Scout your fields for weed seedlings this spring

Liz Bosak, Outreach Specialist, Department of Agronomy

The fields may look cold, wet, and dormant this week but weeds were germinating in some fields in Janesville and Arlington last week. On April 17 at Janesville, common lambsquarters, giant ragweed, and horseweed were emerging (Fig. 1A-D). At Arlington in a plowed area, velvetleaf was emerging (Fig. 2). If you are leasing new land this year or want to get a head start on weed management, then scouting for weeds at the seedling stage before tillage can be a good way to assess density, the number of weeds in a given area, and for which weed species will likely be an issue around planting time. The Weedometer, developed by University of Wisconsin, can predict when weed species will likely be emerging for your location at http://weedecology.wisc.edu/weedometer/. A guide to identifying the “Common Weed Seedlings of the North Central States” is available in pdf and print formats at Cooperative Extension’s Learning Store, http://learningstore.uwex.edu/Common-Weed-Seedlings-of-the-North-Central-States-P161.aspx or on the WCWS Weed info page, http://wcws.cals.wisc.edu/weed-info/.

Figure 1. A) Common lambsquarters, Chenopodium album; a soil sampler, one inch diameter, is in the foreground B) Horseweed (marestail), Conyza canadensis; C) Giant ragweed, Ambrosia trifida, with seed capsule attached; D) Giant ragweed seedlings.

Figure 1. A) Common lambsquarters, Chenopodium album; a soil sampler, one inch diameter, is in the foreground B) Horseweed (marestail), Conyza canadensis; C) Giant ragweed, Ambrosia trifida, with seed capsule attached; D) Giant ragweed seedlings.

 

 

 

 

 

 

 

 

 

 

 

 

Figure 2. Velvetleaf, Abutilon theophrasti, seedling.

Figure 2. Velvetleaf, Abutilon theophrasti, seedling.

Print Friendly, PDF & Email
This entry was posted in WCM newsletter, Weeds. Bookmark the permalink.

Comments are closed.