Shape of bruise spots in impacted potatoes

Potato tuber bruising was simulated by an impact pendulum at a temperature of 7 °C. Two cultivars (“Agria” and “Samantana”) cultivated under five different regimes were tested 1 month and/or 5 months after harvest. The regimes of cultivation differed by fertiliser use and/or irrigation. The black spots obtained were measured carefully to obtain detailed shape and volume data. The results are discussed in relation to tuber anatomy (vascular ring), and it is shown that both shape and volume details of the bruise spots can be described successfully by polynomial of the third order.