Physiology of the potato varieties and consequences for the grower

The physiology of the potato tuber is characterized by two consecutive periods: the dormancy and the incubation. During the dormancy period, the tuber is under vegetative rest and is unable to sprout. The incubation period begins at sprouting and ends when the first progeny tuber appears on the stolons. The duration of both periods varies depending on the variety. Varieties with a short dormancy period will be difficult to store, and varieties with a short incubation period will show a fast aging. An old tuber will emerge with difficulties and the yield will be low. In addition, some varieties are susceptible to desprouting, which accelerates tuber aging. Specific trials have been managed by Agroscope in order to characterize the physiology of the varieties listed in the 2015 Swiss list of recommended potato varieties. No link was found between the duration of the dormancy period, the duration of the incubation period, and the susceptibility to desprouting. The identified physiological characteristics of the varieties are presented in a summary table. This characterization is important in order to optimize the potato seed storage, identify the optimal duration of pre-sprouting, and guarantee a fast emergence and a rapid development of the plant. All these elements will contribute to high tuber yield.