Herbicide-resistant weed biotypes in the Unites States, 1987-2012.

Herbicide resistant weed biotypes documented in the United States between 1987 to 1999 (circles) and between 2000 to 2012 (triangles). Glyphosate-resistant cultivars reached 50% of US soybean acreage in 2000. This figure illustrates trends in herbicide resistant weeds before and after widespread adoption of glyphosate-resistant cultivars. Resistance to glyphosate (glycines) increased significantly after adoption of glyphosate-resistant crops, but the rate of resistance development to all other herbicide modes of action slowed significantly. Data from: Heap, I. The International Survey of Herbicide Resistant Weeds. Online. Internet. Monday, November 03, 2014 . Available www.weedscience.org.