Drought resilience improvement in temperate-climate vineyard ecosystems Prof. Stefano Poni Università Cattolica del Sacro Cuore, Italy

Meterological drought has a quite complex definition as an inherent precipitation deficiency might be exacerbated by poor soil management - leading, in turn, to reduced water reservoir – and by high temperatures thereby conducive to high evapotranspiration. The three main E27 wine producing countries, Italy, France and Spain—accounting for about 67% of total world vine production are all facing the above threat. Moreover, the scenario might worsen when an objective meteorological drought couples with a water scarcity situation (e.g. no resources for supplemental irrigation available or excessive cost of blue water retrieval and distribution. Last but not least, in the above countries irrigation is often forbidden or severely constrained.

In Italy, survival of viticulture in mostly hilly areas falling within a temperate climate type with hot summers is bound to adoption of effective drought resilience techniques aimed at maintaining competitiveness while lowering vineyard water footprint and making additional water supply unnecessary. Not addressing the issue means that an increasing fraction of sloping sites will be abandoned with obvious negative environmental and social consequences.

In this review paper, we streamline a few modifications in vineyard establishment and management that have proven to be quite useful, in lack of irrigation, to increase tolerance to drought and to post-pone occurrence of irreversible damage to the leaves and incapability to promptly respond to any rewatering event.

Among those we will cover in brief the importance of row orientation, canopy geometry (vertically shoot positioned vs sprawl canopies), cover crop management (i.e. water use vs tilled soil and prior and after mowing), new rootstock material (e.g. performance of the new drought tolerant M4 vs older traditional rootstocks genotypes) and application ok kaolin sprays to the grapevine canopy.