Progress 09/15/01 to 09/14/04
Outputs
This national program funded 29 research projects and two technology transfer projects in nine western states and involved 38 scientists. Extending a wheat-fallow rotation to three years by adding a spring or summer crop reduced the density of jointed goatgrass by 90% or more. Extending the rotation to four years by adding two spring or summer crops reduce jointed goatgrass populations to near zero. Other than extending the length of the crop rotation, single cultural control practices generally had a small and inconsistent effect on jointed goatgrass populations in winter wheat. However, when several cultural control practices, such as one-time stubble burn, higher wheat seeding rate, planting larger wheat seed, deep-banding nitrogen fertilizer, or selecting more competitive wheat cultivars, were used in an integrated management system, jointed goatgrass was suppressed and wheat yields and quality were increased. Drought conditions or winter injury to the wheat
reduced the competitiveness of the crop, allowed jointed goatgrass to flourish and often eliminated any benefit of the integrated cultural practices system. Timing and intensity of fallow tillage had an inconsistent effect on reducing jointed goatgrass in the subsequent winter wheat crop. Timing and duration of rains in September and October had a major effect on emergence and competitiveness of jointed goatgrass in winter wheat. Seed set on hybrids of wheat by jointed goatgrass crosses varied from 0.3 to 4.9%. Overall germination of BC1 seed was 83%. Mean chromosome number of BC1 plants was 42.1 with a range of 33 to 56, and the mean genome number was 5.9 with a range of 4 to 11. Only 8% of the BC1plants were produced by a backcross to jointed goatgrass. Spring germinating jointed goatgrass was shorter, had fewer tillers and spikelets, and had lower germination than fall germinating jointed goatgrass grown at the same location. Seed from spring germinating jointed goatgrass
germinated faster than seed from fall germinating jointed goatgrass. Jointed goatgrass that germinated before mid-March in Pendleton, OR, or before late-March in Moro, OR, produced viable seed. Control of jointed goatgrass in imidazolinone-resistant wheat with imazamox varied significantly between years and varied from 39% to 99%. Control was reduced when drought conditions forced the imazamox application to be delayed from fall to spring. Two national jointed goatgrass bulletins were published, one introducing the problem and the concept of a national integrated plan for managing this weed and a second bulletin on the biology and ecology of jointed goatgrass. Six more bulletins were planned. A 5-year plan was developed to bring the program to completion in 2006. The jointed goatgrass web page was redesigned, given a new address www.jointedgoatgrass.org, and updated annually. The site received over 40,000 visits in 2003.
Impacts
Producers are adopting integrated management practices to reduce the severity of jointed goatgrass and other weeds on their farms, thus improving crop yields and quality. Intense fallow tillage has little benefit for suppressing jointed goatgrass, therefore producers can reduce tillage and conserve soil moisture and reduce production costs. The low percentage of BC1plants produced by backcrossing with jointed goatgrass reduces the likelihood of gene flow from herbicide-resistant wheat to jointed goatgrass. Technology transfer activities are keeping wheat producers and the general agricultural community informed of the latest research findings from this national program.
Publications
- Anderson, R., E. Zakarison, D. Ball, G. Wicks, D. Lyon, W. Donald, S. Miller, F. Young,and T. White. 2002. Jointed Goatgrass: Ecology. National Jointed Goatgrass Research Program. Wash. State Univ. Coop. Ext. bull. EB 1932. 7 pages.
- Frandrich, L. and C. Mallory-Smith. 2003. Germination response of spring and winter cohorts of jointed goatgrass (Aegilops cylindrica). Proc. West. Soc. Weed Sci. 56:68.
- Hanavan, D., T. White, E. Zakarison, and R. Anderson. 2002. Jointed Goatgrass: Introduction. National Jointed Goatgrass Research Program. Wash. State Univ. Coop. Ext. Bull. EB 1931. 8 pages.
- Kroiss, L.J., P. Tempali, M. I. Vales, O. Riera-Lizarazu, C.A. Mallory-Smith, J.L.Hansen, and R.S. Zemetra. 2003. Molecular evidence for the retention of wheat chromatin in wheat by jointed goatgrass backcrosses. Proceedings West. Soc. of Weed Sci. 56: 94.
- White, T. and P. Stahlman. 2003. Control of jointed goatgrass using best management practices. The 6th Annual National Wheat Industry Research Forum Proceedings, Albuquerque, NM. National Association of Wheat Growers Wheat Industry Resource Committee. p.22-24.
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Progress 01/01/02 to 12/31/02
Outputs
Compared with conventional wheat, imi-resistant wheat treated with imazamox at 0.036 kg/ha reduced jointed goatgrass populations 90 to 99%, reduced reproductive tillers 90 to 100%, reduced dockage in harvested grain by 80 to 93% and increased wheat yield 0 to 27%. Imi-resistant wheat varieties appeared to be less drought tolerant than conventional wheat varieties and yielded less under drought conditions in ID and OK. Imi-resistant wheat treated with imazamox at 0.027 kg/ha and grown with best management practices reduced jointed goatgrass tillers 81% compared with 47% reduction when grown with standard growers practices. Wheat planted and grown with improved cultural practices compared to the same variety planted with standard growers practices had 65% less dockage due to jointed goatgrass. After one cycle of a wheat-fallow rotation using a conventional wheat system, jointed goatgrass tillers increased over 1200%. Adding spring safflower to a wheat-fallow rotation
reduced jointed goatgrass reproductive tillers 75% when compared with the initial jointed goatgrass tiller density. Moldboard plowing before planting wheat reduced jointed goatgrass populations 79% compared to stubble mulch tillage. Seed from 'spring' populations of jointed goatgrass were less dormant than seed from 'winter' populations. Spikelet mass did not give an adequate indication of seed dormancy and germination. Dormancy varied among 'spring' populations of jointed goatgrass grown at the same site. Precipitation patterns appear to have a greater impact on jointed goatgrass germination and emergence in fallow than timing and intensity of tillage. Seed set on jointed goatgrass x wheat hybrids collected from fields in the Pacific Northwest varied from 0.3 to 4.9%. 92% of the first backcross generation was produced by backcrossing to wheat and only 8% was produced by backcross with jointed goatgrass. Dr. Tony White was hired in May 2002 as the National Jointed Goatgrass Extension
Coordinator. He redesigned the jointed goatgrass web site and implemented it under the unique domain name of www.jointedgoatgrass.org. Since May 2002, the site has attracted an average of 30 visitors per day. Five popular press articles on recent search findings on jointed goatgrass were published in popular farm magazines such as Successful Farming, Western Stockman-Farmer, and High Plains Journal. Numerous press releases on management techniques for jointed goatgrass were published in wheat producers' newsletters.
