Oral Presentation Science Protecting Plant Health 2017

Investigations on the spore dispersal patterns of eutypa and botryosphaeria dieback pathogens in Australian vineyards (4101)

Regina Billones-Baaijens 1 , Sandra Savocchia 1 2 , Matthew Ayres 3 , Mark Sosnowski 3 4
  1. National Wine and Grape Industry Centre, Charles Sturt University, Wagga Wagga, NSW, Australia
  2. Faculty of Science, Charles Sturt University, Wagga Wagga, NSW, Australia
  3. South Australian Research and Development Institute, Adelaide, South Australia, Australia
  4. School of Agriculture, Food and Wine, The University of Adelaide, Glen Osmond, SA, Australia

Eutypa dieback (ED) and botryosphaeria dieback (BD) are economically important diseases of grapevines worldwide causing cankers, dieback and eventually death of vines. These diseases persist in affected vines from season to season threatening the $8.3 billion Australian wine industry. The spores of ED and BD pathogens that infect primarily via grapevine pruning wounds are generally dispersed by rain splash and travel distances depending on wind speed. However, there is limited data on the climatic conditions required for spore release by these pathogens in different climatic regions of Australia. This study investigated the spore dispersal patterns of ED and BD pathogens in South Australia (Barossa Valley and Coonawarra) and New South Wales (Hunter Valley and Griffith) using Burkard spore traps. Spore trap tapes were collected and replaced monthly at each site and analysed using two quantitative PCR protocols (qPCR) developed to detect Diatrypaceae and Botryosphaeriaceae spores. Preliminary data analysed to date showed sporadic release of ED and BD pathogen spores at different times of the year with the highest number of spores detected in late winter and early spring when temperatures were relatively mild and rainfall was high. However, higher number of spores were trapped in New South Wales over summer compared to in South Australia. Spore release was found to be associated with rain with as little as 0.2 mm resulting in spore release of either pathogen but not all rain events resulted in spore release. Six spore traps have been further deployed across Australian wine regions, and will be monitored for a further three years. Data generated from this study will determine the critical times of the year when ED and BD pathogen spores are abundant in vineyards and this may assist growers in making decisions on optimal timing of pruning and wound treatment.