BEHAVIOR OF OBSERVED AGROMETEOROLOGICAL STRESS INDEXES WITH SOIL-WATER AVAILABILITY IN WHEAT TRITICUM-AESTIVUM)

A field experiment conducted during the winters of 1990-91 and 1991-92 on wheat (Triticum aestivum L. emend. Fiori & Paol.) with 5 dates of sowing under 3 moisture levels showed differences in behaviour of predawn leaf-water potential, canopy temperature, stomatal resistance and transpiration rate with soil-moisture availability in the crop. Due to interdependence between these stress parameters either predawn leaf-water potential or stomatal resistance may be used for internal moisture status of the plant and either canopy temperature or transpiration rate may also be used for the influence of external atmosphere condition on the plant for soil-plant-atmospheric relations. Response functions were developed to understand the behaviour of these indices of different levels of soil moisture in wheat.