Field Performance Assessment of Self-propelled and Knapsack Power Rice Reapers, and Comparison with Manual Harvesting

In mechanized harvesting, it is very important to develop an appropriate rice reaper for decreasing costs and crop losses. In this study, the field performance of two rice reapers (self-propelled and knapsack power reapers) were compared with manual harvesting. The experiment was conducted in split-plot design with the rice varieties as the main factor in two levels (Hashemi and Khazar) and the harvesting method as sub-factor in three levels (three harvesting methods) based on randomized complete block design in three replications. The results revealed that the effective field capacity of a self-propelled reaper (0.237 ha.h-1) and knapsack power reaper (0.048 ha.h-1) was significantly higher than that of the manual harvesting (0.0083 ha.h-1). The time required for harvesting one hectare using the self-propelled reaper, knapsack power reaper and manual method were 4.22, 20.74 and 119.71 h, respectively. The labor requirements in harvesting for manual method were 159.7 man-h.ha-1 and those of the self-propelled and knapsack power reapers were determined 52.22 and 68.74 man-h.ha-1, respectively. The harvesting losses when self-propelled reaper and knapsack power reaper are used and manual method is practiced,  registered as 2.42% and 2.58 and 2.18 %, respectively. The net saving cost using self-propelled and knapsack power reapers were 7940728 and 4444297 Rial.ha-1 as compared to that of manual harvesting. The break-even point for knapsack power and self-propelled reapers were determined 2.00 and 11.42 ha.year-1, respectively.