Temperature influences the ability of tall fescue to control transpiration in response to atmospheric vapour pressure deficit

Abstract

Water availability for turfgrass systems is often limited and is likely to become more so in the future. Here, we conducted experiments that examined the ability of tall fescue (Festuca arundinacea Schreb.) to control transpiration with increasing vapour pressure deficit (VPD) and determined whether control was influenced by temperature. The first study was under steady-state conditions at two temperatures (21 and 27 C) and two VPDs (1.2 and 1.8 kPa). At the lower temperature, water use was similar at both VPDs, indicating a restriction of transpiration at high VPD. At 27 C, transpiration control at high VPD was weakened and root growth also declined; both responses increase susceptibility to water-deficit stress. Another series of experiments was used to examine the physiological stability of the transpiration control. Temperature and VPD were adjusted in a stepwise manner and transpiration measured across a range of VPD in the days following environmental shifts. Results indicated that VPD control acclimated to the growth environment, with adjustment to drier conditions becoming evident after~1 week. Control was again more effective at cool than at hot temperatures. Collectively, the results indicate that transpiration control by this cool season grass is most effective in the temperature range where it is best adapted.

Stomatal acclimation to vapour pressure deficit doubles transpiration of small tree seedlings with warming

“…), and the strength of the acclimation response can depend on growth T (Sermons et al . ). Despite these reports, ecosystem and global models still rely on expectations based on the well‐known relationship between g s and VPD described by Oren et al .…”

“…Other studies document stomatal acclimation to VPD that maintains homeostasis of water status (Nejad & van Meeteren ; Sermons et al . ; Will et al . ; Carins Murphy et al .…”

Water: the most important ‘molecular’ component of water stress tolerance research

“…Therefore, even under the short-term time frame of stomatal aperture control, both hydraulic and chemical signalling are likely to be intertwined. Second, the long-term control of leaf water loss via the control of leaf development is under both biochemical and hydraulic control; however, it is becoming increasingly clear that the long-term growth environment eventually conditions a short-term leaf conductance response to VPD (Sermons et al 2012;Schoppach and Sadok 2013).…”

Limited transpiration under high vapor pressure deficits of creeping bentgrass by application of Daconil-Action®

“…have revealed the presence of the limited-transpiration trait under high VPD similar to those with the crop species (Sermons et al 2012). In experiments where VPD was increased step-wise at an optimal temperature of 21°C, expression of a limited-transpiration response occurred at 1.45 kPa and little additional transpiration rate increase occurred at higher VPD, indicating stomatal conductance control.…”

“…Furthermore, statistical analyses failed to find a clear relationship with field temperatures, and all transpiration measurements were made at 32°C, a temperature much higher than the optimal growth range for this coolseason turfgrass. It is conceivable that breakpoints were being influenced by other components in the management programs (e.g., nutrition) or, perhaps, plant acclimation to other environmental signals (Sermons et al 2012). We also cannot know how long the transpiration control persists after Daconil-Action is applied.…”