Full TGIF Record # 97289
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Web URL(s):http://www.wsweedscience.org//wp-content/uploads/proceedings-archive/2003.pdf#page=91
    Last checked: 12/10/2013
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Publication Type:
Content Type:Abstract or Summary only
Author(s):Ball, Dan A.; Thill, Donn C.; Ensminger, Mike; Howatt, Kirk; Seefledt, Steve; Banks, Phil A.; Anderson, Randy L.
Author Affiliation:Ball, Thill, Ensminger, Howatt, and Seefledt: Weed Scientists; Banks: Consultant; and Anderson: Agronomist, WSWS Herbicide Resistance Committee, Newark, California
Title:Development of weed resistance as affected by frequency of herbicide application
Section:Basic science (project 6)
Other records with the "Basic science (project 6)" Section
Meeting Info.:Coeur D'Alene, ID: March 12-15, 2001
Source:Proceedings of the Western Society of Weed Science. Vol. 56, 2003, p. 89-90.
# of Pages:2
Publishing Information:Newark, CA: Western Society of Weed Science
Keywords:TIC Keywords: Herbicide resistance; Herbicide application; Application frequency; Models; Evolution
Abstract/Contents:"A key strategy for managing weed resistance is to reduce frequency of herbicide use, thus minimizing the herbicide's selection pressure on the weed community. Simulation models based on population dynamics of wild oats (Avena fatua L.) and jointed goatgrass (Aegilops cylindrica Host.) are available to predict rate of resistance development. Our objective was to quantify the impact of reducing use frequency in managing herbicide resistance. Our first case examines wild oats and its resistance to ACCase inhibiting herbicides, Cavan et al., (Weed Sci. 49:236; 2001) estimated rate of resistance development based on the frequency of ACC-inhibiting herbicides use across years. In a no-till system, resistant wild oats appeared within 13 years if ACCase-inhibiting herbicides were applied every year. If applied once every two years, resistance biotypes appeared after 30 years. A surprising trend, however, occurred when the herbicide was applied only once every three years; resistant plants did not appear until after 126 years. Applying an ACCase-inhibiting herbicide every year imposed 10-fold more selection pressure on wild oats than applying the herbicide once every three years. The contrast bewteen applying the herbicide every two years versus every three years was more than four-fold. A second simulation model evaluated the relationship between frequency of use and ALS-inhibiting herbicide resistance development in the jointed goatgrass seedbank. In this model developed by Hanson et al., (Weed Technol. 16:156-163) seedbank abundance of imazamox-resistant jointed goatgrass increased and surpassed the abundance of susceptible jointed goatgrass in the seedbank after 4 years when imazamox was used each year in continuous, imazamox-resistant winter wheat. In a winter wheat – fallow crop rotation, resistant jointed goatgrass seedbank abundance surpassed susceptible numbers after 9 years if imazamox-resistant wheat and imazamox were used every crop year. In a simulation of a winter whear – fallow crop rotation with imazamox-resistant wheat grown every other crop (once in four years), an imazamox-resistant jointed goatgrass population did not surpass the susceptible population during the 10 year simulation. These simulation models demonstrate the impact of herbicide use frequency on rate of resistance development. Selection pressure on the weed community can differ 10-fold between yearly applications and less frequent use, such as one application every three years. In some regions of the Western U.S., producers are diversifying their rotations because of no-till systems; it will help resistance management if crop sequences could be developed that reduce frequency of herbicide use within a mode of action to once every three years."
Note:This item is an abstract only!
ASA/CSSA/SSSA Citation (Crop Science-Like - may be incomplete):
Ball, D. A., D. C. Thill, M. Ensminger, K. Howatt, S. Seefledt, P. A. Banks, et al. 2003. Development of weed resistance as affected by frequency of herbicide application. Proc. West. Soc. Weed Sci. 56:p. 89-90.
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    Last checked: 12/10/2013
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    Notes: Item is within a single large file
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MSU catalog number: SB 610 .W43 v.49
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