optimum adjustments of cereal combine harvester platform for canola harvesting by using of a simulated platform

in recent decades, canola has been considered as the most important oilseed. harvesting is the most major problem of canola cultivation, since canola pods are very sensitive to shocks and vibrations. large amount of produce will fall on the ground especially when the combine's head is not adjusted properly. when canola harvested with a combine, the losses may reach up to 50%. the yields can be improved by decreasing seed losses during the harvesting operation. the objective of this study was to determine the optimal harvesting conditions of combine platform to minimize grain losses. in order to achieve this, a laboratory test stand platform was designed and built in the department of mechanics of agricultural machinery in shiraz university. three factors which are more effective on the losses were assessed to determine the best adjustments. these factors were combine forward speed at three levels; 1.5, 2 and 2.5 km h-1, cutter bar speed at three levels; 800, 1100 and 1400 cycles per minute and the relative linear speed of reel in respect of forward speed also at three levels; 1, 1.3 and 1.5. desired experiment were accomplished on talaeie variety at 16% m.c) d.b(. the grain losses were measured at each level, with three replicates. by considering the interaction of factors, results showed that the effect of these factors at 5% level was significant, and the minimum loss occurred at 2 km h-1 for forward speed, 1400 cut per minute for cutter bar speed and 1.5 for relative reel speed to forward speed.