North
Dakota State University -- NDSU Agriculture
Communication7 Morrill Hall, Fargo ND, 58105-5655, Tel: 701-231-7881, Fax: 701-231-7044
agcomm@ndsuext.nodak.edu
|
North
Dakota State University -- NDSU Agriculture
Communication 7 Morrill Hall, Fargo ND, 58105-5655, Tel: 701-231-7881, Fax: 701-231-7044 agcomm@ndsuext.nodak.edu |
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June 5, 2003 |
Canada Thistle Creates Big Yield Loss in Hard Red Spring WheatData from a just-released weed survey shows Canada thistle caused more yield loss in spring wheat, durum and barley than any other weed, according to Rich Zollinger, North Dakota State University weed specialist. "According to the survey, the yield loss was 35.5 million bushels." A similar survey conducted back in 1978 and 1979 showed that wild oat caused the most yield loss in spring wheat, durum and barley. The yield loss from Canada thistle during that survey was 9 million bushels. Other weeds that are causing considerable damage according to the 2000 survey are wild oat, field bindweed, common milkweed, kochia and green and yellow foxtail. "The infestation frequency for Canada thistle, field bindweed and common milkweed was much less than some other weeds such as wild oat or foxtail," according to Zollinger. "However they are more than twice as competitive causing greater yield losses in small grains." Zollinger is an associate professor of plant sciences at NDSU and a weed specialist with the NDSU Extension Service. The average total yield loss in spring wheat, durum and barley in 1978 and 1979 from seven weeds, where loss information is available, was 55.6 million bushels. Those same seven weeds reduced yields by 83.4 million bushels in the 2000 survey. If you include weeds that didn’t show up in the 1978 and 1979 survey, the yield losses are even higher. Weeds added to the list in the 2000 include lanceleaf sage, eastern black nightshade, Venice mallow, swamp smartweed, biennial wormwood, waterhemp and yellow nutsedge. When added to the other weeds, total yield loss in the 2000 survey was over 115 million bushels. Weeds that were reported in the 1978 and 1979 survey but were no longer found in the 2000 survey were wild prairie rose and night-flowering catchfly. "Information gathered in the survey gives us important information to use when we seek Section 18 emergency approvals," Zollinger says. Section 18 "emergency" and "crisis" exemptions from registration are used when emergency or crisis pest situations arise for which no pesticide is registered with the North Dakota Department of Agriculture. Both types of exemptions from registration allow use of a pesticide for a non-registered purpose for a specified period of time. The results from the 2000 survey also show that several weeds continue to infest other small grains causing major production losses. Canola Soybean and dry bean Losses in sunflower "The 2000 surveys along with the 1978 and 1979 weed surveys provide information on weed infestations for present and future herbicide benefit analysis," Zollinger says. "It also serves as a basis for showing weed population shifts that have occurred and those that may occur in the future, especially since glyphosate has become a major component in weed control systems." The survey cost $120,000 to complete of which $95,000 was funded by the North Dakota Department of Agriculture Minor Use Fund and $25,000 by the NDSU Department of Plant Sciences. The complete 2000, 1979 and 1978 surveys can be found on the Web at www.ag.ndsu.nodak.edu/weeds/ and will also soon be available from the NDSU Extension Distribution Center. The Survey of Weeds in North Dakota - 2000 will be Extension Report number 83. ### Source: Rich Zollinger, (701) 231- 8157,
richard.zollinger@ndsu.nodak.edu |