Impacts
Field studies with imidazolinone-resistant wheat treated with imazamox shows that this technology has great potential for reducing jointed goatgrass in winter wheat, especially when used in conjunction with integrated cultural control practices. Field studies show that the severity of jointed goatgrass can be reduced greatly by adding a spring crop to the traditional two-year wheat-fallow rotation, and provide producers with an effective method to reduce jointed goatgrass and improve crop yield and quality. The low percentage of BC1 plants produced by backcrossing to jointed goatgrass reduces the chance of gene flow from herbicide-resistant wheat to jointed goatgrass. Technology transfer activities have increased wheat producers' awareness of jointed goatgrass and have made them aware of new ways to manage this weed. Producers are adopting integrated cultural practices to reduce the severity of jointed goatgrass on their farms.
Publications
- Johnson, J, S. Haley and P. Westra. 2002. Clearfield Wheat. Colo. State Univ. Coop. Ext. Fact Sheet No. 3.116. 4 pages.
- Lyon, D.J., A.J. Bussan, J.O. Evans, C.A. Mallory-Smith and T.F. Peeper. 2002. Pest management implications of glyphosate-resistant wheat (Triticum aestivum) in the western United States. Weed Technol. 16:680-690.
- Wang, Z., R.S. Zemetra, J. Hansen, A. Hang, C.A, Mallory-Smith and C. Burton. 2002. Determination of the paternity of wheat (Triticum aestivum L.) x jointed goatgrass (Aegilops cylindrica Host) BC1 plants using genomic in situ hybridization technique. Crop Sci. 42:939-943.
- Wicks, G.A., G.E. Hanson, and G.W. Mahnken. 2002. Progress report on controlling jointed goatgrass in winter wheat in Nebraska with rotations, tillage and cultivars in 2001. Proc. West. Soc. Weed Sci. 55:59-60.
- Wicks, G.A., D.J. Lyon and R.N. Klein. 2002. Controlling jointed goatgrass. Univ. of neb. NebGuide G95-1252-A. 4 pages.
- Zemetra, R.S., C.A. Mallory-Smith, J. Brown, D.C. Thill, O. Riera-Lizarazu, M.I. Vales, J.L. Hansen, Z. Wang, J. Snyder and S.L. Kunzli. 2002. Natural gene introgression between plant species: Beneficial or detrimental? Plant and Animal Genome Abstracts 10:61
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Progress 01/01/01 to 12/31/01
Outputs
Long-term field experiments have been established in ten sites in seven western and mid-western states to determine the best strategy to introduce imidazolinone-resistant wheat technology into winter wheat cropping systems for the control of jointed goatgrass. Imazamox at 0.035 to 0.044 kg/ha controlled jointed goatgrass 95 to 100% in imidazolinone-resistant wheat without visible crop injury. In CO and WA, imidazolinone-resistant wheat yielded similar to standard wheat varieties, whereas in eastern WY and northern UT, standard varieties yielded 10 to 28% more than the imadazolinone-resistant wheat. Jointed goatgrass in spring crops had lower populations, shorter height, delayed maturity and fewer reproductive tillers than jointed goatgrass in winter wheat. Chromosome numbers ranged from the high 30s to high 40s in naturally produced wheat x jointed goatgrass hybrids collected from fields in ID, OR and WA. Genomic in situ hybridization analysis techniques are being
used to determine the pollen parent of the first backcross plants from hybrids x jointed goatgrass crosses. Microsatellite analysis of chloroplast DNA is being tested as a method to determine the maternal parent of hybrids. Seed from plants grown in a Nelder wheel plot are being tested for the occurrence of an herbicide-resistant gene to determine the distance viable pollen will move. Nine popular press articles and news releases authored by the Extension Coordinator appeared in regional agricultural publications. Extension Coordinator participated in or arranged for six radio interviews the presented new research findings on jointed goatgrass management. The jointed goatgrass Web page http://jgg.unl.edu continued to be expanded with the addition of more articles, news releases, events calendar, and photographs. The Extension Coordinator lead or participated in writing of first drafts of the first two bulletins in a series on fundamentals of jointed goatgrass management.
Impacts
Long-term field studies to determine the best strategy to introduce imidazolinone-resistant wheat into winter wheat cropping systems will help producers maximize the effectiveness of the technology for the control of jointed goatgrass and insure its longevity. Technology transfer activities and up-dates to the jointed goatgrass Web page increased producers' awareness of the jointed goatgrass problem and have alerted them to the most recent research findings that will help them combat this weed. Even though jointed goatgrass was not robust in spring crops, the plants still produced some viable seed, thus explaining why the repeated use of spring crops has not eliminated this weed.
Publications
- No publications reported this period
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