DIURNAL CHANGES IN VINE WATER STATUS AND GAS EXCHANGE PARAMETERS OF VITIS VINIFERA L. CV. TEMPRANILLO GRAPEVINES AS INFLUENCED BY IRRIGATION AND PRUNING LEVEL

Diurnal changes in vine water status (_leaf and _stem), stomatal conductance (gs) and gas exchange (A, E) were monitored in a vigorous Tempranillo vineyard subjected to two irrigation regimes (0.3 x ETo and non-irrigated) and two pruning levels (10 and 18 shoots per vine). Irrigated vines were significantly less stressed throughout the day, while pruning level only influenced water status during certain hours of the day. _leaf was significantly correlated with g_s, but this relationship depended upon ambient PPFD and CO₂ levels.
Neither irrigation nor pruning level influenced vine photosynthesis (A) significantly, while stomatal conductance (gs) and transpiration (E) were both significantly higher in irrigated vines.
The gs of all the treatments was not significantly different between the hours of 12:30 (morning) and 17:30 (afternoon), however the higher temperatures during the afternoon increased vine E, while A was reduced.
Photosynthesis was limited at temperatures above 30° C, even though irrigated vines were not stressed.

I ISHS Workshop on Water Relations of Grapevines

M.J. Sipiora, J.R. Lissarrague

transpiration, photosynthesis, pruning, irrigation, Tempranillo

https://doi.org/10.17660/ActaHortic.1999.493.11