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Background and Aims: Eutypa and Botryosphaeria dieback are diseases that affect vineyards worldwide, reducing productivity and longevity. The ability of the causal pathogens Eutypa lata and Diplodia seriata to colonise grapevine canes was investigated in the search for resistance or tolerance to trunk diseases. Methods and Results: Visual assessments of 174 winegrape cultivars (Vitis vinifera) in a mature germplasm collection in the Barossa Valley in South Australia revealed substantial variation (0–98%) in severity of foliar symptoms and dieback. A selection of 18 cultivars representing those without symptoms or low (<10%) severity was compared with the susceptible cultivars Shiraz and Sauvignon Blanc. Inoculation of canes in situ in the vineyard and detached canes in the greenhouse, confirmed variability among cultivars for the extent of pathogen colonisation. Conclusions: Cultivars varied in susceptibility to colonisation by E. lata and D. seriata, with some differences between the two pathogens in terms of the ranking of cultivars. Muscadelle was most resistant to colonisation by both pathogens, and Sauvignonasse was the most susceptible. Significance of the Study: Knowledge of cultivar susceptibility to grapevine trunk diseases will assist in prioritisation of disease management strategies. Identification of cultivars with resistance could inform selection of planting material and may lead to improved breeding programs in the future. [ABSTRACT FROM AUTHOR]

Background and Aims: The trunk disease Eutypa dieback causes financial losses in grapegrowing. The influence of two pruning methods, namely cane and spur pruning, on the incidence and severity of Eutypa dieback in Shiraz grapevines was investigated as pruning wounds are a major point of entry for the causal agent Eutypa lata. Methods and Results: The surface area of pruning wounds in 11 Shiraz vineyards in the Barossa Valley was measured. The incidence of Eutypa dieback in all of those vineyards and disease severity in two vineyards were determined. The surface area of wounds exposed by cane pruning was 21–33% smaller than for spur pruning. The incidence of foliar symptoms and the severity of disease were 50 and 38% lower, respectively, in cane‐pruned than in spur‐pruned vines. For cane‐pruned vines, an increase in bud number retained was associated with a smaller increase in wound surface area than for spur‐pruned vines. Conclusions: The incidence and severity of Eutypa dieback were greatest where the total surface area was largest rather than the size of individual cuts exposed by pruning. Significance of the Study: Limiting the total surface area exposed by pruning in plantings of Shiraz vines is likely to reduce the incidence and severity of Eutypa dieback. [ABSTRACT FROM AUTHOR]