The growth and flowering of Hyacinthus orientalis L. Forced in pots under fluorescent light of different colours

Abstract

Three hyacinth cultivars were forced under fluorescent lamps which emitted white, blue, green, yellow and red light. The plants started flowering in the first decade of February. The forcing period for two cultivars, 'Anna Marie' and 'Blue Star', was shortest under lamps emitting red light. The cultivar 'White Pearl' flowered equally early under lamps emitting red, white and blue light. The impact of light colour (wavelength) on the leaf greenness index (SPAD) was demonstrated. The photosynthetic activity of leaves was dependent on the cultivar. It was related both to the net rate of photosynthesis and the photosynthetic efficiency. Specific leaf area (SLA) also depended on the cultivar. The level of SLA was related to the rate of photosynthesis and its efficiency. SLA was highest in all cultivars under green and yellow colour light. The chlorophyll content in the fresh and dry weight of leaves was highest under yellow light lamps.