Potato tuber water potential components during storage

Abstract

Measurements of the water potential components in stored potato tubers were made over two storage seasons. Total potential at harvest was about −0.3 MPa and decreased to −0.5 to −0.6 MPa over the first 5 to 7 weeks of storage. During the remaining 25 weeks of storage the potential decreased another 0.1 MPa. Increases in osmotic pressure of about 0.1 MPa occurred during the first 5 to 7 weeks and turgor pressure decreased about 0.2 MPa, after which both were nearly steady. The small changes in osmotic pressure were correlated with changes in total sugars.