Cultivation of the potted plants Schefflera and Anthurium under electrochromic glass : Smart materials crop experiments

Summary

Anthurium and Scheffl era are high-value ornamental crops requiring low sunlight levels, preferably of diffuse nature. This is achieved by shading screens, temporary coatings and combinations of both. Electrochromic glass able to regulate light transmission or diffusion could allow higher light sum than traditional shading without exceeding light damage thresholds, leading to improved crop growth. Two small-scale experiments were conducted simultaneously to evaluate the possibilities of EC Glass to be used as greenhouse cover for these crops. Two types of electrochromic glass where used: a darkening EC glass for anthurium; a diffusing EC glass for Scheffl era. The EC Glasses were compared to a reference fl oat glass with a temporary coating. Darkening EC Glass gave very good control of the light conditions: higher light sum by more constant light, less peaks on sunny days and more light on clouded days. However, this did not translate in faster growth, more fl owers or better plant quality. The achieved light advantage by the glass was counteracted by high leaf temperatures that lead to stomata closure and lower photosynthesis effi ciency during sunny periods. Diffusing EC Glass gave also good control of the light conditions as programmed: diffuse light whenever the set threshold was reached. The diffusive state lead to a slightly lower light sum than the reference coated glass. However, the changing diffusion conditions did not result in faster growth, nor better plant quality: the plants from the Diffusing Glass treatments remained shorter and had a lower leaf area than the constantly diffuse reference.