 of tebufenozide. Residual amounts of pesticides in/on fresh Welsh onion reduced during drying process.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.487-490
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• 2006

Because of consumer rejection of chemical pesticides and the appearance of microorganisms that are resistant to fungicides, we tried to discover biopesticides. Of 13 microorganisms isolated from Shrimp-jeotkal, a Bacillus sp. showed strong activity against tomato late blight caused by Phytophthora infestans. Its activity was tested both in vivo and in vitro. The identification of the strain was carried out based on 16S rDNA analysis and the morphology by scanning electron microscopy.