• The Korean Journal of Pesticide Science
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• v.15 no.1
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• pp.1-7
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• 2011

In order to enhance the fungicidal activity of the thifluzamide formulation against rice sheath blight, the surfactants which was able to facilitate the foliar uptake or increase the leaf deposit of thifluzamide on rice plants were selected, and the formulations containing the surfactants were tested to compare the fungicidal efficacy against the rice sheath blight with a control WP formulation. The WP suspension containing dodecaethylene glycol monohexadecyl ether as an activator increased the foliar uptake of thifluzamide on rice plants, but its fungicidal efficacy against rice sheath blight was decreased. The addition of the combined surfactants with either heptaethylene glycol monoisododecy ether or heptaethylene glycol monotridecyl ether and sodium dioctylsulfosuccinate to WP suspension increased the leaf deposition of thif1uzamide at around 5 times of that without a spreader-sticker that median control concentrations of thifluzamide against rice sheath blight were decreased to 4.4 mg $L^{-1}$ and 3.4 mg $L^{-1}$, respectively.

• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.401-406
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• 2010

This study was conducted to investigate the control effects of the environmental-friendly materials against major diseases of pear and to elucidate factors related to spore disperse of pear scab and pear rust. Spore disperse was deeply related ambient temperature in the early stage of disease occurrence and the maximum spore disperse was affected greatly by the air humidity, Percent of infected leaves of pear scab in plot treated with Trichoderma harzianum-YC459 was 29.3% and 43.3% in plot treated with Sulfur-80%. Two formulations above-mentioned were less effective to control pear scab than the chemical pesticide, hexaconazole. Control effect in plots single- and mixed-treated with Trichoderma harzianum-YC459, Sulfur-80% and hexaconazole against pear scab were compared with that in plot treated with chemicals by conventional application schedule in pear orchard. The incidence of pear scab was lower in plot treated with the environmental-friendly materials than that of untreated plot. However there was no significant difference among the treatments at the 5% level. Application of Sulfur-80% reduced significantly the incidence of pear scab (7.8%) compared to that (10.3%) in plot treated by conventional application schedule in organically cultivated pear orchard. Alternative application of Trichoderma harzianum-YC459 and Sulfur-80% (4.3%) suppressed the incidence of pear rust than that (7.1%) in plot treated by conventional application schedule in organically cultivated pear orchard.

• The Korean Journal of Pesticide Science
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• v.3 no.1
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• pp.90-95
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• 1999

For the control of the greenhouse whitefly, Trialeurodes vaporariorum entomopathogenic fungi were isolated from forest soils and infected insects. We selected three strains, which showed high pathogenicity and named as SFB-582(Beauveria sp.), SFP-198(Paecilomyces fumosoroseus) and SFV-1053(Verticillium sp.) respectively. Particularly, at the concentration of $10^{7}$ conidia/ml, P. fumosoroseus SFP-198 had the highest pathogenicity, $91.4{\pm}3.5%$ in laboratory. In glasshouse application, $91.4{\pm}3.5%$ SFP-198 showed high protective values($80{\sim}90%$) regardless of developmental stages, which were similar with that of Verticillium lecanii F-903 already reported. Four kinds of formulations of entomopathogenic fungi were developed, formulation with surfactant Silwet L-77 gave best control of greenhouse whitefly(over 90%). These results suggest that P. fumosoroseus SFP-198 is a promising candidate as a microbial pesticide for the control of T. vaporariorum.

• Journal of Apiculture
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• v.34 no.4
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• pp.305-313
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• 2019

Honey bees (Apis mellifera) forage in agricultural areas, and are exposed to diverse pesticide poisoning. Toxic effects on Apis mellifera of different groups of pesticides were tested in the laboratory; fungicide (Metconazole), herbicide (Glyphosate), acaricide (Amitraz), organophosphate insecticide(Fenitrothion) and neonicotinoid insecticides(Thiacloprid, Thiamethoxam, Imidacloprid, Acetamiprid, Dinotefuran and Clothianidin). Commercial formulations were serially diluted from the recommended concentration (RC) to 10-6 times to carry out feeding and contact tests. Toxicity was transformed into lethal dose (LD50) and hazard question (HQ). The acute toxicity of pesticides showed similar patterns between feeding and contact tests. But feeding tests showed greater toxic to honey bee than contact test. The organophosphate and nitro-neonicotinoid insecticides were highly toxic with HQ values ranging greater than 1. However, cyano-neonicotinoids of Thiacloprid and Acetamiprid showed low toxicity. Even at the RC, 24 hr mortalities were 18 and 30%. The acaricide (Amitraz) showed intermediate level of toxicity at RC but negligible at the concentration lower than 10-1 times. A fungicide(Metconazole) and herbicide(Glyphosate) showed minimal impacts. The results imply that the selective use of pesticides could help conservation of pollinators in agricultural production systems.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.401-410
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• 2005

