Dr Rob Walker 2020 ASVO Viticultural Paper of the Year

This award honours an outstanding author(s) of a paper published in the AJGWR in the previous 12 months where the potential application of the research on viticultural practices is deemed by an industry/science-based panel to have the most impact.

The 2020 Viticulture paper of the year was awarded to Dr Rob Walker, from the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and co-authors for the paper:

Walker, R., Blackmore, D., Clingeleffer, P., Holt, H., Pearson, W. and Francis, I. (2019), Effect of rootstock on yield, grape composition and wine sensory attributes of Shiraz grown in a moderately saline environment. Australian Journal of Grape and Wine Research, 25: 414-429. https://doi.org/10.1111/ajgw.12409

The capacity of salt-challenged grapevines to limit the uptake and transport of chloride and sodium to leaves and berries (termed ‘salt exclusion’) is one measure of salt tolerance. Other measures are yield, balanced growth, good fruit and wine composition and wine sensory attributes. The paper addresses the role of rootstock vigour in the salt tolerance response, the sensory attributes of wines made from the rootstocks, including salty taste, and examines a salt tolerance index that combines several parameters for assessment of salt tolerance.        
Shiraz grafted to eight rootstocks with different vigour rankings, including three low to medium vigour rootstocks bred by CSIRO, were drip irrigated with moderately saline water over two seasons. The least vigorous rootstock, M6262, had highest wine chloride concentration of 482 and 384 mg/L in 2012 and 2013, respectively, however, salty taste and a thickness mouthfeel (viscosity) were significant only in 2012. Wines from the other rootstocks were all less than 175 and 40 mg/L of chloride and sodium, respectively, and salty taste was not detected. A salt tolerance index based on yield, leaf area index, grape juice chloride and sodium concentration and wine colour density provided a promising measure of rootstock salt tolerance compared with the traditional parameters of yield and/or capacity for salt exclusion.
Rob completed his undergraduate and PhD degrees at the University of Tasmania. He joined CSIRO Horticulture (Adelaide) in 1975 and in 1976 moved to the CSIRO Merbein (Victoria) Laboratory. In 1978-79, he undertook a Research Fellowship at Cambridge University. After a further 30 years at Merbein, 24 as Site/Program Leader, he returned to Adelaide in 2009, undertaking Theme and Program leadership roles from 2011 to 2015. His research on salt tolerance and rootstock salt exclusion is widely recognised nationally and internationally. He has over 250 publications, including over 100 in international refereed journals. He is currently a CSIRO Honorary Post Retirement Fellow, Affiliate Professor University of Adelaide and Adjunct Professor Charles Sturt University.