Phototermal induction of sugar beet plants

Abstract

This study was conducted to observe the combined effect of light and temperature on the flowering stage of sugar beet (Beta vulgaris L.) and to determine the minimum conditions of phototermal induction for several cultivars. Seed from twenty sugar beet cultivars were sown in pots containing sterilized soil and placed in growth chamber. During three weeks the pots were kept at 22°C degree of temperature under incandescent light (pre-induction period). After that, four plants of each cultivar were selected and submitted to cold treatment of 8.5°C with incandescent light for ten weeks. At the end of this period these plants continued to receive the same light treatment, but the temperature was increased to 25°C until the seed formation (post-induction treatment). From these results we concluded that through the phototermal induction is possible to verify the emition of seedstalks and flowering of sugar beet plants. Also it is possible to detect the requirements of light and temperature of different cultivars at the flowering stage.