• Korean Journal of Weed Science
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• v.3 no.2
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• pp.199-207
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• 1983

To select appropriate herbicides for adzukibean and mungbean, a series of experiments was carried out in both field and pot from 1980 to 1983. Tolerance to the herbicides tested was highest in soybeans and followed by mungbean and adzukibean in the order. Pre-emergence herbicides showed relatively low phytotoxicity were chlorambem, linuron, and metribuzin for adzukibean and alachlor and butachlor for mungbean. Post-emergence herbicides showed no external phytotoxicity for adzukibean and mungbean were alloxydim, Dowco 453, fluazifop, etc.. For mungbean, terbutryn (1.5 kg, a.i./ha) which is pre-emergence herbicide showed the best weeding control efficacy but some possible phytotoxicity. Among post-emergence herbicides, acifluorfen (300 g, a.i./ha) showed the best weeding efficacy with no yield reduction though some phytotoxicity which recovered within 20 days. Compared to single herbicide application, the mixture or systemic treatments of herbicides showed much higher weeding control efficacy and seed yields: the systemic treatments of linuron (500 g, a.i./ha) / Dowco 453 (180 g, a.i./ha) or linuron (500 g, a.i./ha) / fluazufop (260 g, a.i./ha) for adzukibean and the mixture treatment of alachlor (1.31 kg, a.i./ha) / acifluorfen (150 g, a.i./ha) for mungbean, respectively.

• Korean Journal of Weed Science
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• v.31 no.4
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• pp.375-383
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• 2011

This experiment was carried out to confirm characteristics of macro granule (GG) for herbicidal efficacy by using remote-controlled aerial application (RCAA) to control annual and perennial weeds in rice paddy field, and phytotoxicity to rice and non target plants of formulation types. Herbicidal efficacy of GG applied by using RCAA was 93.6~96.6% in flooded direct sowing cultivation. There was no difference in phytotoxicity between the hand and the power applicator methods in terms of height, number of tiller and yield component. Herbicidal efficacy of GG applied by using RCAA was 92.7~97.3% in machine transplanting rice field. There was no difference in phytotoxicity between the hand and RCAA methods in terms of height, number of tiller and yield component. When suspension concentrate (SC) and GG were applied directly on Chinese cabbage, lettuce, cucumber, pepper, soybean and wild sesame, several symptoms of injury such as, the inhibition of growth, yellowish, leaf fall and withering was observed.

• Korean Journal of Weed Science
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• v.31 no.4
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• pp.384-393
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• 2011

Sulfonylurea herbicide-resistant weeds are spreading widely and distributed about 106,951 hectare in paddy rice fields in Korea. Morever all biotype of Scirpus juncoides which were collected at 69 spots all over paddy rice fields in 2008 were identified biotype of sulfonylurea herbicide-resistant. Benzobicyclon is a p-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor, which is absorbed through root and basal stem of weeds so cause bleaching of newly developing leaves. Benzobicyclon was very effective to control Scirpus juncoides, Monochoria vaginalis, sedges and broadleaves weeds, so it have been developed various formulation like a suspension concentrate (SC), a water dispersible granule (WG), a granule (GR) and a DT (tablet for Direct application). During recently 6 years, benzobicyclon-mixtures herbicides have been registered over than 54 products in paddy fields. Herbicidal efficacy by formulations of benzobicyclon and its mixture herbicides were highest in DT, followed by SC and GR. Herbicidal efficacy of the kaolin and $CaCO_3$ carrier of GR was better and stable than that of talc and bentonite carrier. Growth and yield of rice were not affected much by formulations, application rates and rice cultivation methods.

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.57-69
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• 2012

