• Weed & Turfgrass Science
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• v.6 no.4
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• pp.292-305
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• 2017

This paper provides the current status of weed science and prospects for the development of weed science based on the research trends presented at the 26th Asian Pacific Weed Science Conference in 2017. Approximately 458 researchers from 25 countries, including Korea, participated in the conference and presented 325 papers in 20 research areas. Major research topics were herbicide resistance, herbicide use, herbicide development, weed ecology, allelopathy, weed management, and exotic weeds. Particularly, there were many presentations and interesting to researchers about the development and use of new herbicides, such as florpyauxifen-benzyl ester, triafamone, fenquinotrione, and tolpyralate. Development of new herbicide formulations and spray methods were suggested as a solution for the population decline in rural area and low labor quality especially in Asia and Pacific regions. In future weedy rice and exotic weeds will be a serious problem in this area so we need to cooperate to make good technical and practical solutions.

• Life and Agrochemicals
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• s.272
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• pp.34-37
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• 2011

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.52-56
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• 2012

The occurrence of sulfonylurea-resistant weeds has recently increased in Korea. A survey was performed to investigate major paddy field weeds and frequently used herbicides in Gangwon province, Korea in order to establish a system to efficiently control herbicide-resistant weeds. The dominant paddy field weeds included Monochoria vaginalis (14%), Sagittaria trifolia (14%), Scirpus juncoides (13%), and Echinochloa spp. (13%), and the most widely used herbicides were oxadiazon 12% EC (27%), butachlor 5% GR (20%), oxadiargyl 1.7% EC (16%), and benzobicyclon+imazosulfuron+pyriminobac-methyl 6.1% SC (14%) in Gangwon province, Korea. Many paddy rice growers considered Scirpus juncoides, S. trifolia, Echinochloa spp. and M. vaginalis as herbicide-resistant weeds. An extensive research deserves to be conducted to monitor occurrence of herbicide-resistant paddy weeds in Gangwon province, Korea.

• Korean Journal of Weed Science
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• v.32 no.2
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• pp.133-138
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• 2012

This study was conducted to investigate the herbicidal activity against resistant biotype on sulfonylurea (SU) herbicides such as Scirpus juncoides and Monochoria vaginalis at the glasshouse and paddy rice cultivation area. In order to investigate resistance breakability against SU-resistanted annual weeds, new rice herbicides containing tefuryltrione [p-hydrophenyl pyruvate dioxygenase (HPPD) inhibitor] were tested. In both lab test and field experiment, tefuryltrione mixture, 4-HPPD inhibitor had shown excellent efficacy with a bleaching on the leaves of resistant annual weeds at early time after treatment and showed excellent persistance. Especially, tefuryltrione mixture had shown excellent controlling effect on annual and perennial SU-resistant S. juncoides in the regional field experiment. In phytotoxicity test, this tefuryltrione mixture had shown good selectivity to common rice species.

• Life and Agrochemicals
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• s.265
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• pp.30-33
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• 2011

• Agrochemical news magazine
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• v.16 no.1 s.124
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• pp.50-52
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• 1995

• Korean Journal of Weed Science
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• v.15 no.1
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• pp.1-12
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• 1995

These researches have been conducted to obtain the basic information of the effects of paraquat on plant species and to screen the plant species showing specific responses to paraquat. Paraquat resistance related to ecotype and overwintering capacity. Perennial and biennial species showed higher resistance than annual species. In a family, most species showed higher resistance were overwintering species. Lamiaceae, Brassicaceae, and Caryophyllaceae were tolerant to paraquat, whereas Poaceae and Asteraceae were sensitive. Especially Mosla dianthera of Lamiaceae, Hemistepta lyrata and Aster pilosus of Asteraceae, and Paspalum thunbergii of Poaceae showed higher tolerance than others. The response patterns of plant species on germination stage were different to those on vegetative stage. Germination of Amarathus lividus, Arabis glabra, and Bidens frondosa was not inhibited by paraquat. But their seedling growth were highly inhibited.

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.209-218
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• 2018

This study was carried out to investigate the occurrence and distribution of ALS inhibiting herbicide-resistant weeds and to estimate the appeared areas of resistant weeds in the paddy fields of Gyeongnam province of Korea in 2017 and 2018 using a soil assay method. Compared with the 2012 survey, this study showed that the infested ratio of ALS inhibiting herbicide-resistant weeds increased from 1.0% to 66.8% and the infested area increased from 876 ha to 49,008 ha. The infested area of ALS inhibiting herbicide-resistant weeds was estimated in Ulsan-si (8.4%), Hapcheon-gun (8.3%), Haman-gun (7.9%), Goseong-gun (7.9%), Hadong-gun (7.3%), Jinju-si (7.2%), Changnyeong-gun (7.0%), Gimhae-si (6.4%), Miryang-si (5.5%), Busan-si (4.9%), Uiryeong-gun (4.6%), Namhae-gun (4.3%), Geochang-gun (4.2%), Changwon-si (3.8%), Geoje-si (2.9%), Yangsan-si (1.8%), Sancheong-gun (0.9%) and Tongyeong-si (0.4%), and the herbicide resistant weeds was not occurred in Hamyang-gun. The most dominant ALS inhibiting herbicide-resistant weeds in paddy fields were Monochoria vaginalis, followed by Echinochloa oryzicola, Lindernia dubia, Scirpus juncoides, Ludwigia prostrata, Cyperus difformis, Sagittaria trifolia and Rotala indica. ALS inhibiting herbicide-resistant M. vaginalis, L. dubia, and E. oryzoides occurred throughout Gyeongnam province, and ALS inhibiting herbicide-resistant S. trifolia and R. indica were only found in Gimhae-si. Therefore, these results will be utilized to estimate population dynamics of ALS inhibiting herbicide-resistant weeds and provide proper management practices in the paddy fields of Gyeongnam province.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.268-279
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• 1998

• Weed & Turfgrass Science
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• v.7 no.3
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• pp.181-190
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• 2018

This study was conducted to investigate the occurrence of an acetolactate synthase (ALS) inhibiting herbicide resistant weed on paddy at 289 sites by soil sampling in Chungcheongbuk-Do of Republic of Korea from February to April in 2017. The most dominant weed was Monochoria vaginalis and Echinochloa oryzicola on each city and county. ALS inhibiting herbicide resistant ratio and occurrence area were 80.6% and 28,272 ha, respectively, in Chungcheongbuk-Do which was 3 times than in 5 years ago. The herbicide resistant ratio, Okcheon-Gun was the highest at 93.8%, Chungju-Si, Boeun-Gun, Yeongdong-Gun, Jincheon-Gun and Geosan-Gun were over 80%, Cheongju-Si, Eumseong-Gun and Jeungpyeong-Gun were over 70%. The herbicide resistant area, Cheongju-Si had the largest at 6,957 ha, Chungju-Si was 4,277 ha, Jincheon-Gun and Boeun-Gun was 3,536 ha and 3,282 ha, respectively. By weed, ALS inhibiting herbicide resistant ratio and occurrence area, Monochoria vaginalis was 49%, 17,646 ha, Echinochloa oryzicola 44%, 15,617 ha, Schoenoplectiella juncoides 29%, 10,377 ha, respectively. In all cities and counties of Chungcheongbuk-Do, Monochoria vaginalis and Echinochloa oryzicola are more than 40% resistant to ALS inhibiting herbicides, intensive management is required. The use of sulfonylurea herbicides is increasing, most farmers use herbicides 10 days after transplanting, so management after transplanting is necessary and the occurrence of herbicide resistant weeds should be reduced by alternating herbicide application every year.