Light Culture of Chrysanthemum under Feeble Incandescent Lamps.

In order to find out if the feeble incandescent light can delay the flower bud differentiation of chrysanthemum lighted by such lamps as 10, 20, 30 and 60-watts, the following experiment was carried out in 1960. 1. The materials were cut on May 11, planted in pots on June 22, and has produced three branches by pinching. Pots were placed on the bench in the greenhouse, and lighting started on August 5, stopped on September 20. 2. Any distinct difference in elongation of stem was not found among those in differently lighted sections. However in the feeble light sections they had a little higher elongation than in the other sections and the standard sections. 3. The flowering was delayed in proportion as the light intensity increases. The sections lighted by 60 and 30-watt lamps showed almost similar flowering, but in the 10-watt lamp section the flowering was earlier than in the others and flowered for a longer period of time. 4. As to the flower bud formation, a considerable number of flower buds in 10-watt lamp section appeared first, and 20 and 30-watt lamp sections followed. 5. Consequently, the limit of light intensity in light culture of chrysanthemum seems to be 30-watts per square 3.3 meter of a bench.