Weed Growth in Response to Greenhouse Supplemental Lighting

Publisher Website
Google Scholar
Abstract
Studies were conducted to compare weed growth under lighting systems composed of metal halide (MH) lamps and fluorescent-incandescent (FI) lamps. The MH lamps provided more light intensity and over a 6-week period caused plant dry weight to be 60 to 70% more than for plants exposed to the FI lamps. One week after emergence, all plants under the higher intensity MH lamps had larger stems and cotyledons or first true leaves. Six weeks after planting, weeds grown under the MH lamps had larger leaves, shorter internodes, thicker stems, and, in general, more pubescence than plants under the conventional lighting system. Growth habits of weeds exposed to the MH lamps were similar to those observed for field growth plants.