• The Korean Journal of Pesticide Science
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• v.3 no.3
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• pp.1-5
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• 1999

Novel O-quinolinylamidoxime derivatives were prepared by replacement of the carboxylic group at the 8 position of quinclorac with various amidoximes. In the flooded paddy conditions, most of the compounds show good herbicidal activity at a rate of 1 kg/ha. Some of them showed excellent herbicidal activity at a rate of 60 g/ha against barnyardgrass (Echinochloa aryicola) with good selectivity on rice. Under the two-leaf stage of barnyardgrass, most of O-quinolinylamidoximes showed good herbicidal activity, expecially compound 3c which showed excellent herbicidal activity barnyardgrass at a rate of 125 g/ha with good rice seletivity.

• Journal of Environmental Science International
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• v.14 no.4
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• pp.445-449
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• 2005

A simple and sensitive analytical method based on RP-HPLC with UV detector$(225{\cal}nm)$ and mobile phases using $0.1{\%}$ phosphoric acid and acetonitrile was developed for simultaneous determination of quinclorac, bentazone, 2,4-D, bensulfuron-methyl, dymuron, capropamide, pencycuron, ethofenprox. This method was resulted in recovery of $78{\~}96{\%}$ with RSD $3.3{\~}7.5{\%}$, LODs $0.12{\~}0.84$ and LOQs $0.34{\~}1.20{\cal}mg/L$. Calibration curves were linear with r of $0.9995{\~}0.9999$.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.124-131
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• 1992

Not only reducing the carry-over effects of quinclorac [3, 7-dichloro-8-quinoline carboxylic acid] used in paddy field to some following vegetable crops but also rationalizing agro-ecology conservation and farm economy, the reducing feasibility of application rates by various cropping patterns and application timing after rice seeding and transplanting. Four cropping patterns namely dry direct seeding(DDS), flooded direct seed(FDS), transplanting of 8 days old early seedlings(EST) and 25 days old machinery seedling(MST) were experimented with 7 application timings as 0, 5, 10, 15, 20, 25, 30 days after seeding/transplanting and 9 levels of application rates as 0, 75, 150, 225, 300, 375, 450, 525, and 600g ai/ha of the chemical, respectively. Within the maximum permitted limit of rice phytotoxicity, the minimum application rate of quinclorac to complete control of Echinochloa crus-galli as influenced by various cropping patterns with application timing could be evaluated as follows : A. Dry direct seeding : The minimized application rate at application timing upto 10 days after seeding (DAS) was counted 150g ai/ha, and delaying upto 15-30 DAS, the rates were increased upto 225-525g ai/ha. B. Flooded direct seeding and transplanting : The application rates were minimized 75g ai/ha at application timing upto 10 days after seeding/transplanting(DAS/T), 150g ai/haupto 15 DAS/T, and 225g ai/ha at later than 20 DAS/T, respectively.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.279-286
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• 2002

To improve the growth inhibition activities and selectivities for quinclorac family, novel 3-substituted phenyl-5-(3,7-dichloro-8-quinolinyl)-1,2,4-oxadiazole derivatives as the substrate were synthesized and their the activities ($pI_{50}$) against shoot and root of rice plant (Oryza sativa L.) and barn-yard grass (Echinochloa crus-galli) were measured. And the quantitative structure-activity relationships (QSARs) between physicochemical parameters of the substitutents (R) on phenyl group and the activities ($pI_{50}$) were analyzed quantitatively. According to the SAR analyses, the substrates of planar conformation showed higher herbicidal activities against barnyard grass than rice plant. The activities against rice plant depend on the electronic effect (shoots: ${\sigma}_{opt.}=0.49$ & root: $R_{opt.}=-0.15$) of substituents, whereas the activities against shoots and roots of barnyard grass depend on hydrophobicity (${\pi}_{opt.}=0.37{\sim}2.40$). There were conditions of selective growth inhibition activity against barnyard grass when such a ortho-substituted electron donating substituents showing the hydrophobicity value, ${\pi}=2.40$ were introduced on the phenyl ring. The 2-tolyl substituent predicted from SAR equations was expected to have better growth inhibition activity and selectivity (${\Delta}pI_{50}=1.26$) for barnyard grass.

