Utilization of potatoes for life support systems in space. III - Productivity at successive harvest dates under 12-h and 24-h photoperiods

Efficient crop production for controlled ecological life support systems requires near-optimal growing conditions with harvests taken when production per unit area per unit time is maximum. This maximum for potato was determined using data on Norland plants which were grown in walk-in growth rooms under 12-h and 24-h photoperiods at 16 C. Results show that high tuber production can be obtained from potatoes grown under a continuous light regime. The dry weights (dwt) of tuber and of the entire plants were found to increase under both photoperiods until the final harvest date (148 days), reaching 5732 g tuber dwt and 704 g total dwt under 12-h, and 791 g tuber dwt and 972 g total dwt under 24-h.