The Effect of Drought and Vapour Pressure Deficit

Authors: Gucci Riccardo Massai Rossano Xiloyannis Cristos Flore James A

Publish Date: 1996/06/01

Volume: 77, Issue: 6, Pages: 605-613

PDF Link

Abstract

Riccardo Gucci Rossano Massai Cristos Xiloyannis James A Flore The Effect of Drought and Vapour Pressure Deficit on Gas Exchange of Young Kiwifruit Actinidia deliciosa var deliciosa Vines Annals of Botany Volume 77 Issue 6 June 1996 Pages 605–613 https//doiorg/101093/aob/776605To evaluate the effect of drought and vapour pressure deficit VPD on stomatal behaviour and gas exchange parameters young kiwifruit vines Actinidia deliciosa var deliciosa cv Hayward were exposed to alternating periods of drought and droughtrelief over two growing seasons Vines were grown either in the field or in containers Stomatal conductance of fullyexpanded leaves rapidly decreased as predawn leaf water potential was reduced below a threshold value of − 0·3 MPa Stomatal conductance reached minimum values of 10–20 mmol m −2 s −1 Transpiration rate was similarly sensitive to changes in leaf water status whereas more severe drought levels were necessary to affect photosynthesis significantly Net daily carbon gains were estimated at 4·7 and 2·7 g m −2 for irrigated and droughted vines respectively Gas exchange parameters recovered to values of irrigated vines within a few hours after relief of stress Rate of recovery depended on the level of stress reached during the previous drought period There was a steady decline in stomatal conductance when VPD was increased from 0·8 to 2·5 kPa in both irrigated and droughted vines The VPD at which stomatal conductance reached of 50 maximum values was 2·1–2·2 kPa for both treatments We conclude that stomata were highly sensitive to changes in soil water status and that midday depression of photosynthesis measured in kiwifruit vines was related to water deficits arising in the leaf because of both transpirational losses and to the direct effect of increasing VPD

Keywords: