Archive for the ‘Glyphosate’ Category

MSU 2013 WSSA posters available

Thursday, February 7th, 2013

-E. Taylor-Hill

We just returned from Baltimore, MD (home of the 2013 Superbowl Champions) where we attended the 2013 Weed Science Society of America annual meeting. It was a great opportunity to look at weed related research from around the nation and beyond and to take a look at how the rise in herbicide resistant weeds seems to be impacting agriculture across the U.S. (look for a future blog on that).

Now that we are back I posted the 3 posters that we presented. Our topics included…

  • Influence of soil amendments on seed mortality of herbicide resistant Palmer amaranth
  • Volunteer glyphosate resistant (RR) corn control in RR sugarbeets
  • Cover crop influence on weed pressure in organic dry beans

Visit the Presented Research section to view the posters.

Palmer amaranth in MI- 2 updated extension publications

Friday, March 2nd, 2012

-E. Taylor

Palmer Identification 2_Page_1Glyphosate-resistant palmer amaranth is still a very new weed to Michigan. We have updated two extension publications regarding the identification (MSUWS01-2012) and confirmation and management (MSUWS02-2012) based on our ongoing research program to combat the spread of this prolific weed. You can view and print these publications by following the above links or in their permanent home in the Extension Publications section of

Summer annual seed development 2011

Tuesday, August 23rd, 2011

-E. Taylor

This year we are continuing to study the post-“kill” development of seeds on summer annual weeds in correlation with stage of reproduction and method of termination. This year we have received funding from Project GREEEN to add some additional species to our study and to include the use of glyphosate (i.e. Roundup) as a termination method. We are interested to know if glyphosate will decrease seed development on immature plants or will it decrease viability of seed in mature plants compared to physical methods of termination? Pictured below are mesh bags placed over plants that have been sprayed with glyphosate. The bags ensure that we will be able to recover any seeds produced once the plant has dried down completely.


Glyphosate-resistant Palmer amaranth confirmed in Southwest Michigan

Tuesday, April 26th, 2011

-Christy SpraguePalmer_amaranth_2011_Sprague

Michigan now has a second weed that can be added to the list of glyphosate-resistant weeds.  In 2007, horseweed (marestail) was the first weed confirmed resistant to glyphosate (Roundup) in Michigan.  This past season, a grower in Southwest Michigan reported that he was not able to control “pigweed” in his soybean field with glyphosate.  We identified this pigweed species as Palmer amaranth, a weed not common to the northern U.S.  Through greenhouse testing we have confirmed that this population of Palmer amaranth is resistant to glyphosate. The combination of this being the first report of Palmer amaranth in Michigan and that this weed is resistant to glyphosate should be a concern for Michigan growers.  To help with the identification and possible management strategies for this weed, we have developed two fact sheets Palmer amaranth in Michigan: Keys to Identification and Glyphosate-resistant Palmer amaranth in Southwest Michigan: Confirmation and management options. These fact sheets outline what we know about this weed. We are also trying to track the spread of Palmer amaranth in Southwest Michigan. If you believe that you have glyphosate-resistant Palmer amaranth, please see the contact information at the end of each factsheet.

Earlier this year glyposate-resistant marestail was confirmed in Ionia and Gratiot countries. For more information on glyphosate-resistant marestail please view: Horseweed Confirmed Resistant to Glyphosate in Michigan Field Crops.

Weed Warriors Series on AgDay

Monday, April 11th, 2011

-E. Taylor

MSU Weed Science was featured on AgDay today for the Weed Warriors series, a collaborative effort of AgDay and the Farm Journal. Dr. Christy Sprague was interviewed regarding Palmer amaranth, a member of the pigweed family. Typically this is a weed found in the Southern U.S., but it has recently been found in Michigan and we are investigating the possibility that the Michigan population is resistant to glyphosate. Below is the MSU video segment. The entire AgDay recording for Monday, April 11, 2011 can be viewed at Stay tuned to the Weed Warrior series through out the week on AgDay for more reports from around the country and visit Weed Warrior News on the Farm Journal site.