Een onderzoek naar de factoren, die ontijdige knolvorming bij vroege aardappels bepalen

Premature formation of tubers ('submarines') is a disturbance in the normal growth of a planted seed potato, resulting in the formation of some small daughter tubers without any aerial growth. In certain years losses may be heavy. The main cause is the formation of sprouts during storage which have to be removed. All factors preventing or reducing such sprout formation favour normal development: especially low temperature (above freezing-point) and light during storage, also late lifting of the seed tubers, large tubers, planting at higher temperature and in moist soil.

The underlying process of premature tuber formation was assumed to be loss of water by removal of sprouts during storage, resulting in an increase in the concentration of solutes. Essentially the same occurs with normal tuber formation but there by an increase in assimilates. This concept was supported by plasmolysis studies in the hairs of the sprouts.