The reflectance of a vegetation canopy is primarily determined by its leaf area index (LAI), the one sided leaf area per unit area of ground, which in turn is usually correlated to the concentration of chlorophyll (the total chlorophyll per unit area of ground) within the canopy|This laboratory experiment on the growth of curled cress Lepedium sativum (L), indicated that during moisture stress there was no correlation between chlorophyll concentration and LAI and therefore no correlation between chlorophyll concentration and canopy reflectance.