Abstract
Experiments were performed to check the course of stalonisation growth of the stolons and of the tuberisation in three experiments in which the plants of an early potato cv. Pierwiosnek grew under different conditions, including different lengths of the day. The following were inwestigated: the rate of stolon emergence, stolon growth, differences of the pattern of stolon growth, time-span of stolonisation and of tuber initiation, frequency of particular patterns of stolon growth in relation to the time of stolen emergence, intensity of terminal and laterel tuberisation, and of the branching of the stolons. The differences in the growth conditions in each of the three experiments enabled us to check the of variability of the particular features during the development of the stolons.