A. Analyze incidence of multiple virus diseases in a 2014 survey of grape blocks in the California north coast region and relate virus incidence to block planting date.
B. Interpret patterns of virus incidence in the 2014 survey in relation to entry of different virus diseases into the California grape certification system.
C. Develop a grower information pack and slide presentation to summarize survey information on long term changes in vine health and impact of clean plant strategies on virus incidence.
D. Adapt information from previous epidemiology studies on leafroll and Red Blotch to develop sample size calculations and sampling schemes for virus assessment in grape blocks.
E. Work with grower participation groups in Oakville and Lodi to demonstrate and evaluate virus sampling protocols
F. Develop grower information pack and slide presentation to summarize sampling approaches for virus management in different production situations
G. Make sample size calculations available online via a simple, free web page linked to supporting information on virus diagnostics and epidemiology.
Objective A: As a reminder, we surveyed approximately 100 blocks of wine grape in the North Coast region in the fall of 2014 for the incidence of nine viruses, including Grapevine Red Blotch associated Virus (GRBaV) and Grapevine Leafroll associated Virus (type 3) (GLRaV-3). Ten randomly selected vines in each block were sampled by collecting two petioles per vine. Samples were tested using a set of species-specific PCR primers after DNA/RNA extraction.