This study was conducted to find the effective management of main weeds including herbicide-resistant Echinochloa oryzicola, Scirpus juncoides and Monochoria vaginalis in direct seeded rice on puddled paddy surface. The dominant dominances in direct seeded rice on puddled paddy surface were increased for three years between 2009-2011. In weed distribution in 2011, the occurrence density of S. juncoides decreased greatly, but it of E. oryzicola increased especially as compared with it of 2009. Benzobicyclon, mesotrione and pyrimisulfan were effective to sulfonylurea(SU)-resistant S. juncoides and M. vaginalis at 5 and 12 days after seeding, however, the efficacy of bromobutide to sulfonylurea-resistant M. vaginalis was decreased slightly at 12 days after seeding. And carfentrazon and pyrazolate were ineffective to S. juncoides. In direct seeded rice on puddled paddy surface which ACCase and ALS inhibitor-resistant E. oryzicola was not occurred, benzobicyclon+penoxsulam+pyrazosulfuron-ethyl ET, bromobutide+imazosulfuron+metamifop GR, and flucetosulfuron+mesotrione+pretilachlor GR showed the control effect over 94% to main weeds included sulfonylurea-resistant S. juncoides and M. vaginalis. The E. oryzicola dominating in direct seeded rice on puddled paddy surface were not any affected to the survival by treatment with recommended doses of cyhalofop-butyl and penoxsulam tested. The ACCase and ALS inhibitor-resistant E. oryzicola was effectively controlled by mefenacet and fentrazamide up to the 2nd leaf stage. In direct seeded rice on puddled paddy surface domiating coincidentally by herbicide-resistant E. oryzicola, S. juncoides and M. vaginalis, "one-shot herbicide" included with mefenacet, fentrazamide, penoxsulam and metamifop could't be used because of low control effect or rice injury. The sequential treatment of benzobicyclon+thiobencarb SE and bensulfuron+mefenacet+thiobencarb GR controlled effectively the herbicide-resistant E. oryzicola, S. juncoides and M. vaginalis in direct seeded rice on puddled paddy surface. The days required by the 3rd leaf stage of herbicide-resistant E. oryzicola, S. juncoides and M. vaginalis in direct seeded rice on puddled paddy surface seeded in May 20 shortened by 4 days as compared with it of June 10.

• The Korean Journal of Pesticide Science
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• v.5 no.3
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• pp.41-46
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• 2001

This study was conducted to develop a high throughput system for screening acetolactate synthase(ALS) inhibitors, and to detect basic mother molecules for developing new novel herbicide candidates. The high throughput screening (HTS) method using 96-well plate and microplate reader was developed. This method is 8 times more effective than basic technique in one cycle per person. Futhermore, considering for less than 1/10 volume of materials required for ALS test and enzyme kinetics with 16 times faster speed compared to those of former procedure, this HTS method has more than 100 times higher efficacy than basic system in a consecutive procedure. We discovered 11 new ALS inhibitors such as 2-oxoglutaric acid, aminooxyacetic acid, azelaic acid, citric acid, cyanuric fluoride, itaconic acid, malonic acid, niclosamide, oxalic acid, glyoxylic acid, and suramin from 107 commercial plant-specific inhibitors using this technique. We hope these results might be useful to discover lead compounds for developing new novel herbicide candidate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.738-746
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• 1995

Greenhouse studies were carried out to find the difference of growth, weed competition and herbicides response in barley(Hordeum vulgare L. emend Larnark) under foggy and non-foggy condition. Plant height, leaf stage, leaf width and shoot fresh weight of barley under foggy condition were greatly increased, while heading rate ripening rate and number of grains per panicle of barley were reduced. Weed emergence based on fresh weight was much greater under foggy than that under non-foggy condition. Plant height of barley under foggy condition was increased comparing with non-foggy condition and significantly reduced with increasing the duration of weed competition, while 1,000-grain weight of barley reduced by the early competition(0∼20 days). Among the herbicides treated, butachlor and thiobencarb inhibited growth of barley under foggy than non-foggy condition. Plant height of barley treated of herbicides under foggy condition was ever increased but 1,000-grain weight of barley was reduced. Weeding efficacy(75-90%) by shoot fresh weight of weeds under foggy condition at 25 days after application was lower 3 to 15% than that under non-foggy condition.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.175-186
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• 1985

Research situation and recent research activities of the RDA of Korea were reviewed and summarized for rice nurserybed. Sixty five percent of total 784 weed research items were carried out as rice research while only 6 percent was belonged to nurserybed within rice research. The floristic composition based on the degree of dominance significantly affected by herbicide properties, type of nurserybed and seeding itself. Herbicidal phytotoxicity of currently used several herbicides was greatly dependent upon the covering, absorption, germination, and irrigation regimes. The new safening agent "CGA 123 407" (4,6-dichloro-2-phenyl-pyrimidine) permited the safe application of pretilachlor (2-chloro-2',6-diethyl-N-(2-propoxyethyl) acetanilide) as a pre-emergence herbicide without reducing herbicidal efficacy. Several new herbicides, pyrazolate (4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yl-p-toluenesulphonate), SL-49 (1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-phenacyloxy-pyrazole) MY-93 (S(1-methyl-1-phenethyl)-piperidine-1-carbathioate) and DPX-84 ((methyl 2- ((4,6-dimethoxypyrimidin-2-yl) amino-carbonyl) aminosulfonylmethyl)) benzolate)) performed satisfactorily in terms of safety and herbicidal efficacy for both surface covered and surface pressed nurserybed after herbicide application and thus expected very significant contributions not only for all kind of nurserybeds but also for direct seeding.

