Joseph Meehan wrote:

The best most even light is in the center 20 inches. Remember that
fluorescent lamps are not always the best single source of light. It
depends on the plant etc. Most of the time you would be better served by
using a mix of fluorescent and incandescent light.

My 48" fixtures have never failed to produce robust transplants, rivalling
anything I've seen at the local garden store. Prob is, 48" racks have a
large footprint. Easier to fit a 24" stand in the kitchen.