Effective Parameters on Mechanical Damages of Potato During Mechanized Harvesting

The effects of soil moisture content, forward speed and operation depth during harvesting by a potato digger (without conveyor shaker) on tubers quantitative and qualitative damages were studied and the optimum conditions were determined for treatments. The experiments were arranged as a strip split plot test based on complete block design with three factors and three replications. Mechanical damage rates of potatoes due to mechanized and traditional (manual) harvesting methods were compared by t-test. Buried tubers rate (quantitative loss) was increased with increasing of forward speed especially in wet soil probably due to the excessive soil transferred to the conveyor. Peeled tubers rate was reduced by increasing forward speed to 3 km/h in soils with low moisture content. The optimum conditions for mechanized potato harvesting with minimal quantitative loss and damage rate to product quality obtained at soil moisture of 10-15% db (40-60% Field Capacity) and 2-3 km/h forward speed. The cutting damage of tubers in traditional harvesting method was more than mechanized one, while the peeling damage rate was less. Generally, external damage rate of tubers in traditional method was significantly more than that obtained from mechanized method.