Plants respond to drought with a restriction of leaf and root growth. The study aimed at analysing the morphological and functional adaptation mechanisms of Beta and Cichorium storage root and leaf forms to limited water supply. Two pot experiments were conducted: 1) with sugar beet, swiss chard, root and leaf chicory at 100%, 50%, and 30% water supply, 2) with sugar beet, fodder beet and swiss chard at 100% and 30% water supply. The results indicate that there is no general response mechanism of root and leaf forms to better sustain drought stress. Sugar beet adapted to limited water supply with a marked decrease of the storage root to leaf ratio, indicating in particular a restriction of the predominant sink, while maintaining a very low transpiration coefficient. In contrast, swiss chard, root and leaf chicory kept their storage root to leaf ratio almost constant while adapting the transpiration coefficient. Sucrose storage was inversely related to the accumulation of solutes in the storage root of sugar beet and fodder beet. There is some evidence that the formation of a storage root in sugar beet and root chicory is inhibited by the inability of the plants to establish new sink capacities under drought conditions.