Field studies, on the effect of various degrees of plant water stress on diurnal variations in leaf water potential (ψL) and stomatal conductance of wheat revealed that ψL decreased during the day upto 1300 hours, remained static between 1300 and 1500 hours and increased thereafter. Stomatal conductance firstly increased upto 1100 hours then decreased till 1300 hours, increased there after till 1500 hours and started again decreasing from 1500 hours attaining a minimum at 1900 hours. Higher ψL and stomatal conductance was recorded in no-stress treatment as compared to -1.5 MPa stress.
