drum was found. The movement of the crop in an axial direction was not continuous, with the crop often moving back axially in the direction of the feed section. Figure 4 shows that, as feed rate was increased, the capacity generally increased at 750, 950 and 1150 〖min〗^(-1) drum speeds for all threshing drums. The capacity of the rasp bar drum rapidly increased as the feed rate increased from 1000 to 4000 kg[head] h^(-1). From the above results, the best capacity (1038 kg h^(-1)) was recorded with the rasp bar drum at 3000 kg[head] h^(-1) feed rate and 750 〖min〗^(-1) (10.9 m s^(-1)) drum speed.