Light and shade: the effect of sunlight and artificial light on photosynthesis and yield in strawberry

A review was conducted to determine the effect of irradiance on photosynthesis and yield in strawberry under sunlight, artificial light or a mixture of both. The mean photosynthetic photon flux density (PPFD) (± standard deviation (s.d.)) for the saturation of CO2 assimilation was 1016 ± 419 µmol/m2/s (n = 74). Plants had similar photosynthesis when exposed to white, red, green, blue, or red + blue light (p > 0.05, n = 6 to 14). Yields in increased in a linear pattern up to 60% to 85% of full sun conditions (p < 0.001, R2 = 0.72). Shaded plants had mean light levels of 49.4 ± 16.6% of the controls and 67.8 ± 17.1% of the yields (p < 0.001, R2 = 0.58, n = 37). Yields in greenhouses with supplementary lighting were 1.51 ± 0.54 times those without supplementary lighting (p < 0.001, n = 37). Plants had similar yields with white, red, blue, or red + blue light (p > 0.05, n = 6 to 12). Information is required to determine the best light conditions for plants under artificial light. Research is required to determine whether shade can reduce the impacts of global warming on yields in warm locations.