This exp eriment was carried out to find the method, in which some special phenomena accompanied with the aging of seed potatoes could easily be seen in the laboratory. As a result, it was proved that the stage of aging was determined by the state of sprouting, when examined in the dark.
The principal phenomena attracted the authors' attentions were the decrease of sprout growth, the death of apical part of sprout, and the tuberization at the end of sprout in early stage. The abnormalities, however, recoverd regularly by the treatment with a synthetic phytohormone, α-naphthaleneacetic acid, so that it may be supposed they occurred by the decrease of growth substance accompanied with the progress of aging.
In addition, the increase of sprouting, the loss of polarity, which had commonly been known as a sign of aged, became visible in a comparatively short period under the condition of darkness. Therefore, it may be very effective to determine the aging of seed potatoes to apply the method of examination in the dark above mentioned.