Potato bruise spot sensitivity dependence on regimes of cultivation

Potato tuber bruising was simulated by impact pendulum at temperature 7°C. Two varieties (Agria and Samantana) cultivated under five different regimes were tested one month and/or five months after harvest. The regimes of cultivation differ by fertilising and/or irrigation. The obtained black spots were measured carefully to obtain detailed shape and volume. The obtained results are discussed in relation to tuber anatomy (vascular ring), regime of cultivation and mean tuber density. It is shown that contrary to bruising in fruits the black spots had maximum diameter not close to the surface but close the vascular ring. The relation between spot volume and the mean tuber density seems to be variety dependent.