The present study analyzed the differences in potatoes harvested during two cropping periods, namely "fall" and "spring", in Nagashima, Kagoshima Prefecture. Specifically, tuber size, weight, hardness, approximate mineral composition, and ascorbic acid content were measured. There were no differences in potato size, weight, ascorbic acid content, and hardness between the two harvest periods. However, moisture, sodium, and calcium content of fall potatoes were higher. Indeed, differences in the quality and taste of the potatoes between the fall and spring potatoes have been widely acknowledged by local consumers since long. The moisture and calcium content of potatoes varied with changes in transpiration. The lower calcium content of spring potatoes than that of fall potatoes led to the development of internal brown spots, hollow heart, and bruising in the former. We hypothesized that the higher moisture and calcium content of fall potatoes is related to their higher water absorption in this period. Additional factors such as mean temperature may also shape the differences between the two cropping periods.
