Johnsongrass (Sorghum halepense (L.) Pers.) is a perennial weed originating from the Mediterranean. it is classified as an invasive species in some countries. It is an important weed in cotton production, which is among the foremost crops of Turkey. It is estimated that 61% of cotton production areas are infested with johnsongrass. The crop loss at average infestation levels varies from 13% to 54% depending on the region. If johnsongrass was not controlled, 38% of current cotton production would be lost. The impact of control of johnsongrass in cotton is 165 million Euro in Turkey.