Performance optimization and knife dynamics of power tiller operated reaper during wheat harvesting

Mechanized harvesting is one of the components of agricultural mechanization used to overcome grain losses and enhance the production compared to the conventional harvesting. Power tiller operated reapers are quite effective for harvesting practices in small fields and especially in mountainous regions where the crops are grown on terraces. Compared to the tractor mount reaper and combine harvester, it saves fuel and cuts the maximum straw to produce the fodder of almost 4000 kg ha(-1) after the threshing operation. Thus, in case of wheat crop, it helps to save a significant energy of 1,524,000 kcal ha(-1) avoiding the environmental pollution by infield burn of the straw. However, un-optimized use of power tiller operated reaper may result in high maintenance cost, low efficiency and distress among the small land holding farmers. The main objective of this study was to quantify the optimum cutting knife dynamics by optimizing the performance parameters of power tiller operated reaper like cutting speed, operating speed, cutting index, field capacity and fuel consumption. A combination of forward speed at 2.82 km h(-1) and cutting speed at 3.42 km h(-1) with cutting index of 1.21 was found to be most effective for a minimum grain harvesting loss of 101.33 +/- 1.0 kg ha(-1) at a fuel consumption of 6.27 +/- 0.030 L ha(-1). A higher field efficiency of 71% was also recorded at cutting index of 1.21 for the same combination of forward and cutting speeds. Locus of cutter bar knife for the optimum combination of forward and cutting speeds helped to examine the operation of crank and cutter bar, prolonging the life of cutting mechanism. Thus, optimized performance of power tiller operated reaper will help to attain higher field efficiency at low fuel consumption and low maintenance.