My thoughts are that since fluorescent bulbs were relatively new in 1957, that any advice given out about fluorescent lights in conjunction with growing or flowering ought to be discarded. Bulbs and coatings-even in incandescent bulbs-have come SO far from 1957, that to rely on any info from that era is to sell one's self short.

Sam

The information is correct as far as it goes. Light at the bluer end of the photosynthetic range is good for general plant growth while light at the red end is better for flowering and fruiting of plants. Modern fluorescents provide light of both types in various combinations. You will see references such as cool white (bluer), warm white (redder), or a temperature like 3000K (warm/red) or 6500K (cool/blue). All are good for plants. Incandescents are simply too hot and too inefficient to be used today.