Department of Agronomy, Haryana Agricultural University, Hisar-125004
An experiment comprised of three levels of water stress, -0.5, -1.0 and 1.5 MPa mid day xylem water potential and no water stress (control) treatment, was conducted to study the effect of water stress on water use and water-use efficiency of dwarf wheat during two consecutive rabi seasons of 1977–78 and 1978–79. Water extraction pattern and water use varied markedly with water stress. The maximum extraction of available soil water was found from 0–30 cm soil depth being highest with no water stress treatment. The per cent extraction of available soil water from this layer decreased with increase in the magnitude of water stress particularly during jointing to flowering stage. Most of available water (89–93 per cent) was used from the upper 90 cm soil depth. The water use was higher with no water stress treatment and decreased considerably with severe water stress (−1.5 MP a) imposed during jointing to flowering. Maximum grain yield 52000 kg/ha and water-use efficiency (13.9 kg/ha mm) was found with no water stress treatment. The greatest adverse effect of water stress on grain yield and water-use efficiency was observed during planting to jointing stage.
