“…In many cases, non-linear equations have been used to explain the relationship between the two parameters better due to non-uniform distribution of chlorophyll and differential scattering and reflection of light at the wavelengths used (Markwell et al, 1995;Monge and Bugbee, 1992;Uddling et al, 2007). In this sense, several studies have reported that calibration should be speciesspecific (Castelli et al, 1996;Pinkard et al, 2006;Uddling et al, 2007;Yamamoto et al, 2002), and that it may even be affected by growing conditions (Campbell et al, 1990;Jifon et al, 2005). Another issue, although little addressed (Thompson et al, 1996), is that leaf structural parameters (LMA, tissue density, water content, etc.)…”