A series of studies involving formulation processes, bubbling activity test, diffusibility test and biological efficacy test was undertaken to develop Jumbo herbicide formulations in paddy rice field. Gas evolution speed from the tablets prepared by different organic acids was in the order of oxalic acid, malonic acid, citric acid, and tartaric acid. The total volume of evolved gas from the tablet and diffusibility of the active ingredient in the submerged water were increased with increase of water temperature; the volume from 1 g of tablet at 10, 15, 25 and $30^{\circ}C$ for 5 minutes after immersion into water was 20, 25, 28, 45, 57 mL, respectively. The concentration of halosulfuron-methyl and pyriminobac-methyl in submerged water at 5, 15, 20 and $30^{\circ}C$ at the 2.4 m distance from the applied spot of the tablet was 20, 48, 85, and 97% of the concentration of treated spot, respectively. The evolved gas volume from the tablets was not affected by pH of submerged water. The concentration of halosulfuron-methyl in different sizes of submerged water within 24 hours after treatment of the tablet was maintained 0.16 ppm, which is ideal concentration at standard dosage regardless of the submerged water area. The concentration of pyriminobac-methyl was also uniformly dispersed in the water within 24 hours after applying it into the submerged water. The wind velocity of 5 m $sec^{-1}$ on concentration distribution of halosulfuron-methyl and pyriminobac-methyl in the submerged water 24 hours after treatment was not influenced; an equal concentration in the up the wind and down the wind from the applied spot was maintained. Spot treatments of one tablet formulations(5 g) including 4 times higher dosage at 4 different spots resulted in even concentration distribution of active ingredient in the water 24 hours after applying it into the submerged water.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.137-146
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• 1998

Laboratory tests were carried out to evaluate the effect of several insecticides with insect growth regulator (IGR) properties on the larval development of housefly, Musca domestica, which was collected at a large pigpen in Hamyang, Gyeongnam, Korea in 1997. Commercial formulations of the chemicals were diluted with tap water into a range of concentrations, and mixed with larval media. In addition to the IGRs, imidacloprid 5% WP was tested, too. The IGRs treated at the 2nd instar stage induced higher larval mortalities than percentages of malformed pupae. The result were, however, opposite when the IGRs were treated at the 3rd instar stage. Overall mortality resulting from larval death and malformed pupae was dependent on concentration. Diflubenzuron, teflubenzuron, triflumuron, flufenoxuron, tebufenozide, and imidacloprid, treated to the 2nd instar larvae, showed mortality over 95 % at concentrations of 5 ppm, 3 ppm, 30 ppm, 5 ppm, over 1000 ppm, 1000 ppm, respectively. Higher concentrations were needed to get the same level. of mortality in the 3rd instar larvae as that in the 2nd larvae. Overall mortality over 95% at the 3rd instar could be get at concentrations of 100 ppm, 10 ppm, 300 ppm, 10 ppm of diflubenzuron, teflubenzuron, triflumuron, flufenoxuron, respectively. Tebufenozide (1,000 ppm) and imidacloprid (300 ppm) were less effective than the other chemicals, showing only 36.7% and 86.7% mortalities, respectively. The chemicals also affected pupal weight at high concentrations. Decrease of pupal weight was distinct at high concentrations of teflubenzuron, flufenoxuron, tebufenozide, imidacloprid. Diflubenzuron and triflumuron were less effective. From these results it could be concluded that the IGR insecticides can be used as control agents by interfering with moulting and pupation process of housefly, by reducing pupal weight which could be resulted in low fertility and less oviposition.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.83-92
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• 2016

