The effects of blue, green, and neutral density photoselective gels on the spectral quality of sunlight

Many researchers use neutral density black shade cloth to apply shade treatments that allow for the separation of confounding effects brought on by foliar shade (i.e. tree shade), such as water deficit due to competing vegetation, from plant responses to alterations in light quantity/quality. However, this black shade cloth does not alter spectral quality of sunlight like foliage does. Therefore, black shade cloths are not suitable for researchers looking to examine the effects altered spectral quality caused by foliar shade. Materials that selectively filter sunlight, like leaves, do exist and have been used to simulate foliar shade.