• Title/Summary/Keyword: Weed Science

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A Survey of Weeds Occurrence on Paddy Fields in Gyeongbuk Province in Korea (경북지역 논 잡초 발생분포 조사)

  • Kim, Sang Kuk;Kim, Hak Yoon
    • Weed & Turfgrass Science
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    • v.3 no.1
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    • pp.6-12
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    • 2014
  • The survey of weed occurrence was conducted to identify problem weed species in the paddy field. The 320 sites of the 13 regions in Gyeongbuk Province were investigated from June to July, 2013. In the whole region, 51 weed species were identified including 34 annuals and 17 perennials. The highest importance value of annual weed and perennial was dominant 88.4 and 48.7%, in Gumi region, respectively. The most dominant weed species in paddy fields of Gyeongbuk Province were Monochoria vaginalis var. plantaginea (10.80%), followed by Lemna paucicostata (10.74%), Bidens tripartite (8.77%), Echinochloa oryzoides (7.17%), and Scirpus juncoides (6.20%). The similarity of paddy weeds in 13 regions observed through TWINSPAN analysis was distinguished by Ludwigia prostrata, Scirpus juncoides, Lindernia dubia, Polygonum aviculare, and Alopecurus aequalis var. amurensis. The weed species, Ludwigia prostrata, was divided into the four regions, Gyeongju, Gumi(direct seeding cultivation), Youngcheon and Euiseong and ten regions, Gumi, Bonghwa, Sanju, Goryung, Youngdeog, Pohang, Sanju, Andong, Yecheon, and Cheongdo.

Weed Occurrence and Control at Soybean Culture in Rice-Soybean Rotated Paddy Field (답전윤환(畓田輪換) 콩 재배지(栽培地)에서의 잡초발생(雜草發生) 및 방제(防除))

  • Kim, K.U.;Shin, D.H.;Park, S.J.;Jeong, J.W.;Hwang, S.S.
    • Korean Journal of Weed Science
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    • v.15 no.4
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    • pp.313-320
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    • 1995
  • The major weeds observed in soybean(Glycine max(L.) Merr.) culture at the paddy field where transplanted rice was cultivated in previous year were Digitaria spp., Echinochloa spp., Chenopodium ficifolium, Rorippa islandica and Stellaria alsine. C. ficifolium and R. islandica increased as soybean was cultivated for two years in the same field. Weed biomass decreased by 84.8% as the seeding date was delayed from April 26 to May 20. Most of weeds started to emerge from 20 days after seeding(DAS) until 40 DAS, and higher seed yield was obtained by eliminating the weeds emerged until 40 DAS. The development of soybean branches, pods stem diameter was severely injured by weed interference, and thus soybean seed yield was reduced by 70% in comparison with a full season weed free plot. Herbicides such as pendimethalin, metolachlor, metolachlor+prometryn and alachlor controlled very effectively weeds present in soybean culture in rice-soybean rotated paddy field.

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