Progress 03/01/01 to 02/29/04
Outputs
Objective 1. A study was conducted in 1998 and 2000 to determine if using larger sized seed of a tall wheat variety at an increased seeding rate would individually or interactively reduce the impact of jointed goatgrass on a winter wheat crop. Wheat seed size, seeding rate, and variety height had no impact on jointed goatgrass plant density. Of these wheat traits, plant height most consistently affected jointed goatgrass. Tall (~130 cm) wheat reduced mature jointed goatgrass biomass 46 and 16% compared to short (~100 cm) wheat in years one and two of the experiment, respectively. Spikelet biomass was also reduced approximately 70 and 30% in the same respective years. Thousand-spikelet weight of jointed goatgrass was also reduced 37 and 7% in years one and two, respectively, when grow in competition with taller wheat compared to shorter wheat. Moreover, dockage was 80 and 30% greater in years one and two, respectively, when grown in competition with taller than shorter
wheat. Mature jointed goatgrass height was generally similar regardless of the height of the competitive wheat. However, jointed goatgrass was as much as 18% taller than the short wheat and as much as 15% shorter than the tall wheat. Seeding rate had the most consistent effect on wheat yield compared to plant height and seed size. Wheat seed yield was about 10% greater with 60 than 40 seed/m of row when wheat competed with jointed goatgrass. Objective 2. Jointed goatgrass is most commonly described as a winter annual species. However, it has been observed to produce spikes in spring crops, apparently without being exposed to vernalizing conditions. A controlled environment study was conducted to determine the reproductive response of jointed goatgrass plants grown from seeds of fall- and spring-emerging parent plants to various vernalization durations. Winter wheat was included as a control. Winter wheat spikelet production was dependent on vernalization, and the number of spikes per
plant was 10-fold greater if the plants were exposed to 4 C for 10 wk. In contrast, jointed goatgrass spike production without vernalization remained as high as 50% of that produced by plants exposed to 10 wk of vernalization conditions. Jointed goatgrass is thus not as dependent on vernalization for reproduction as the comparative winter wheat standard. Apparently, jointed goatgrass is more a facultative rather than an obligate winter annual. Rotating to a spring-seeded crop should not be expected to completely prevent jointed goatgrass seed production. Fields rotated to spring wheat to eliminate jointed goatgrass seed production should be monitored, and jointed goatgrass should be hand pulled or otherwise controlled to ensure zero seed production.
Impacts
Improved methods of weed management using herbicide technology or integrating crop management practices for the cultural control of weeds have been discovered. These discoveries will allow for improvements in the economic aspects of farming and the environmental quality of eastern Washington.
Publications
- Ball, D. A., J. P. Yenish, and T. Alby III. 2003. Effect of imazamox soil persistence on dryland rotational crops. Weed Technol. (17:161-165).
- Young, F. L., J. P. Yenish, D. L. Walenta, and D. A. Ball. 2003. Spring-germinating jointed goatgrass produces viable spikelets in spring seeded wheat. Weed Sci. (51:379-385)
- Walenta, D. L., J. P. Yenish, F. L. Young, and D. A. Ball. 2002. Vernalization response of plants grown from spikelets of spring and fall cohorts of jointed goatgrass. Weed Sci. (50
- Rainbolt, C. R., D. C. Thill, J. P. Yenish, and D. A. Ball. 2003. The effect of weed seed biology and selection pressure on the evolution of resistant weed populations in imidazolinone-resistant wheat production systems: A Pacific Northwest extension publication. Abstr. Weed Sci. Soc. Am. 43:16.
- Ireland, T. M., D. C. Thill, J. Yenish, and D. Ball. 2002. Annual grass control in stubble in the Inland Northwest. Proc. West. Soc. of Weed Sci. 54:66-67.
- Yenish, J. P. and F. L. Young. 2004. Winter wheat competition against jointed goatgrass as influenced by wheat plant height, seeding rate, and seed size. Weed Sci. (Accepted February 2004).
- Yenish, J. P., D. L. Walenta, F. L. Young, D. A. Ball, and E. Gallandt. 2001. Jointed goatgrass seed production in spring wheat. Proc. West. Soc. of Weed Sci. 54:66-67.
- Ball, D. A., C. Rainbolt, D. C. Thill, and J. P. Yenish. 2003. Weed management strategies for CLEARFIELD wheat systems across PNW precipitation zones. Northwest Direct Seed Cropping Systems Conference and Trade Show. pp. 90-96.
- Ireland, T. M., D. C. Thill, J. P. Yenish, and D. A. Ball. 2003. Evaluation of glyphosate formulations for burndown in direct seed systems. Northwest Direct Seed Cropping Systems Conference and Trade Show. pp. 97-104.
