Optical properties of vegetable matter and associated analytical techniques such as VIS and NIR reflectance spectroscopy were used for several decades in the foodstuff industry. By means of these techniques, is possible to study and determine the plant pathology of crops: health or disease conditions, water stress, growth, etc., being a good alternative to traditional chemical or biological tests, generally very invasive and even destructive. The aim of this work is to analyse and quantify the effect of the presence and development of the pathogen Fusarium on spectral signatures of Burley tobacco leaves, and to evaluate the potential of radiometric techniques as tools for diagnosis.