amount of CO 2 diffusing through stomata into the leaves, thus slowing down carbon fixation. Limitation of g S (thereby increased leaf stomatal resistance to transpirational water loss) could be one of the reasons that plants had lower E when grown in
in a vice. The ψ s of the sap was measured at 20 °C by psychrometers (C-52 sample chambers; Wescor, Logan, UT). Values of ψ s were averages of two measurements from each sample. Leaf turgor pressure (ψ p ) was calculated as the difference between ψ
The P-V curve has been used to estimate symplastic water volume, ψ S , pressure potential, turgor loss point, and elastic modulus of plant cells, tissue, and organs ( Holbrook and Sinclair, 1992 ; Richter, 1978 ; Scholander et al., 1965 ; Tyree
-RWC tlp ), where ε is expressed in MPa, Ψ os is the ψ S at full turgor (MPa), and RWC tlp is the relative water content at the turgor loss point. Pressure–volume curves were obtained before the application of water stress in the first week of June
flood-irrigated pecans Agr. Water Mgt. 69 179 190 Shackel, K.A. Brinckmann, E. 1985 In situ measurement of epidermal cell turgor, leaf water potential, and gas exchange in Tradescantia virginiana L Plant Physiol. 78 66 70 Stein, L.A. McEachern, G
browning of tissues ( Figs. 2 and 3 ). KBG appeared to reduce ψ leaf more than TF, suggesting that it can extract soil water at lower contents in the top layers to the point of triggering the feed-forward stomatal closure cascade. At that point, the
, the WUE-used showed the trend: T2 > T1 and T4 > T3, indicating an improvement in WUE with a higher slab-EC set point. Gas exchange. In general, there was a highly significant positive correlation between leaf photosynthesis and transpiration
0.15 L·L −1 or less. Reduced leaf expansion is an easily observed symptom of water stress, because turgor pressure is the driving force for cell elongation ( Taiz and Zeiger, 2010 ). Turgor pressure, in turn, typically decreases with decreasing
( Zwack and Graves, 1998 ). We noticed that predawn leaf water potentials decreased rapidly with substrate moisture content after the moisture content decreased to a critical point. This critical substrate moisture content seemed to be around 15% for all
from the plant to the environment through transpiration and a simultaneous increase in stomatal density, which contributes to the balance of gas exchanges ( Batista et al., 2010 ). This property can compensate for the leaf area loss that is commonly