Title: Increasing blue light from LEDs reduces leaf length in kale

Name: Boston Swan
Mentor: Bruce Bugbee
College: College of Agriculture and Applied Sciences

Department: Plants, Soils, and Climate



Hometown: Mendon, UT

Abstract:
Despite years of research, the effect of light quantity (intensity) and quality (color) on plants remains poorly understood. Light emitting diodes (LEDs) now facilitate this research because of their narrow band wavelength. Blue light (400-500 nm) has been known to reduce leaf expansion and petiole elongation in some crops (Cope and Bugbee, 2013; Cope et al, 2014; Snowden et al, 2016). Kale is one of seven vegetables in the species Brassica oleraceaand was chosen as a representative for the species because of its nutrient value. The system included 16 chambers; eight chambers at low Photosynthetic photon flux density, (PPFD; 200 µmol m2s-1) and eight at high PPFD (500 µmol m-2-1). The spectral distributions for each chamber are included below.

Whole plant fresh and dry mass decreased slightly with increasing blue light, but the effect was not statistically significant. We also found that leaf length decreased significantly with increasing blue light. Our data indicate that studies should focus on selecting wavelengths of light that enhance cell enlargement and the development of leaf area and radiation capture.