• Korean Journal of Weed Science
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• v.10 no.4
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• pp.255-260
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• 1990

Seventeen different herbicides were screened to select promising ones for the control of weeds, which may be used in paddy fields transplanted with 8 days old young rice seedlings. Four classes of herbicides were chosen and tested with seedlings grown under different cultivating conditions. Contact herbicides such as diphenyl-ether and oxadiazol showed severe growth retardation of rice seedlings. Carbamate class(dimepiperate), quinoline class (quinclorac), pyrazol class(pyrazolate), acid amide class(mefenacet and pretilachlor), addition of safener (pretilachlor+fenclorim and mefenacet+bensulfuron+dymuron) and unknown class (KC-7079) exhibited normal growth of seedlings. Sulfonyl urea herbicide class(cimosulfuron, bensulfuron, pyrazosulfuron), and oxarane class(tridiphane) showed the slight growth inhibition but recovered shortly.

• Korean Journal of Environmental Agriculture
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• v.13 no.1
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• pp.60-65
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• 1994

Absorption and translocation of bensulfuron-methyl {methyl 2[[[[[(4,6-dimethoxy-2-pyrimidinyl) amino]carbonyl]amino]sulfonyl]methyl]benzoate} in rice (Oryza sativa L.) as affected by mineral nutrients and mixed herbicides were determined using the $^{14}C-labeled$ herbicide in culture solution. Absorption of $^{14}C-bensulfuron-methyl$ by the root decreased with increasing concentration of bensulfuron-methyl. However, increase in the application concentration did not affect movement of the $^{14}C$ to the shoot. There was no difference in total amount of $^{14}C-bensulfuron-methyl$ taken up between absorption periods of 12 and 48 hours, whereas $^{14}C-bensulfuron-methyl$ translocated to the shoot increased with increasing the absorption period. When bensulfuron-methyl mixtures were applied, butachlor [N-(butoxymethyl)-2-chloro-N-(2',6'-diethylphenyl)acetamide] did not affect absorption and translocation of $^{14}C-bensulfuron-methyl$. However, quinclorac (3,7-dichloro-8-quinoline carboxylic acid) mixed at a high concentration resulted in decrease in absorption and translocation of $^{14}C-bensulfuron-methyl$. Nutritional disorder such as deficient or excess supply of mineral nutrients caused to inhibit absorption of $^{14}C-bensulfuron-methyl$. The greatest decrease and delay of $^{14}C-bensulfuron-methyl$ absorption and/or translocation occurred in N-deficient and S-excess supply conditions.

• Korean Journal of Plant Tissue Culture
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• v.26 no.3
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• pp.183-187
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• 1999

To establish an efficient screening system for new herbicides using plant cultured cells, responses of tobacco photomixotrophic cultured (PH) cells to various herbicides with different modes of action were surveyed by measuring the cell growth and ion conductivity in medium. The cells were cultured in Murashige and Skoog (MS) medium containing 0.7mg/L 2,4-D, 0.3mg/L kinetin and 30 g/L sucrose at $25^{\circ}C$ in the light (100 rpm). Chemicals were treated to suspension cultures of tobacco PH cells at the time of subculture. The cell growth and ion conductivity in the medium were investigated on 12 days after chemical treatment. The ion conductivity assay gave well correlated results to the cell growth inhibition data. The responses of tobacco PM cells were dependent on the modes of action of chemicals tested. Atrazine, an inhibitor of photosynthetic electron transport (PET), strongly inhibited both the cell membrane and cell growth ($IC_{50}$/, about 1 $\mu$M). Butachlor (an inhibitor of cell division), glufosinate (an inhibitor of amino acid biosynthesis), and fluridone (an inhibitor of carotenoid biosynthesis) showed a dose-dependent inhibition. However, Quinclorac, a herbicide with an auxin activity, did not affect the cell growth and ion leakage. These results suggested that tobacco PM cells is suitable materials for the simple screening of new herbicides such as PET, amino acid biosynthesis, ceil division inhibitors by measuring the cell growth and ion conductivity.

