Salt tolerant rootstocks for long-term sustainability in the Limestone Coast

Long term drought in the first decade of the 21^st century coincided with rises in the salinity of ground waters used for irrigation in some supplementary irrigated regions and has forced an abandonment of the premise that underpinned the establishment of many of the fully irrigated areas; that is that in 99 out of 100 years the water resource will be able to provide 100% of full irrigation allocation. Vineyard sustainability will depend in part on the ability of plantings to weather these variations in the quality and quantity of irrigation waters. Rootstocks can enhance sustainability by conferring tolerance to reductions in water quality and quantity. This project was developed to address these issues in a supplementary irrigated region, the Limestone Coast of SA. A variation to the project in 2010 supported its extension into a fully irrigated region, the Riverland of SA. The project addresses these issues by assessing whether the stability of a fundamental property of grafted vines, yield, is affected by aging; by increasing the range of rootstocks for which we have information on salt exclusion properties; by determining whether rootstock salt exclusion properties are modified by reduction in irrigation allocations; and by assessing rootstocks tolerance to conditions of near zero irrigation.