• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.119-125
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• 1998

A nation-wide fact-finding survey was done to provide the basic information for establishing the rational weed control scheme in paddy rice. A total of 445 respondents including 273 farmers and 172 pesticide dealers was involved in this survey. Dominant weeds in rice paddy field were Echinochloa crus-galli, Eleocharis kuroguwai, Sagittaria pygmaea, Sagittaria trifolia, etc.. Preferred herbicides widely used by farmners were ranked in the following order; butachlor 5GR, pyrazosulfuron-ethyl + molinate 5.07GR, molinate + cinosulfuron 5.08GR, meanwhile, those recommended by pesticide dealers were; pyrazosulfuron-ethyl + molinate 5.07GR, molinate + cinosulfuron 5.08GR, and butachlor 5GR. The guidelines to choose the preferred herbicides was primarily based on the experience, which was occupied about 45%. Approximately 56% of the farmers followed the recommended herbicide dosage and 43% of them applied the herbicides before weed germination (pre-emergence treatment). In addition, most farmers applied herbicides at least two times with systematic application schedule. Application method of granular formulation was broadcasting by hand, while that of sprayable ones was by high-pressure sprayer. Some farmers answered that they had experienced phytotoxicity in the crop by applied herbicides, of which higher experience was observed from the farmers who applied by high-pressure sprayer. It was analyzed significantly that the feasible herbicides to cause phytotoxicity in rice at farmer's level were butachlor 5GR, esprocarb + pyrazosulfuron-ethyl 5.07GR and bensulfuron-methyl + molinate 5.17 GR.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.36-44
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• 1998

To develope cost-effective new granular formulation of mixture with 7.0% chlomethoxyfen and 3.5% butachlor, this study was conducted by investigation of floatability, dispersibility or collapsability and released concentration of active ingredients in water and bio-efficacies of the granules formulated by different formulation methods compared to commercial pellet-extruded granules. They were formulated by coating on or impregnation into extruded pellets, sands and zeolites with two active ingredients, binders, friction reducer, dispersing agents and bentonite. Pellet-coated method showed similar floatability, collapsability and bio-efficacy to the commercial pellet-extruded one or better than that but unstable patterns of released concentration of chlomethoxyfen because of easy isolation of coated technical particles from the surface of granules. Sand-coated methods showed similar physical properties, released pattern of two active ingredients, and bio-efficacy to the commercial one. Liquid binders and/or dispersing agents are more important than powdered ones to control released concentration of active ingredients from the granule mixtures, to improve the floatability and dispersibility, and to show good bio-efficacy. Sand-coated one might be a suitable method if types and amount of liquid binders and dispersing agents are selected.

• Applied Biological Chemistry
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• v.29 no.1
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• pp.90-95
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• 1986

A comparative study of chemical characteristics, efficacy and relative merits of extruded and coated granules, containing fungicide and insecticide, was conducted under laboratory and field conditions. Probenzole (3-allyloxy-1,2-benzisothiazole 1,1-dioxide) and carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl methyl carbamate) were chosen as toxicants for rice blast(Pyricularia oryzae) and brown planthopper (Nilaparvata lugens) control, respectively. Stability of active ingredients in coated granule was superior to the extruded one under accelerated temperature. Active ingredient dissolution of coated one into distilled water showed slow release pattern. Pesticide residues in rice (Oryzae sativa, Chucheongbyeo) shoot applied with extruded one at the dosage of 3kg/10a retained higher levels than those with coated one on two days after application, while the residue levels were a reversed tendency on eight days after application. Efficacy on rice blast exhibited minute differences between the granules, on the other hand efficacy on brown planthopper by coated one was of higher rank than that by extruded one. Production cost of the combined pesticide granule by coating method could be cut down by 6% as compared to extrusion method.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.316-320
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• 1987

In order to determine effects of molinate mixture granular formulations on release rate and weed control efficacy of herbicides and growth of rice plants, zeolite impregnation, slurry, and sand-coating granules were tested in laboratory and greenhouse. Release rate of molinate and simetryn was faster in sand-coating granule than in zeolite impregnation and slurry type granules. Mixture granular formulations of molinate/simetryn or molinate/simetryn/MCPB showed good weed control efficacy and this trend was more remarkably shown in sand-coating granule. Sand-coating granule more inhibited growth of rice plants compared to zeolite impregnation and slurry type granules.

• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.101-105
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• 2015

Efficacy of novel nematicide, imicyafos GR was evaluated against two species of the root-knot nematodes in pot and greenhouse conditions. When tested in pots, the population of Meloidogyne incognita and M. hapla was reduced sixty days after treatment, with mortality rate of 91.5% and 90.6%, respectively. Suppression effect of imicyafos GR on root galling in tomato was tested. The number of root galls caused by M. incognita and M. hapla was reduced 60 days after nematode inoculation, with the efficacy of 94.2% and 95.1%, respectively. Under greenhouse conditions planted with watermelon, melon, cucumber, and tomato, the efficacy of imicyafos GR on M. incognita persisted up to 60 days after treatment, showing 90% of control efficacy. Moreover, the number of root galling was more reduced than fosthiazate treatment, with the potential as a control agent.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.2
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• pp.36-43
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• 2005

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.219-225
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• 2010

The solubility in water of granular pesticides is not equal because the difference of methods of producing a granular pesticide. This study was conducted to investigate fish acute toxicity of butachlor 5% GR, fipronil 0.4% GR by impregnation and carbosulfan 3% GR, diazinon 0.4% GR by coating, using carp (C. carpio), medaka (O. tatipes) and loach (M. anguillicaudatus). The test solution of each pesticide was prepared by direct addition of granular pesticide and add after grinding granular pesticide to powder in test water, We also investigated $LC_{50}$ and residual concentration until 96 hours. Test results were appeared that the treatment of powder was 1.2~4 time higher than granular and toxicity increased clearly according to elapsed time, And the residual amounts by time were detected much at early time in the powder treatment of butachlor GR and diazinon GR. Conclusively, fish acute toxicity and residual concentration in test solution appeared higher in the powder treatment than treat granular form directly in water. Also, 96 hours toxicity values were stable comparatively and the error is less than 48 hours.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.76-81
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• 1992

The technicals of KC-7079, isoprothiolane, perfluidone and tricyclazole were granulated with a mixture of inorganic carrier and oil-soluble binder, that is, stearly alcohol or ethyl cellulose. The concentration of the released active ingredient from the granules was analyzed at several days intervals after immersion of these granules in water at $25^{\circ}C$. At the content of stearyl alcohol less than $80g\;kg^{-1}$, the granule kneaded with stearyl alcohol mixture and water disintegrated in water. But the granule kneaded with methanol disintegrated in water at the content of stearyl alcohol less than $30g\;kg^{-1}$. The less the KC-7079-stearyl alcohol granule disintegrated, the slower the release rate of KC-7079 was. No matter how was increased the stearyl alcohol content, the release rate of KC-7079 granule which did not disintegrate was not significantly changed. The sustained releasing effect of the granules was little in the other three pesticides of which the water solubility was higher than of KC-7079(21 ppm). The granule made of ethyl cellulose did not disintegrate even at $5g\;kg^{-1}$ of ethyl cellulose. With the increase of ethyl cellulose content and the decrease of active ingredient in the granules, the sustaining effect of the granules on releasing acitive ingredient was increased. The lower the water solubility of pesticide was, the release rate tended to be sustained except perfluidone.

• The Korean Journal of Pesticide Science
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• v.17 no.3
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• pp.178-184
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• 2013

Residual toxicity test to honeybee was conducted to evaluate an indirect effects on honeybee after planting hole application of systemic insecticides which were highly toxic to honeybee (Apis mellifera). In this study, It was applied three application rates in the planting hole by three systemic insecticides, dinotefuran GR, imidacloprid GR and clothianidin GR at planting time of tomato. Residual analysis of foliage was carried out after periodic sampling the foliage and investigated the effects of exposed honeybee on the tomato foliage. The honeybee mortality by dinotefuran residues on the foliage was shown almost 100% at 7 days after treatment and decreased 17 days after treatment. The maximum mortality of honeybee by imidacloprid residues on the foliage was 44 ~ 72%. But the effect of pesticide lasted for 18 days and then decreased. The honeybee mortality by clothianidin residues on the foliage was 100% at 7 days after treatment and decreased 14 days after treatment. A tendency of the honeybee mortality and residue in foliage showed a similar character as time goes by. The residues in tomato foliage decreased gradually after 14 days by vigorous growth of tomatoes and the toxic effect of honeybee was significantly decreased after 21 days in actual usage of the treatment.

• Korean Journal of Environmental Agriculture
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• v.11 no.1
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• pp.1-8
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• 1992

New formulation of diazinon as granule preparing with piperonyl butoxide(PBO) and triphenyl phosphate(TPP) known as the inhibitor of monooxygenase(mo) and esterase was tested with the mortality of rice leaf hopper. Also, the mixed formulation of diazinon with tricyclazole, carbofuran and EPN were investigated about the residual pattern of diazinon in submerged soil condition at $30{\pm}2^{\circ}C$. Although the mortality about rice leaf hopper was higher only 10% on new formulation of diazinon than commercial at recommended dose but was 30-60% at half dose. Half life of diazinon in the formulation with 0.1% of PBO+TPP was 4.53 days in sterilized soil and 2.33 days in non-sterilized soil, and it was delayed about 0.74 and 0.45 respectively in contrast with the commercial granule. Also, half life of the new formulation with 1% PBO and PBO+TPP was delayed 0.44(PBO) and 0.65day(PBO+TPP) in non-sterilized soil condition, respectively. Half life of mixed formulation with tricyclazole, carbofuran, EPN or EPN+Carbofuran was delayed 2.61, 1.04, 0.43 or 2.7 days, respectively. As a result, the persistence rate of new formulation and mixed formulation was increased by inhibition of two enzymes affecting to the dgradation of diazinon in submerged soil.