Storage quality was evaluated for two tablestock potato (Solanum tuberosum L.) cultivars (‘Fabula’ and ‘Red LaSoda’) grown in a sub-tropical climate under three irrigation methods: seepage, surface drip, or sub-surface drip, and harvested over a three-week period after vine kill.

Tuber periderm maturation of both cultivars was a key determinant of tuber quality at harvest and during subsequent storage. Tubers harvested one week after vine kill were less mature, resulting in significantly higher weight loss and lower firmness after 14 days of storage, compared to later harvest times.

‘Fabula’ tubers harvested one week after vine kill were also compositionally less mature than those from the later harvests, as reflected by significantly higher losses in dry matter content and ascorbic acid content with increased storage time, irrespective of the irrigation method.

In contrast to ‘Fabula’, ‘Red LaSoda’ plants were compositionally more mature at harvest; dry matter content and ascorbic acid content remained constant during storage.

‘Fabula’ and ‘Red LaSoda’ tubers grown under drip irrigation had comparable harvest and storage quality to those grown under seepage irrigation when harvested two to three weeks after vine kill and stored at 10 °C, 80–85% RH.