Effects of T5 fluorescent vs. LED (F3 Spectrum) vs. LED (X5 Spectrum)

Experiments were conducted in a vertical growing system on two lettuce varieties (Red Oakleaf and Green Butter Salanova) under three different light treatments – fluorescent T5 lighting, Illumitex F3 LED spectrum, and Illumitex X5 LED spectrum. Light intensity levels were matched for the three light treatments and all other environmental parameters (media, temperature, pH) were constant. Due to differences in spectrums, the weight of the lettuce plants, as well as the taste and feel, differed between the treatments. The results of this study show that with identical photon flux between light treatments, LEDs provide more “usable” photons while using significantly less energy to operate.

Introduction
The experiment described in this report can be compared to previously published experimental results using the same system. In a previous experiment, labeled “Experiment 1,” the watts were held constant between the light treatments; whereas in the experiment described in this report, “Experiment 2,” the photosynthetic photon flux density (PPFD, light intensity) was held constant. The red lettuce variety in the previous experiment, “Experiment 1,” was conducted with Salanova red oakleaf, which was also used in the current experiment. The results outlined in this report enhance previous in-house experimental data showing the benefits for LEDs in indoor farming for both operating cost savings as well as improved plant productivity. Additional reports and supplemental material are available from references [1-3].

Objective
To compare the effects of fluorescent lighting to two Illumitex Surexi power bar spectrums (F3 and X5) on growth of Salanova Lettuce (green butter and red oakleaf) with matching light intensity levels.

Click here to read the full whitepaper.