Introduction. Optimising agricultural water use implies the
combination of physiological, technological and engineering techniques, especially those
for continuously monitoring the water status of plants subjected to deficit irrigation. A
methodology to estimate water stress of young almond trees from thermal images was
developed based on assessing the physiological status of almond crops under limited
water-supply conditions. Materials and methods. Two irrigation treatments
were tested during the maximum evapotranspirative demand period (214th to the 243rd day of
the year) in an experimental almond [Prunus dulcis (Mill) D.A. Webb, cv.
Guara] orchard: a low-frequency deficit irrigation (LFDI) treatment, irrigated according
to the plant-water status, and a fully irrigated treatment (C100) at 100% of crop
evapotranspiration. Daily canopy temperature at midday (TC) was measured with an infrared
camera, together with standard measurements of stem-water potential (ΨStem) and stomatal
conductance (gS). The time course of these parameters and their relationships were
analysed. Results and discussion. The time course of the parameters studied
showed highly significant correlations among the differentials of canopy-air temperature
(ΔT), ΨStem and gS. The methodological protocol for analysing thermal images allowed a
time saving in processing information and additionally offered the possibility of
estimating the ΨStem and gS values. Conclusion. Our results confirm that
infrared thermography is a suitable technique for assessing the crop-water status and can
be used as an important step towards automated plant-water stress management in almond
orchards.