Cumulative effect of deficit irrigation and salinity on vine responses
Climate change is increasing water needs in most of the wine growing regions while reducing the availability and quality of water resources for irrigation. In this context, the sustainability of Mediterranean viticulture depends on grapevine responses to the combinations of water and salt stress. With this aim, this work studies the effects of deficit irrigation and salinity on the physiology of the Tempranillo cultivar (Vitis vinifera L.) grafted onto a drought and salinity tolerant rootstock (1103 Paulsen). The experiment was carried out in 2020 in a vineyard with a 22 factorial design located in Moncada, Valencia, Spain. The factors studied were two sustained irrigation regimes (100% and 50% of crop water needs) with two water salinity levels (EC of 0.8 and 3.5 dS m–1). Results showed that water deficit significantly impacted vine water relations and leaf gas exchange at the beginning of the season, but that throughout the season the vine adapted to water availability by regulating vigor. Total leaf area was also reduced by salt stress. However, the effect of salinity on vine water status became more evident as the season progressed. Despite the osmotic adjustment caused by both water deficit and salinity, the strong relationship between soil water potential (YPD) and gas exchange rates revealed the cumulative effect of both factors on vine water status. Similarly, chloride content was increased by the effect of salinity but also of water deficit in leaf and petiole, as well as in grape. Cumulative effects were also observed in the reduction of berry mass and in the increase of total soluble solids and must pH, but not in vine yield. These results evidence the importance of assessing abiotic stresses in combination. Experiments are ongoing to evaluate the effect on the agronomic response and possible carry-over effects.
Acknowledgements: This research has been funded by the Agencia Estatal de Investigación with FEDER (grant number PID2021–123305OB-C31).
Issue: ICGWS 2023
1 Instituto Valenciano de Investigaciones Agrarias, Centro para el Desarrollo Agricultura Sostenible, Apartado Oficial 46113, Moncada, Valencia.
2 Grupo de investigación de Biología de las Plantas en Condiciones Mediterráneas-Universidad de las Islas Baleares (PlantMed-UIB), Cra. de Valldemossa, km 7.5, 07122, Palma.
3 CSIC, Departamento de Ecología, Centro de Investigación sobre Desertificación (CSIC-UV-GV), Carretera CV‑315, km 10.7, 46113 Moncada, Valencia.