Posted 5 June 2009. Crop Management.

Identify "Early Season" Weeds

University of Illinois at Urbana-Champaign. aces.illinois.edu

Urbana-Champaign, Illinois (May 22, 2009)--As temperatures have finally warmed up in this spring, no-till fields or fields with delayed tillage can rapidly "green up" from the growth of winter and early-summer annual weed species. Knowing what species are present by correct identification is the first step to effective control. Some of the early season weeds may be less common to some producers and possibly more difficult to identify for control purposes.

Two University of Illinois websites can offer help with identification. "Color pictures of many of the early species and a brief description are available at the sites," says John Church, University of Illinois Extension Educator, Natural Resources, Rockford. The first site is from the University of Illinois Extension Pest Management and Crop Development Bulletin at ipm.uiuc.edu/bulletin. A number of winter annual pictures, comparisons and descriptions of weed species and their families is included in a fact sheet format. Also available on the University of Illinois website is the North Central Region University publication, NCR 614, "Early Spring Weeds of No-till Crop Production". It is at weeds.cropsci.uiuc.edu.

For Illinois control recommendations, information is available from the 2009 weekly updates of the Bulletin newsletter which is on line at www.ipm.uiuc.edu/bulletin and from the University of Illinois Agricultural Pest Management Handbook on the web at ipm.uiuc.edu/pubs. Publications are also available through U. of I. Extension offices.