Investigation of Combine Harvester Losses for Wheat in Qom Province

Wheat is one of the strategic crops that have been harvested in recent years by advanced combine harvesters. In this study, traditional combines were evaluated in terms of natural losses, head and back losses, field capacity, purity percentage and yield in field conditions in Qom (Iran). The total number of combine harvesters in this area was 110 out of which 20 samples with the experimental design of completely randomized design were selected. 35% of samples were New Holland Combine harvester TC5070, 30% John deer JD1055, 15% JD1165 and the remaining (20%) were New Holland TC5080, John deer JD955, JD1450 and Sampo 3065L. In terms of losses rates in different parts of the harvesters, 0.06% was related to the back of the machine and 1.35% of it was related to the head. The natural losses rates was 1.66% and total losses was 3.07% in this province. Three traditional combine harvesters (TC5070, JD1165 and JD1055) were compared statistically. The results showed that there was a significant difference between the harvesters in terms of field capacity at  5% level. The effective capacity of the TC5070, JD1165 and JD1055 combines was 1.23, 0.88 and 0.83 ha.h-1,respectively. According to the results, it is recommended to use JD1165 and TC5070 combine harvesters due to their low losses, acceptable purity percentage and suitable field capacity.