Early Induction of Floweing in Sugarbeets 1

Sugarbeets ( Beta vulgaris L.) are biennial and under natural conditions flower during the 2nd year of growth. Early induction of flowering and maturation of seeds under controlled conditions could accelerate sugarbeet improvement through breeding. Several cultivars were grown in controlled environment chambers starting at various ages. Floral stalks developed after as little as 30 days growth from seed in a particular growth chamber (No. 3) with a 14/10 hr, 22/14 C light‐dark temperature regime. Plants in other chambers with the same light and temperature program did not respond as early. Floral induction in seedlings was also achieved in a continuously lighted growth chamber. Not all sugarbeet lines gave the early reproductive response. The response was earlier and more complete with young, rapidly growing plants. Plants that had been started 59 days before being placed in Chamber 3 did not give a reproductive response. An annual line of sugarbeets did not flower as early or completely as some of the biennial lines in Chamber 3. Further research is needed to define the conditions required for reliable control of sugarbeet floral induction in growth chambers. Rapid floral induction will permit up to five generations a year instead of the two‐generation advances presently feasible.