Combined effects of drought and high temperature on gas exchange and growth of Malbec grapevines
Abstract
Drought and high temperature are important threats to plant growth and sustainable agriculture worldwide. Usually these two stresses occur together but quantifications of their combined effects on physiological responses of grapevines (Vitis spp.) are scarce. Our hypothesis was that water deficit, by reducing evaporative cooling, exacerbates heat damage to foliar function. A factorial experiment was conducted in a greenhouse with potted Malbec grapevines under two water regimes, well-watered and water deficit, and two temperature regimes, high and control temperature. Short-term stomatal regulation of photosynthesis was assessed by leaf gas exchange and stomatal conductance measurements. Results did not support our hypothesis. High temperature, peaking slightly above 45°C, did not compromise the photosynthetic machinery in leaves. On the contrary, in water deficit vines, high temperature increased photosynthesis, while in well-watered vines, high temperature increased stomatal conductance, photosynthesis, and transpiration. When water was not limiting, high temperature also increased leaf appearance and expansion rate, and whole-vine transpiration.
Issue: GiESCO 2017
Type: Extended abstract
Format: Poster
Authors
1 Estación Experimental Agropecuaria Mendoza. INTA. Mendoza. Argentina
2 Department of Horticulture. IAREC. Washington State University. Prosser, WA, USA
3 South Australian Research and Development Institute. Adelaide. Australia
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Keywords
climate change, heat wave, Vitis vinifera, water stress