Search

Evaluation of the Penman-Monteith-based crop water stress index (CWSI), as a potential indicator of turf irrigation timing, requires reliable estimates of potential (minimum) canopy resistance, r cp , and aerodynamic resistance, r a . This paper compare various methods of estimating r cp and r a for evaluation of water stress of bermudagrass turfgrass (Cynodon dactylon cv. Midiron) in the desert Southwest of the USA. First, two empirical CWSI models were developed using field data collected from well-watered and severely water-stressed turf plots during the 1986 growing season in Tucson, AZ [...]

A field study assessed the accuracy and consistency of crop water stress index (CWSI) estimates determined by two empirical models and one theoretical model for evaluation of bermudagrass [Cynodon dactylon (L.) Pers. cv. Midiron] water status. The simplest empirical model, describing canopy temperature minus air temperature (T c − T a ) of well-watered turf as a linear function of air vapor pressure deficit, was inadequate for estimating CWSI, since seasonal averages of CWSI for well-watered, moderately stressed, and stressed turf had corresponding coefficients of variation of 1170, 160, and 86, respectively [...]

Development of portable infrared thermometers and the definition of the Crop Water Stress Index (CWSI) have led to widespread interest in infrared thermometry to monitor water stress and schedule irrigations. But the CWSI concept is still new and poorly understood by many. The purpose of this paper is to review the definition of CWSI, and the determination and interpretation of the non-water-stressed baselines used to compute CWSI. The non-water-stressed baseline equation normalizes the canopy minus air temperature differential for variations in vapor pressure deficit (...)

Infrared thermometry can be a valuable research and production tool for detecting and quantifying water stress in plants, as shown by a large volume of published research. Users of infrared thermometers (IRT) should be aware of the many equipment, environmental, and plant factors influencing canopy temperature measured by an IRT. The purpose of this paper is to describe factors influencing measured plant temperature, outline sampling procedures that will produce reliable Crop Water Stress Index (CWSI) values, and offer interpretations of CWSI and plant temperatures relative to crop production and other water stress parameters by reviewing previously conducted research (...)

Degagement des limites superieures de Tf-Ta (temperature du feuillage, temperature de l'air ambiant) derivees selon Idso etal. et mesurees au champ. Effets de divers facteurs de milieu, principalement la vitesse du vent sur les limites inferieures et superieures de Tf-Ta et de l'indice de contrainte hydrique de la culture (CSWI). Comparaison du potentiel hydrique foliaire, de Tf-Ta et du CSWI dans des cultures (sorgho, mais, haricots, cotonniers)