Losses as high as 20 bushels of corn per acre have been measured behind a poorly adjusted combine operating in weedy or severely lodged corn. Harvesting losses cannot be completely eliminated, but they can be reduced to 1 to 2 bushels per acre if you take time to check the performance of your combine. To keep harvesting losses low, you need to know here losses occur, how to measure them, what reasonable loss levels are, and what machine adjustments and operating practices will reduce losses. Calibrated loss monitors are useful in detecting separating and cleaning losses, but are unable to detect gathering unit losses. Gathering unit losses can be a major portion of machine loss.
Preharvest losses are ears that drop from the stalk before harvesting begins.
These losses are not causes by the combine, but they can be reduced by harvesting early. Harvesting losses can be separated into four types of losses. Gather losses occur at the front of the combine, and consists of ears missed or dropped by the machine and loose kernels shelled by the stalk rolls in the cornhead. Cylinder and separating losses will be found on the ground behind the combine. Cylinder losses are kernels attached to pieces of cob that were not shelled by the combine cylinder.