Glyphosate-resistant and some glyphosate- and ALS-resistant horseweed found in Michigan fields: Early management is important

Christy Sprague

Glyphosate-resistant and some glyphosate- and ALS-resistant horseweed found in more Michigan fields: Early management is important (PDF)

In 2010 two horseweed samples suspected of being resistant to glyphosate were collected from a no-till soybean field and a stale seed-bed sugarbeet field in Ionia and Gratiot counties were confirmed resistant to glyphosate. In 2011 six additional horseweed samples from Lapeer, Clinton, and Washtenaw counties were confirmed resistant to glyphosate and some of these samples are multiple resistant to glyphosate and ALS-inhibitors (FirstRate and Classic), which makes this weed extremely difficult to control in soybean...(Click the link above for the full article)

Christy Sprague