New Argentine grass resistant to glyphosate

Another grass weed has developed resistance to the herbicide, glyphosate, in Argentina. The national weed resistance knowledge network, the REM, has released a red alert on the perennial grass, Bradley grass ( Cynodon hirsutus), as having developed resistance to the herbicide. It is the sixth species of the grass family to have developed such resistance, according to REM, the others including Johnsongrass ( Sorghum halepense), which was the first to be reported back in 2006 ( Agrow No 504, p 12). Lolium multiflorum, L perenne and Avena fatua, are among a total of seven species to have been reported as glyphosate-resistant, it adds. The initial reported occurrence came in 2009 from the Cordoba province, and some 600 ha are estimated to have been affected.