- Rainbolt, C., D. C. Thill, J. P. Yenish, and D. A. Ball. 2003. Alternatives to glyphosate as part of a resistance management strategy in direct seed systems. Northwest Direct Seed Cropping Systems Conference and Trade Show. pp. 105-118.
- Rainbolt, C., D. Thill, D. Ball, J. Yenish and F. Young. 2001. Managing volunteer after herbicide-resistant crops. Northwest Direct Seed Cropping Systems Conference and Trade Show. pp. 115-123.
- Yenish, J. P., J. Toker, and E. Scheenstra. 2003. 2002 eastern Washington weed control report. Department of Crop and Soil Sciences, Washington State University, Tech. Rep. 03-1, 74pp.
- Yenish, J. P., J. Toker, E. Scheenstra, and E. Zakarison. 2002. 2001 eastern Washington weed control report. Department of Crop and Soil Sciences, Washington State University, Tech. Rep. 02-4, 107pp.
- William, R. D., A. G. Dailey, D. A. Ball, J. Colquhoun, T. L. Miller, R. Parker, J. P. Yenish, T. W. Miller, D. W. Morishita, P. J. S. Hutchninson, and M. Thompson. 2003 Pacific Northwest Weed Control Handbook. MISC0049, 420pp.
- William, R. D., D. Ball, T. Miller, R. Parker, J. P. Yenish, T. Miller, D. W. Morishita, and P. Hutchninson. 2002 Pacific Northwest Weed Control Handbook. MISC0049, 420pp.
- William, R. D., D. Ball, T. Miller, R. Parker, J. P. Yenish, T. Miller, D. W. Morishita, and P. Hutchninson. 2001 Pacific Northwest Weed Control Handbook. MISC0049, 375pp.
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Progress 01/01/03 to 12/31/03
Outputs
Over 35 weed management studies were conducted in eastern Washington during 2003. This research was conducted in all major crops of the area. Weed control research in agronomic crops focused on the major winter and spring annual weeds. Additional research was also conducted on broadleaf weed control under range management. Primary species researched included, jointed goatgrass, downy brome, Italian ryegrass, wild oats, and Russian thistle in cropping systems as well as yellow starthistle, scotch thistle, and rush skeletonweed in range systems. Much of the weed control research on cropping systems was done under direct seed systems. Direct seed systems provide both environmental and economic benefits, however, poor weed control is a primary reason state for lack of adoption. Improved chemical, cultural, and integrated control of weeds is needed to ensure the success of direct seed systems. Research was completed on optimum rates and timings of sequential nonselective
herbicide application for direct seed systems. That research project was a collaborative effort between Washington State University, Oregon State University, and the University of Idaho. Most of the weed control research is done collaboratively with those and other universities and USDA-ARS scientists. While much of the research focused on herbicides as the primary management tool, research also focussed on weed/crop ecology and biology and the potential to integrate weed management into production systems. Specific discoveries in the area of weed ecology and biology include determining the benefits of increased seeding rates and the use of taller wheat varieties to minimize the impact of jointed goatgrass. Another significant study was to quantify and characterize seed production of spring emerging jointed goatgrass, a species largely considered to be winter annual in biology. More effective use of spring crops to manage jointed goatgrass in crop rotations will result from this
research.
Impacts
Improved methods of weed management using herbicide technology or integrating crop management practices for the cultural control of weeds have been discovered. These discoveries will allow for improvements in the economic aspects of farming and the environmental quality of eastern Washington.
Publications
- Ball, D. A., J. P. Yenish, and T. Alby III. 2003. Effect of imazamox soil persistence on dryland rotational crops. Weed Technol. 17:161-165.
- Young, F. L., J. P. Yenish, D. L. Walenta, and D. A. Ball. 2003. Spring-germinating jointed goatgrass produces viable spikelets in spring seeded wheat. Weed Sci. 51:379-385.
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Progress 01/01/02 to 12/31/02
Outputs
Winter annual grass weeds continue to be the most important pest of winter wheat production. During 2002, research continued on jointed goatgrass, downy brome, Italian ryegrass, wild oats, rattail fescue, and other winter annual grass species. Research continues on the potential development of herbicide resistant jointed goatgrass within herbicide resistant cropping systems. The field component of a collaborative research project on volunteer grain and winter annual grass control concluded. Tom Ireland, a graduate student at the University of Idaho is completing his thesis on that project. Additionally, two articles were accepted for publication in refereed journals. Grant proposals for research on rattail fescue management and chemical fallow management were fully and partially funded, respectively.
Impacts
Over 2,000 growers received information on this project directly from extension presentations, articles,and personal contact. The area affected is estimated at 1,500,000 acreas of eastern Washington cropland.
Publications
- Walenta, D.L., Yenish, J.R., Young, F.L. and Ball, D.A. 2002. Vernalization response of plants grown from spikelets of spring and fall cohorts of jointed goatgrass. Weed Sci. 50: 461-465.
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