Measuring the Color of Growing Turf with a Reflectance Spectrophotometer1

Abstract
A single−beam spectrophotometer was used to measure the spectral reflectance properties of growing turf. From the data a two−wavelength reflectance ratio R745/R675 was developed for an objective index of turf color. This ratio changed from 3.0 for light green turf color to 6.5 for dark green turf color. (visual rating of 4 to 10, respectively). A two−filter instrument (Ratiospect) was used to measure this index on eight samples of turf of three species. A correlation of 0.984 was obtained between the Ratiospect readings and a visual score of turf color.