2011 Winter broadleaf weed ID WEB.pdf

Transcript

1. Winter broadleaf look-a-like weeds Joe Armstrong Small Grains Weed Science Extension Specialist www.weedscience.okstate.edu Twitter: @OSUWeedSci
2. Winter broadleaf look-a-like weeds Many winter annual broadleaf weeds have rosette growth habits in the fall, winter, and early spring and look very similar to one another. As with grass weeds, proper identification of the weed is the first step in choosing the appropriate herbicide.
3. Leaf margins have very deep lobes bushy wallflower or treacle mustard © Joe Armstrong, Oklahoma State University
4. bushy wallflower or treacle mustard Once the plant bolts, the margins of the upper leaves look like a bread knife © Joe Armstrong, Oklahoma State University
5. Seedlings will often have small red spots on the leaves cutleaf evening primrose © Joe Armstrong, Oklahoma State University
6. cutleaf evening primrose Leaves have a smooth, leathery appearance and remain very flat to the ground © Joe Armstrong, Oklahoma State University
7. Leaves have several small serrations along margin prickly lettuce © Joe Armstrong, Oklahoma State University
8. Leaves contain a milky sap Can be easily identified by the row of spines along the bottom of the leaf prickly lettuce © Joe Armstrong, Oklahoma State University
9. Leaves typically have rounded tips and several coarse hairs marestail © Joe Armstrong, Oklahoma State University
10. marestail Leaves also have several small, shallow lobes © Joe Armstrong, Oklahoma State University
11. Most plants have leaves with very deep lobes shepherd’s-purse © Joe Armstrong, Oklahoma State University
12. shepherd’s-purse However, the shapes of the leaves can vary widely among individual plants © Joe Armstrong, Oklahoma State University © Joe Armstrong, Oklahoma State University
13. flixweed Leaflets are very finely lobed and typically have a gray or blue color © Joe Armstrong, Oklahoma State University
14. All photos, unless noted, were taken by Joe Armstrong. If you would like high resolution versions of these photographs, please contact Joe at joe.armstrong@okstate.edu.