Does predawn water potential discern between irrigation treatments in Galician white grapevine cultivars?

Abstract

Aims: To evaluate the usefulness of predawn water potential (Ψpd) to assess the water status of Galician grapevine cultivars for irrigation purposes. Methods and results: Three Galician white grapevine cultivars (Albariño, Godello and Treixadura) were subjected to rain-fed and irrigation conditions during the 2013 growing season. Diurnal changes in leaf water potential (Ψl) were measured using a pressure chamber on days with high evapotranspiration demand. Stem water potential (Ψs) was measured at midday. Ψpd was not able to discriminate between treatments, whereas Ψl and Ψs at midday were able to detect significant differences in water status among plants. Conclusion: Ψpd was not useful to evaluate vine water status under the Galician climatic conditions. In contrast, both Ψl and Ψs were effective for detecting differences between treatments and can thus be used for irrigation management purposes. Significance and impact of the study: This is the first study evaluating water status of Galician grapevine cultivars. It also provides useful information about the strategy for its control through measurements of midday Ψl or Ψs.

Keywords

• leaf water potential
• Albariño
• Godello
• Treixadura
• water status