Growth and Subsequent Yield of Tomatoes following End-of-day Light Treatment of Transplants

Abstract

The influence of end-of-day (EOD) light treatments of tomato (Lycopersicon esculentum Mill. cv. Mountain Pride) transplants on growth and subsequent fruit production was investigated. In the first experiment, transplants were treated with EOD red (R) and far-red (FR) light for 2 weeks in a controlled environment and then placed in the greenhouse under ambient light conditions from November to March. Before transplanting to the greenhouse, transplants treated with EOD R light were shorter and had less total leaf length than plants that were not treated with EOD light (controls). EOD R light increased the number of flowers on the plants before first harvest but had no effect on subsequent fruit production (as compared to plants treated with EOD FR light or control plants). In the second experiment, cool-white fluorescent lights (a light source high in red wavebands) were used to supplement solar light that transplants received in a nonshaded glasshouse for 1 hour before the end of the natural photoperiod. The fluorescent light reduced transplant height and total leaf length as compared to plants not treated with supplemental light. Supplemental fluorescent light for transplants had no effect on subsequent fruit production in the field. These results suggest that EOD light treatments that affect tomato transplant growth do not affect subsequent fruit production.