Fig. 10. The rotary rodweeder is an essential implement used to control Russian thistle and other weeds in summer fallow. Typically, two or three rodweeding operations are required from May through August. The rodweeder is ground-powered and has a 2-cm square rod that rotates opposite the direction of travel at a depth of 7 to 10 cm with little disturbance to surface residue. A 30-horsepower International TD 9 crawler tractor pulls 10 m of rodweeder in this 1965 photo. Photo from Washington Association of Wheat Growers, Ritzville, WA.