High-resolution aerial thermal imagery for plant water status assessment in vineyards using a multicopter-RPAS

Climate change models predict that Mediterranean region, where the most important wine-producer countries worldwide are present, will experience increased frequency and severity of drought periods. Consequently, there is an increased requirement for improvement in the irrigation assessment of vineyards. It was described that grapevine water status can be determined as a function of stomatal conductance (g(s)), with values of this parameter below 100 mmol H(2)0 m(-2) s(-1) indicating that grapevines are under drought. Stomatal conductance is a physiological parameter that can also be estimated remotely by correlation with canopy temperatures. Therefore, remote thermal sensing of gs can then be used to develop an irrigation scheduling based on physiological plant status of drought stress. Multicopter RPA (Remote Piloted Aircraft) combined with aerial thermographic imagery open a new opportunity for water stress detection in vineyards. High-resolution thermal images acquired from the multicopter were used to generate three different thermal indexes and three basic alternative methods developed from leaf energy balance equation to correlate with gs. The use of this technology for irrigation assessment in vineyards is discussed.