The performance of a new mechanical weeder was investigated. Each unit of the machine considered of a four bar mechanism. effect of vehicle and rotational speeds of the machine on the performance of the system and mechanical damage were studied in four levels of speeds. Experiments were done at vehicle speed of 1.27, 2.1, 3.5 km/hr and rotational speed of 70, 93, 134 and 184 rpm in a corn field which the plants were at the 8-10 leaf stage. the results showed that the effect rotational speed on the performance of the machine and mechanical damage of the plants was considerably compared that the vehicle speed. the vehicle speed of 5.4 km/hr and rotational speed of 134 rpm were found as the optimal speed for cultivation by this machine, considering the maximum performance of the system and minimum damage of the plants.
