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Volume 48 (2003)
- Issue 4 Pages 211-
- Issue 3 Pages 109-
- Issue 1-2 Pages 1-
- Issue Supplement Page･･･
Volume 48, Issue 1-2
Displaying 1-8 of 8 articles from this issue
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Hiroshi Kohara, Hiroaki Watanabe, Kazuyuki Itoh2003 Volume 48 Issue 1-2 Pages 1-8
Published: May 31, 2003
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSThree experiments were conducted to investigate the seed viability of Scirpus juncoides Roxb. var. ohwianus T. Koyama in both undisturbed and disturbed conditions.
In 1997, plants of S. juncoides were sampled from rice fields in the Hokkaido region. The samples included three sulfonylurea-resistant populations and one susceptible population.
In Experiment 1, seeds from the sampled plants were buried 15 to 20cm deep in the undisturbed lower soil layer of a rice field. In Experiment 2, the seeds were incorporated in the upper soil layer (0 to 15cm) that was disturbed by tillage and puddling. In Experiment 3, in lieu of using seeds from the collected seed bank, the number of annual seedlings of S. juncoides (and the proportion of resistant individuals amongst them) were observed for three years in a commercial rice field.
In Experiment 1, the seed viability of the resistant plants was no different from that of susceptible plants for 30 to 40 months. In Experiment 2, no statistical differences were observed between biotypes in the annual emergence and seed viability during three years. However, the emergence of the resistant biotype was slightly higher, and the seed viability of the resistant biotype slightly lower, than the susceptible biotype in disturbed conditions. In Experiment 3, the proportion of resistant individuals was consistently 70 to 80% over three years.
These results suggest that the difference in seed viability in soil between biotypes was not obvious, and that long-term control will be necessary in rice fields infested with resistant plants since seed viability of resistant S. juncoides is as high as the susceptible biotype.View full abstractDownload PDF (1177K) -
Nobumasa Ichizen, Takayoshi Nishio2003 Volume 48 Issue 1-2 Pages 9-12
Published: May 31, 2003
Released on J-STAGE: December 17, 2009
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Teruo Terasawa, Shohei Hirose2003 Volume 48 Issue 1-2 Pages 13-16
Published: May 31, 2003
Released on J-STAGE: December 17, 2009
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Kenji Usui2003 Volume 48 Issue 1-2 Pages 17-23
Published: May 31, 2003
Released on J-STAGE: December 17, 2009
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Osamu Watanabe, M. Yokoyama, S. Fujita, T. Miyazaki, N. Wada2003 Volume 48 Issue 1-2 Pages 24-30
Published: May 31, 2003
Released on J-STAGE: December 17, 2009
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Jianqiang Zhu, Xin Yuan, Masayoshi Satoh2003 Volume 48 Issue 1-2 Pages 31-33
Published: May 31, 2003
Released on J-STAGE: December 17, 2009
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Yukari Sunohara, Masatoshi Gohbara, Shizuko Ishikawa, Yuichiro Nakayam ...2003 Volume 48 Issue 1-2 Pages 47-59
Published: May 31, 2003
Released on J-STAGE: December 17, 2009
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Motoaki Asai2003 Volume 48 Issue 1-2 Pages 66-67
Published: May 31, 2003
Released on J-STAGE: December 17, 2009
JOURNAL FREE ACCESSDownload PDF (191K)
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