International Survey of Herbicide Resistant Weeds April 27,2015 There are currently 452 unique cases (species x site of action)of herbicide resistant weeds globally, with 245 species(142 dicots and 103 monocots). Weeds have evolved resistance to 22 of the 25 known herbicide sites of action and to 157 different herbicides. Herbicide resistant weeds have been reported in 86 crops in 66 countries. The website has 2064 registered users and 473 weed scientists have contributed new cases of herbicide resistant weeds. There are currently 452 unique cases (species x site of action) of herbicide resistant weeds globally, with 245 species (142 dicots and 103 monocots). Weeds have evolved resistance to 22 of the 25 known herbicide sites of action and to 157 different herbicides. Herbicide resistant weeds have been reported in 86 crops in 66 countries. The website has 2064 registered users and 473 weed scientists have contributed new cases of herbicide resistant weeds. April 27, 2015 International Survey of Herbicide Resistant Weeds