The basic definition of a superweed is one that is tolerant of the chemical glyphosate and resistant to multiple herbicides modes of action.This also includes 2,4D,dicambia,and others.They currently affect 60-70 million A. and thus promoting more use of herbicides.Another concern has been whether GM crops have lead to the development of superweeds.The conclusion I read is they do not.
Also there are over 30 species of weeds now tolerant of herbicides.The list is as follows:smooth pigweed,palmer amaranth,spinny amaranth,tall waterhemp,common and giant ragweed,hairy begartracks,sweet summer grass,ripgut brome.red brome,tall windmill,windmill grass,hairy flebane,horseweed,summertime fleabane,sourgrass,woody borreria,kochia,topical strangletop,perennial ryegrass,italian ryegrass,rigid ryegrass,buckorn plantain,annual bluegrass,wild radish,annual sowthistle,johnson grass,goosegrass,junglerice,liverseedgrass.This list includes the entire planet to date.
Thanks to weedcontrolfreaks.com and weedscience,org.
As always my mission is “what’s that weed?”
pics from:gobotany.newenglandwild.org and abc.net.au.