RESULTS AND DISCUSSION
Performance of modified spike took type wheat thresher was evaluated for threshing pigeonpea at three levels of feed rates and four levels of cylinder speeds. Mature sun-dried crop was fed to the thresher. Average values of threshing efficiency, cleaning efficiency, grain breakage and
non collectable losses were 99.51, 98.85, 0.99 and 0.62 per cent, respectively.
(a) Breakage: The effect of four levels of peripheral speeds and three levels of feed rates was studied on grain breakage (Table 4). Average grain breakage was 0.99 per cent. Factors means (Table 5) clearly indicated that breakage was directly related to the cylinder peripheral speed and inversely related to crop feed rate. In other words, the increase in the peripheral speed increased breakage of grains and breakage of grains decreased with increase in feed rate. The effect of peripheral speed and feed rate was significant at 5 per cent level of confidence (Table 5 and 6). However, the effect of feed rate on breakage and their interaction was non-significant. The per cent breakage ranged from 0.64 to 1.32. The minimum breakage of 0.64 per cent was observed at lower peripheral speed (PS1) and higher feed rate (1000 kg/h), while breakage was the maximum at higher peripheral speed (PS4) and lower feed rate (700 kg/h). Breakage was found to be higher at higher peripheral speed due to higher combined effect of impact and rubbing force