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Few Changes in N.D. Weed Trends There have been many changes in the herbicide arena since 1945, when 2,4-D was registered, ushering in the modern era of weed control. Major products joining the fight included Atrazine in the 1950s, Treflan in the 1960s and Roundup in the 1970s. There was a veritable explosion of herbicide registrations in the 1980s, including such products as Glean, Ally, Harmony, Express, Flexstar, Assert and Poast. According to Richard Zollinger, extension weed specialist at North Dakota State University, just one thing has changed very little, at least since about 1978. The list of usual suspects for “Weed of the Year” honors in North Dakota has changed very little. NDSU’s first weed survey in 1978/79 was the first statewide effort to measure weed distribution and population in selected fields using scientific statistical methods. The survey was repeated in 2000 The 1978 survey identified the 15 most common weeds in North Dakota. Heading the list that year was green foxtail, followed by wild oat, wild buckwheat, pigweeds, yellow foxtail, common lambsquarters, wild mustard, Russian thistle, kochia, field bindweed, Canada thistle, perennial sowthistle, quackgrass, common ragweed and cocklebur. The statewide survey was repeated in 2000 to see how the weed situation had changed over the years. The 2000 survey was conducted in both spring and summer. In the spring survey the number one weed on the list was…green foxtail, hanging on to its top ranking from 1978. Number two was wild mustard, moving up from its number seven spot in the earlier survey, followed by wild buckwheat, holding steady in number three, just like in 1978. In fact, the 14 most common weeds were the same as in 1978, with some jostling for position. One newcomer on the 2000 list was eastern black nightshade in the number 14 slot, replacing perennial sowthistle, number 12 in 1978. The summer 2000 survey was also largely lacking in surprises. The number one position was again held by green foxtail, but this time joined by family member yellow foxtail. Sowthistle rejoined the top 15 list, but this time in a tie with milkweed. Eastern black nightshade dropped off the screen from the earlier survey. Zollinger notes a change from 1978 in the number of “weed free” fields that were surveyed. No field is actually free of all weeds, but in the survey process weed counts were taken in 0.5 meter by 0.5 meter quadrants in a pattern throughout the sampled fields. When one or more of these quadrants were found to contain no weeds, the field was noted as a “weed free” field. In the 1978 survey, 36% of sampled fields were designated weed free. In the summer 2000 survey, 54% of sampled fields were considered weed free. In the world of weeds and weed control, it seems, some things remain the same but others change. One change that Zollinger finds worrisome is that some herbicides are disappearing from the marketplace, mainly because they are no longer profitable for the manufacturer. If herbicide resistance in the weed population continues, there will be fewer alternative products, making it more difficult to use different modes of action in control efforts.
15 Most Common Weeds in North Dakota
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