2014 Weed Resistance Workshops


Stevan Knezevic
Northeast Research & Extension Center

Lowell Sandell
174 Keim Hall

Bob Wilson
Pandhandle Research & Extension Center

Amit Jhala
173 Keim Hall

Weed Resistance Workshops 2014

Please join us for a Weed Resistance Workshop available at four locations:

Kearney, Jan. 23 – Register online
Scottsbluff, Jan. 24 – Register online
Beatrice, Jan. 27 – Register online
Columbus, Jan. 28 – Register online

9 a.m.
Cost: $30
Open to the public - limited to 30 participants

Weed resistance to herbicides is not a new thing. It began to occur as soon as man started using chemicals for weed control. Weed scientists predicted in the mid-1950s that repeated use of any herbicide could lead to a shift in weed species, and that herbicide tolerance in weeds can increase with repeated use of the same herbicide. Very soon after that—early-1970s—the first cases of weed resistance occurred in pigweed species showing resistance to atrazine. There is well documented literature about weed resistance. Worldwide about 368 herbicide-resistant weed biotypes reported to be resistant to 19 different herbicide modes of action. For example, 40 dicot and 15 monocot species are known to have biotypes resistant to triazine herbicides. Also, at least 50 weed species have been reported to have biotypes resistant to one or more herbicide families (www.weedscience.com). Repeated use of the same herbicide was always the main reason for weed resistance to herbicides worldwide.

Therefore the main objective of this workshop is to educate agricultural clientele and farmers about the importance of herbicide mode of action, and how to use the Site of Action Numbering System to reduce potential for weed resistance in Nebraska.

A workshop will be offered at four locations, including Kearney on Jan. 23 (host Educator Brent Plugge); Scottsbluff on Jan. 24 (host Educator Jim Schild); Beatrice on Jan. 27 (host Educator Paul Hay); and Columbus on Jan. 28 (host Educator Allan Vyhnalek.) Registration is limited to only 30 participants.

It is a minimum 3-hour long workshop, which will start with several topics for discussions, and then active involvement by attendees. Topics for discussion will include Herbicide Tolerant Crops, Herbicide Mode of Action and Site of Action Groupings, How Weed Resistance Develops, and Weed resistance in the Midwest and Nebraska. Attendees will also have a chance to conduct Hands-On Exercises on Weed Resistance Problems (eg. Waterhemp, Giant ragweed, and Kochia).

Workshops speakers are members of the UNL Weed Science Panel, including Bob Wilson, Amit Jhala, Lowell Sandell and Stevan Knezevic (lead). For more information, contact your host county educator, or Steve Knezevic or Wendy Winstead.

Kearney – Buffalo County Extension Building, 1400 E. 34th St., Kearney, NE, 308-236-1235
Scottsbluff – Panhandle Research and Extension Center, 4502 Avenue I, Scottsbluff, NE, 308-632-1230
Beatrice – Gage County Extension Office, 1114 W. Scott Road, Beatrice, NE
Columbus – Club Room, Ag Park, 822 15th St., Columbus, NE, 402-563-4901



This workshop is sponsored by an educational grant from the United Soybean Board.

United Soybean Board logo