Effect of Temperature Variation and Blue and Red LEDs on the Elongation of Arugula and Mustard Microgreens

Recent studies using LED lighting at low to modest intensity have indicated that compared with red light, blue light can promote plant elongation in many crops as a shade avoidance response despite varying sensitivity environments, species, and growth stages. Currently, there is limited understanding of how temperature affects the light-mediated response. To clarify this point, two microgreen species (arugula mustard) were grown indoors under quality × treatments: (peak 670 nm) 450 18 °C or 28 °C. A photosynthetic photon flux density 110 µmol m−2 s−1 photoperiod 12 h d−1 used for all treatments. After 6 8 days treatment, both temperatures, vs. promoted elongation, demonstrated by greater rate, final height, hypocotyl length, arugula but not mustard. Blue also some shade-avoidance responses such decreased cotyledon size increased petiole length dry mass partitioning hypocotyls only. The promotion was than °C, showing interactions between on most traits. For mustard, independent no These results suggest reversed high temperature, temperatures species.