Pulsed Thermography as a Reliable Tool to Detect Presymptomatic Stages of Botrytis cinerea Infection in Plants

Timely and noninvasive detection of plant diseases may help to mitigate significant yield losses and represents an important milestone in sustainable plant protection. Herein, we report the application of pulsed thermography (PT) to predict presymptomatic stages of gray mold. For this purpose, pepper and tomato plants were inoculated with conidia of Botrytis cinerea or Trichoderma harzianum, a beneficial fungus employed as nonpathogenic control. Time-course measurements on infected leaves showed that, unlike classical passive thermography, PT revealed thermal patterns within a few hours after inoculation, much earlier than the appearance of necrotic lesions caused by B. cinerea. Diagnostic parameters together with physiological and molecular analyses confirmed a high reliability of PT in the early detection of B. cinerea infection. Collectively, our data demonstrate that PT imaging is a valid and reliable tool for the early and noninvasive detection of B. cinerea infection and opens new paths for sustainable and precise agriculture.