|MadSci Network: Botany|
First, the term "artificial light" is a misnomer. The more accurate term is electric light. Incandescent lamps by themselves are too hot and are inefficient so produce relatively little light. Thus, by themselves, incandescent bulbs are not good light sources for plants. Fluorescent lamps are much cooler and much more efficient so are a good light source for plants except that they cannot provide as much light as full sunlight. High intensity discharge lamps, such as high pressure sodium, do provide light levels as high as natural sunlight. Generally sunlight is better because it is typically easier to provide the high light levels most plants prefer with sunlight than with electric light. One exception would be in winter in a greenhouse where natural sunlight levels may be very low and electric lights, even fluorescent lamps, could provide much more light and much more rapid growth. Plants that grow well in low light such as most foliage house plants and African violets often grow as well or better with electric light than they with natural sunlight, which varies widely from day to day and season to season.
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