• Journal of Applied Biological Chemistry
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• v.62 no.3
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• pp.219-228
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• 2019

This study summarized processing factor (PF) by the stage of rice and barley processing based on JMPR reports from 2006 to 2016. We compared PF of 17 pesticides in rice products during the processing of rice grain, husked rice, polished rice, hulls, bran and cooked rice. Among the 17 pesticides, 12 pesticides except for 5 pesticides such as acephate, methamidophos, glufosinate, quinclorac and sulfoxaflor mostly decreased in pesticides when rice grain processed into brown rice. Pesticides tended to be partially reduced when processed from husked rice to polished rice. However, hulls and bran produced during the milling process were concentrated. Acephate and others, 5 pesticides are systemic pesticides, and pesticides are penetrated into foods, and a large amount of pesticides was not removed during the milling process. The remaining pesticide residues in polished rice were mostly removed after processing into cooked rice, and trace amounts of pesticide residues remained. In the comparison of 23 pesticides PF during the processing of barley products (pearl barley, flour, short, malt, beer, hulls and bran). Most of the pesticide except for 4 pesticide (ethephon, pyraclostrobin, penthiopyrad, sulfoxaflor), which are systemic pesticides, decreased during the process of pearl barley production out of the barley grain. The pesticide in the malt, which was made by steeping pearl barley was concentrated but when processed into beer, pesticide was remained only in trace amounts.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.90-97
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• 1987

An attempt was done at the Yeongnam Crop Experiment Station in 1986-'87 to obtain herbicide tolerant variant through cell culture. Immatured rice grain was more rapidly and efficiently formed callus in dehulled rice culture method for both rice cultivar types, Tongil type (Indica/Japonica) and Japonica-type. However, Japonica-type cultivar was generally superior than Tongil-type Cultivar in callus formation. Expression rate of herbicide tolerant variant varied depending upon rice cultivar, plant species and herbicide properties. In case of Nagdongbyeo (Japonica) at the first subculture, 46.3% of total callus pieces appeared as herbicide tolerant variant in herbicide media of CGA142464 and followed by NC-311 (11.6%), Butachlor (7.5%), 2.4-D (2.1%), Quinclorac (0.89%), and Propanil (0.25%), in order. This degree of appearance of herbicide tolerant variants rapidly increased as passage of subculture was advanced. Herbicide tolerant callus hardly regenerated as normal plant even though large variations exhibited among culture media.

• Korean Journal of Weed Science
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• v.16 no.4
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• pp.282-291
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• 1996

This experiment was conducted to investigate the phytotoxicity of several herbicides for rice and weed control with herbicides application times and seeding times in flooded direct-seeded rice field. The phytotoxicity of herbieides(bensulfuron methyl+dimepiperate, bensulfuron methyl+mefenacet+dymron, bensulfuron methyl+quinclorac, pyrazosulfuron-ethyl+molinate, pyrazosulfuron-ethyl+thiobencarb, pyrazosulfuron-ethyl+cyhalofop, imazosulfuron+molinate, imazosul-furon+cyhalofop) for rice in different seeding dates was the most high at 7 days after seeding(DAS) Followed by 12 and 17 DAS. In particular, the bensulfuron methyl+mefenacet+dymron showed very high phytotoxicity to rice plants. Weed species occurred in direct-seeding field seeded on May 1 were 10 species (grasses ; 1, broad-leaves ; 6, sedges ; 3) and Echinochloa crus-galli was the most dominant weed among them. Whereas weed species occurred rice field seeded on May 22 were 7 species(grasses ; 1, broad-leaves : 3, ridges ; 3) and Echirochloa crus-galli was the most dominant weed among them. The weed control for annual weeds(Echinochloa crus-galli, Aneilema keisak, and so on) and perennial weeds(Cyperus serotinus, Scipurus juncoides) was remarkably effective at the application of 7 and 12 DAS, but it of Eleocharis kuroguwai was effective at the application of 17 DAS on two seeding times. The yields were decreased significantly at the plot affected severely by herbicides applied at 7 DAS and the plots showed low efficacy at herbicides application of 17 DAS.