Feasibility of Low-Cost Thermal Imaging for Monitoring Water Stress in Young and Mature Sweet Cherry Trees

Abstract

Infrared thermography has been introduced as an affordable tool for plant water status monitoring, especially in regions where water availability is the main limiting factor in agricultural production. This paper outlines the potential applications of low-cost thermal imaging devices to evaluate the water status of young and mature sweet cherry trees (Prunus avium L.) submitted to water stress. Two treatments per plot were assayed: (i) a control treatment irrigated to ensure non-limiting soil water conditions; and (ii) a water-stress treatment. The seasonal evolution of the temperature of the canopy (Tc) and the difference between Tc and air temperature (ΔT) were compared and three thermal indices were calculated: crop water stress index (CWSI), degrees above control treatment (DAC) and degrees above non-water-stressed baseline (DANS). Midday stem water potential (Ψstem) was used as the reference indicator of water stress and linear relationships of Tc, ΔT, CWSI, DAC and DANS with Ψstem were discussed in order to assess their sensitivity to quantify water stress. CWSI and DANS exhibited strong relationships with Ψstem and two regression lines to young and mature trees were found. The promising results obtained highlight that using low-cost infrared thermal devices can be used to determine the plant water status in sweet cherry trees.

Microtensiometers Accurately Measure Stem Water Potential in Woody Perennials

“…However, since Ψ stem have traditionally been discrete data, there has been extensive research to identify both direct and indirect assessments of plant water status. Thus, several attempts were made considering easily measured environmental variables such as VPD or air temperature and soil water content/potential [8,22,23], as well as non-destructive, discrete [24][25][26], and continuous [13,27,28] plant-based sensors and high-resolution imagery [29][30][31]. Although these research papers provided interesting results that relate with Ψ stem , they also emphasized the necessity of validating their results under different soil and climate conditions as well as under different cultivars.…”

Drought-Adaptive Mechanisms of Young Sweet Cherry Trees in Response to Withholding and Resuming Irrigation Cycles

“…Spain is the sixth-largest worldwide producer and the largest producer of fresh cherries in Europe [7]. Sweet cherry trees are characterized by their significant sensitivity to water stress during preharvest, when fruit growth may be penalized by water deficit [8][9][10]. Conversely, water deficit could be applied during the post-harvest period, after the flower differentiation period, when fruit quality or yield is little or not penalized by regulated water deficit [11].…”

Past and Future of Plant Stress Detection: An Overview From Remote Sensing to Positron Emission Tomography

“…However, its main applications is addressed toward the sensing for crop water-stress detection, for agricultural and phenotyping purposes: i.e., the setting-up of the irrigation schedules (Gutirrez et al, 2018 ), the identification of any anomalies in irrigation systems (Matese et al, 2018 ), as a part of Cloud of Things (CoT)-based automated irrigation network (Roopaei et al, 2017 ), as a powerful tool in plant breeding activities (Shakoor et al, 2017 ; Sagan et al, 2019 ; Siddiqui et al, 2019 ) and in ecological studies (Still et al, 2019 ). Many studies relied on thermography in both herbaceous (Mangus et al, 2016 ; Martynenko et al, 2016 ; Quebrajo et al, 2018 ) and arboreous (Egea et al, 2017 ; Espinoza et al, 2017 ; Santesteban et al, 2017 ; García-Tejero et al, 2018 ; Blaya-Ros et al, 2020 ; Gutiérrez-Gordillo et al, 2020 ) cropping systems. Consequently, a large variety of crop water-stress indices (CWSIs) have been developed both isolating the effect of the crop water status and normalizing the aggregated data at the canopy level (Poirier-Pocovi et al, 2020 ).…”