New tree wound-treatment formulations (WTF) were developed in this study. Stimulating effects of plant growth regulating substance on callus formation were evaluated in vivo twig disc culture of Zelkova serrata, Ziziphus jujuba, Pinus densiflora, Ginkgo biloba. and Aesculus turbinata. Based on the evaluation, WTF were prepared with 2,4-D, NAA, and IBA using xanthan gum as an extending agent. WTF were pasted on $2{\times}10cm$ artificial wound on the stem and the effects were evaluated 12 weeks later with the thickness of new callus-tissues. The effects varied with tree species and the growth regulators. In Z. serrata and A. turbinata, 2 mg/L of 2,4-D was the best WTF. In P. koraiensis and G. biloba, 8 mg/L of NAA and 1 mg/L of IBA were the best, respectively. Callus formation was quite lower in G. biloba compared to other species. Stimulating effect of thiophanate-methyl paste was excellent only in Z. serrata and lower than certain WTF in other species. Vaseline, which was used generally as an WTF, remained longer on the wound and causing decay. From the results, it could be recommended that 2,4-D, NAA and IBA were the best WTF for Z. serrata/A. turbinata, P. koraiensis and G. biloba, respectively.

• The Korean Journal of Pesticide Science
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• v.9 no.3
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• pp.243-249
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• 2005

The chemical and toxicological studies were conducted with acetamiprid 2% granules including different controlling agents for development of controlled-release acetamiprid 2% granule. The fundamental formulation recipe of acetamiprid 2% granule was prepared by the insoluble matrix using polyethylene wax. Starch, cellulose and mineral (calcium carbonate) were used as controlling agents. As a result of studies, release rate of active ingredient from granules into water static condition at $25^{\circ}C$ was increased by addition of starch and cellulose, but was decreased by addition of calcium carbonate. We could select calcium carbonate as controlling agent and make three granules which there were difference in release profiles of active ingredient according to contents of polyethylene wax. 24 hours-release rates of acetamiprid from three granules into water static condition at $25^{\circ}C$ were respectively 75, 50 and 25% when contents of wax were 2, 10 and 20%. The granule which 24 hours-release rate was 25% showed lower acute toxicity against mice and rats.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.325-331
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• 2004

The studies were undertaken to establish optimum formulation recipes of acetamipid 4% SL(soluble concentrate) using different adjuvants and to evaluate enhanced control effect on target insect pests by adjuvants. Adjuvants for the studies used were SS(Sodium alkylcarboxylate) and PE(Polyoxyethylene alkyl ether). After the fundamental recipe for SL being established by using co-solvent for stability at low temperature, four types of SL were formulated. The physical properties and insecticidal efficacies of the tested SL formulations were investigated. Surface tension of SL1 without adjuvant was highly decreased from 44 dyne/cm to 34 dyne/cm by addition of adjuvants. SL4 using mixed adjuvant showed the lowest contact angle. Efficacies of SL1 without adjuvant against the palm thrips (Thrips palmi) and the cotton aphid (Aphis gossypii) on cucumber were increased by adding adjuvants. SL4 using mixed adjuvant showed higher efficacy than SL2 and SL3 using single adjuvant. These results have demonstrated that the selected adjuvants could be used to enhance insecticide efficacy and reduce spray dose of insecticide.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.60-69
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• 2005

The herbicide molinate has been detected with high frequency in the main river during the growing season in Korea. To elucidate the exposure of molinate in agricultural environment, the persistence and the degradation characteristics of molinate were investigated in paddy ecosystems. The half-lives of molinate were 4.1 days with soil aquatic system, and 4.2 days in only aquatic system. Initial dissipation rate of molinate in water was greater with soil aquatic system than that of only aquatic system. Photolysis of molinate was occurred about 31.0% of molinate treated in pure water, when irradiated at 5,530 $J/cm^2$ by the xenon lamp, but its hydrolysis was stable. For the accelerated photolysis of molinate in aqueous solution, several photosensitizers were screened, showing that the hydroperoxide($H_2O_2$) and acetone were prominent among the chemical tested. When hydroperoxide and zinkoxide(ZnO) were used as photosensitizer, their photolysis were accelerated greater than 98% and 58% in aqueous solution, respectively. Elution rate of molinate as granular formulations in aqueous system was more than 90% in 30 hour at $35^{\circ}C$. Molinate concentration pattern in paddy water was rapidly decrease from treatment till 7 days in paddy rice field and its half-lives were 3.7 days($Y=1.9258{\times}e^{-0.1865X}$(r=-0.9402)).