Influence of Different Irrigation Strategies on Vegetative and Productive Parameters of Vitis vinifera L. 'Cannonau'

摘要

A four years experiment on irrigation of Cannonau grapevine was carried out to test as means of improving water management sustainability and water saving, innovative irrigation strategies compared to the farmer irrigation management (FIM). They were Full irrigation (FI-100% ETc), Partial Rootzone Drying (PRD-50% ETc), Regulated Deficit Irrigation (RDI-50% ETc) and Sustained Deficit Irrigation (SDI-25% ETc) characterised by same turn and different volume. Furthermore, the experiment allowed to study the influence of different irrigation strategies on grape and must production on this Sardinian native grapevine in one of its typical lands (Alghero's DOC). The experiment was characterized by a randomized blocks design and irrigated by sub surface irrigation system. The parameters relieved were: water requirements, quality and quantity productions, clusters biometry and plants phenology, pruning wood, soil water content, and both maximum daily shrinkage (MDS) and stem water potential (SWP) as water stress indicators. Results showed that moderate or severe irrigation water reductions didn't induce a sensitive improvement on quantity or quality parameters in comparison with the well-watered treatment. The most productive treatment was FIM and the most reducing was SDI. Contrary to the expected result, PRD treatment production wasn't better than the RDI production that could put in evidence a probable Cannonau near-isohydric behaviour like the Grenache. Both water stress indicators (SWP and MDS) gave an accurate differentiation in particular between the farmer irrigation management and other treatments rather than among innovative treatments.