New CIMMYT Publications: The normalized difference vegetation index (NDVI) Greenseeker TM Handheld sensor – Toward the integrated evaluation of crop management — Part A — Concepts and case studies
A. Plant reflectance and normalized difference vegetation index (NDVI)
Reflectance is the ratio of energy that is reflected from an object to the energy incident on the object. Spectral reflectance of a crop differs considerably in the near infrared region (λ = 700-1300 nm) and in the visible red range (λ = 550-700 nm) of the electromagnetic spectrum.