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: Sulfonylurea (SU)-resistant weeds of eight annual weeds, Monochoria vaginalis, Scirpus juncoides and Cyperus difformis, etc., and four perennial weeds, Scirpus planiculmis, Sagittaria pigmaea, Eleocharis acicularis and Sagittaria trifolia as of 2013 since identification Monochoria korsakowii in the reclaimed rice field in 1998. And the resistant Echinochloa oryzoides to ACCase and ALS inhibitors has been confirmed in rice fields of the southern province, Korea in 2009. In the beginning, the M. vaginalis, S. juncoides and C. difformis of these SU-resistant weeds were rapidly and individually spreaded in different fields, however, these resistant weeds have been occurring simultaneously in the same filed recently. The resistant biotype by weed species demonstrated about 10-to 1,000-fold resistance, based on GR50 values of the SU herbicides tested. And the resistant biotype of E. oryzoides to cyhalofop-butyl, pyriminobac-methyl, and penoxsulam was about 14, 8, and 11 times more resistant than the susceptible biotype base on GR50 values. The products and applied area of SU-included herbicides have been increased rapidly, and have accounted for about 69% and 96% in Korea, respectively. In Korea, the main cause of SU-resistant weed is extensive use of these herbicides. The top ten herbicides by applied area were composed of all SU-included herbicides by 2003. The concentrated and successive treatment of ACCase and ALS inhibitors for control of barnyardgrass in rice led up to the resistance of E. oryzoides. Also, SU-herbicides like pyrazosulfuron-ethyl and imazosulfuron which effective to barnyardgrass can be bound up with the resistance of E. oryzoides. The ALS activity isolated from the resistant biotype of M. korsakowii to SU-herbicides tested was less sensitive than that of susceptible biotype. The concentration of herbicide required for 50% inhibition of ALS activity (I50) of the SU-resistant M. korsakowii was 14-to 76-fold higher as compared to the susceptible biotype. No differences were observed in the rates of [ 14 C]bensulfuron uptake and translocation. Acetolactate synthase (ALS) genes from M.vaginalis resistant and susceptible biotypes against SU-herbicides revealed a single amino acid substitution of proline (CCT), at 197th position based on the M. korsakowii ALS sequence numbering, to serin (TCT) in conserved domain A of the gene. Carfentrazone-ethyl and pyrazolate were used mainly to control SU-resistant M. vaginalis by 2006 in Korea. However, the alternative herbicides such as benzobicyclone, to be possible to control simultaneously the several resistant weeds, have been developing and using broadly, because the several resistant weeds have been occurring simultaneously in the same fieled. The top ten herbicides by applied area in Korea have been occupied by products of 3-way mixture type including herbicides with alternative mode of action for the herbicide resistant weeds. Mefenacet, fentrazamide and cafenstrole had excellent controlling effects on the ACCase and ALS inhibitors resistant wh...

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: This study was conducted to evaluate the efficacy of herbicide in winter cereal crops, barley and wheat. The efficacy of soil-applied herbicides, linuron EC and pendimethalin, thiobencarb GR was greater than that of butachlor EC. Linuron EC controlled average 95% and pendimethalin, thiobencarb GR controlled average 97% within 150 days after soil-applied treatment. When compared with untreated control, no visual injuries were detected at single and double dosage of linuron EC and pendimethalin, thiobencarb GR. The yield of barley increased in linuron EC and wheat increased in pendimethalin, thiobencarb GR treatments when compared with butachlor EC. The efficacy of foliage treatment, bentazone+propanil ME was greater than that of bentazone SL. Bentazone+propanil ME controlled average 96% in barley and 97% in wheat, within 30 days after foliage treatment. When compared with untreated control, no visual injuries were detected at single and double dosage of bentazone+propanil ME. The yield of barley and wheat increased in bentazone+propanil ME treatments when compared with bentazone SL. Based on these data, combinations of these herbicides could be applied to provide effective weed management in barley and wheat field.Key words : Bentazone, Propanil, Linuron, Pendimethalin, Thiobencarb, Weed control *Corresponding author: Tel: +82-02-580-3600 E-mail address: kskang@dbagro.co.kr † These authors contributed equally to this work.

: This study was conducted to evaluate the efficacy of benzobicyclon mixtures by using Remote-controlled aerial application (RCAA) to control annual and perennial weeds in rice paddy field. Eight annual weed species including Echinochloa crus-galli L. and three perennial weeds were dominated in the experimental field. Application of benzobicyclon mixtures using RCAA was highly effective to control both annual and perennial weed species. When compared with untreated control, no visual injuries were detected at single and double dosage of benzobicyclon mixtures. Finally, rice yield in the benzobicyclon mixtures was as much as that in the hand weeding. This study indicates that benzobicyclon mixtures using RCAA can be applied to control both annual and perennial weed species in rice paddy field.