°Distinct spread of GRBV in CA and NY

Limited information is available on the spread dynamics of grapevine red blotch virus (GRBV, genus Grablovirus, family Geminiviridae) in vineyards.  Secondary spread of GRBV was documented in vineyards in California but not in New York. Increase in annual disease incidence (4.8, 0.13, and 0%) was unrelated to the estimated initial source of inoculum at planting (1, 40, and 40%) in the  three study vineyards. Limited genetic diversity of GRBV populations in newly infected vines supported localized spread in California vineyards, and suggested the planting material as the primary source of inoculum. Among the community of hemipteran insects visiting two of the three study vineyards, populations of Spissistilus festinus, the vector of GRBV, were absent in the NY vineyard and in one of the CA vineyards.  Together our findings illustrate differential disease progress in distinct vineyard ecosystems, and support the elimination of virus inoculum sources as an actionable disease management strategy across vineyards.

Cieniewicz et al. 2019 Phytobiomes