• Korean Journal of Weed Science
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• v.7 no.2
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• pp.208-219
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• 1987

Newly developed several herbicides were evaluated as paddy rice herbicide at the Yeongnam Crop Experiment in 1986. And also, the general situation of rice cultivation between Korea and Japan was compared. Twenty-nine herbicides of the total 59 herbicides were used as paddy rice field in Korea while these were 100 and 187, respectively, in Japan. Among paddy rice herbicides, butachlor was the most important herbicide in both countries. However, the degree of concentration to a particular herbicide was greater in Korea compared to Japan; consumption rate of single butachlor to the total herbicide were 66.5% for Korea and 11.9%r for Japan, respectively. Pyrazolate, pyrazoxyfen and quinclorac were the most promising hebicides in pressed-type rice nurserybed in terms of herbicidal efficacy and phytotoxic effect. For transplanted paddy rice field, single application of NC-311 or combining applications of NC-311 with butachlor or quinclorac gave excellent results at the weed community that was dominated by Echinochloa crus-galli, Aneilema japonica, Ludwigia prostrata, Scirpus hotarui, Cyperus serotinus, Potamogeton distinctus and Eleocharis kuroguwai. Particularly the above combining applications maintained their excellent herbicidal effect up to 3 leaf stage of E. crus-galli without arising herbicidal phytotoxicity. Pyrazolate and three sulfonyl urea herbicides (DPX-5384, NC-311 and CGA 142464) exhibited very high safety against rice. However, Japonica type rice cultivar was a little bit more sensitive than Indica/Japonica type rice cultivar. On the other hand, the effect of these herbicides against E. crus-galli was very strong. Herbicidal effect against E. crus-galli was enhanced through shoot absorption for sulfonyl urea herbicides and root abosorption for pyrazolate and quinclorac, respectively.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.203-211
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• 2017

This study was conducted to investigate the phytotoxicity of main rice varieties and control efficacy of HPPD inhibitor to major paddy weeds at the time of temperature rise due to climate change. Phytotoxicity of herbicide to rice was increased as temperature was increased, and more severe in root than shoot. The phytotoxicity of japonica rice cultivars for the rice were mild enough to recover. However, glutinous rice, super high yield rice, and Tongil rice varieties were damaged enough to decrease the yield. Shindongjinbyeo transplanted by June 15, showed phytotoxicity enough to recover. However, in the rice field on June 30 and on July 15, the rice showed a remarkable inhibition. The control effect of Monochoria vaginalis and Scirpus juncoides was more than 90% under the temperature condition controlled artificially. However, Echinochloa oryzicola was controlled 40% at $27.5^{\circ}C$, which is a high temperature condition. In rice fields with different transplanting times, annual weeds except for E. oryzicola were highly controlled by 90% or more regardless of the time of transplanting.

• Korean Journal of Weed Science
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• v.17 no.4
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• pp.368-374
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• 1997

Investigated ware the decomposition of mulch paper, weed occurrence, and rice growth and yield in transplanting rice culture with paper mulching in 1996 and 1997. The mulch paper were developed from domestic old corrugated container. In the experiment of 1996 where 25 percent of nitrogen fertilizer was applied as tillering fertilizer at 15 days after transplanting, it took about 28 to 40 days for the mulch paper to reach 50 percent decomposition according to types of mulch paper and fertilizer amount. The decomposition was faster in 18kg N/10a fertilization plot than in 12kg N/10a fertilization plot, and slower in the mulch paper treated with polyamidepolyamine epichlorohydrin resin(PPE) for the reinforcement of wet strength than in the mulch paper without PPE. In the experiment of 1997 where nitrogen fertilizer was not applied at tillering stage and instead 70 percent of nitrogen fertilizer was supplied as basal fertilizer, it took more than 42 days for the mulch paper(PPF treated) to reach 50 percent decomposition. Paper mulching was found to be very effective in controlling the paddy weeds at early stage of rice growth, but the efficacy, of weed control decreased especially in the mulch paper without PPE at later stage of rite growth due to the occurrence of Ludwigia prostrata in 1996. Few weeds occurred even in non-mulched plot without herbicide in 1997, rending difficulties in evaluating the efficacy of mulch paper in weed control, However, it could be deduced from the durability of mulch paper that paper mulching would have had sufficient efficacy of weed control. Rice yield was only 185kg/10a in the plot without mulching and weed control, but 657kg/10a and 771kg/10a in the paper(PPE treated) mulching plot with 12kgN/10a and 18kgN/10a, respectively, in 1996. The paper mulching plot showed rice yield similar to the weed control plot with herbicide in 1997. It would be concluded that paper mulching could ensure effective weed control and as high yield as the conventional rice cultivation with herbicidal weed control if the corresponding amount of basal nitrogen fertilizer is increased instead of omitting the nitrogen fertilizer at tillering stage.