The performance of a forage chopper was tested using three adapted cutter blades namely, straight, triangular and V-shaped, at dif­ferent rotating speeds of the blades (500, 750, 1100 and 1300 r.p.m) and different forward speeds of the chopper (1.98, 2.7, 3.85, 5.15 and 6.5 km./h). Experiments were carried out at the experimental Sakha Agri. Res. Station, Kafr El-Sheikh Governorate, Egypt. Results indicated that the triangular type cutter blade (Tb) oper­ated at a rotating speed range from 750 to 1100 rpm and the forward speed range from 2.7 to 5.15 km/h may be considered as optimum op­erating conditions in the chopping process of cotton, corn and sunflower stalks. The corresponding fuel consumption values were 6.98, 5.80 and 5.93 L/h for cotton, corn and sunflower stalks respectively. the results also showed that the optimum total costs per unit area were 25.82, 24.15 and 24.84 LE/Fed.compared with 90.63 and 72 LE/Fed. for man­ual chopping cotton stalks, (corn or sunflower) crop stalks respectively.