Effect of Light Quality on the Growth and Growth-substance Content of Plants

Abstract

The main effect of incandescent light on most of several species and varieties of plants grown in cabinets illuminated by fluorescent light was to increase the length of internodes. Although leaf area was little affected, incandescent light increased the dry weight of most plants. In dwarf French bean plants, the longer internodes of plants grown with additional incandescent light was associated with, and perhaps a result of, the higher content of gibberellic acid-like and indolylacetic acid-like growth substances.