INVESTIGATIONS ON DEVELOPMENT AND USE OF DODECATHEON-MEADIA L .3. EXOGENOUS FACTORS AND CHANGES IN ACTIVITY

No influence of daylength on temperature concerning changes in activit y can be shown under natural and simulated (Phytotron) conditions. Tem perature only modifies the length of growth period but neither long da y nor short day conditions prevent the transition to the rest period. There is no need of dry storage. Cold requirement of all resting organ s can be fulfilled directly at the beginning of the rest period. The q uality of resting organs is higher if plants are cultivated under cool er conditions. The plants survive dry periods in summer by the small r esting buds on fleshy roots.