The presence of trichomes on a plant affect the plant’s ability to retain water; this, in turn, must affect light propagation and reflectance. It was hypothesized that a plant with a higher trichome density (Salvia leucophylla) would have a greater change in reflectance when exposed to a more aired or hydrated environment than a species with a lower trichome density (S. mellifera). Results obtained using a Unispec suggest that Salvia mellifera is more resistant to change in NDVI in response to drying and wetting. Water potential data suggest this may be related to the plant’s resistance to actual drying and wetting in the first place.
Schmitz, Logan A.; Mah-Ginn, Kolina; and Presthus, Hayley, "The Effects of Leaf Hydration on Light Reflectance in Salvia leucophylla and S. mellifera" (2013). Pepperdine University, Featured Research. Paper 65.