Sviluppo di tecnologie remote e prossimali di monitoraggio ottico per la mappatura delle condizioni di stress idrico in vigneto, basate su droni e strumenti ICT

In recent years, optical sensing techniques have been widely spread since they allow the non-invasive evaluation of water stress in a timely fashion. The experimentation, carried out in two vineyards located in Usini and Arzachena (Sardinia, Italy), consisted of four treatments: i) two irrigation treatments applied according to specific leaf water potential thresholds (HIGH and LOW); ii) two reference irrigation treatments (DRY, no irrigation, and WET, irrigation at field capacity). An experimental campaign using the Mikrokopter Okto drone took place on August 2015. The drone was equipped with multispectral and thermal cameras. Since the canopy temperature is an indicator of water stress, crop water stress index (CWSI) values were calculated as the temperature differences between the canopies of the LOW and HIGH treatments and the canopies of the reference treatments. In addition, an automated digital imaging system collected high-resolution vegetation images at daily intervals and the changes in plant colour coordinates (RGB) due to changes in vine phenological stage and water status were detected. The indices obtained from optical sensing observations were then compared with stem water potential, photosynthesis, and fluorescence measurements.