Analysis of the pest risk from Grapevine flavescence dorée phytoplasma to Austrian viticulture
R. Steffek, H. Reisenzein and N. Zeisner
In 2004, Scaphoideus titanus, vector of Grapevine flavescence dorée phytoplasma, was first recorded in Austrian vineyards. The absence of the phytoplasma in 2004-06 was confirmed by molecular analyses of grapevine and vector samples. To estimate the risk to Austrian viticulture a Pest Risk Analysis (PRA) was conducted, following the EPPO decision support scheme. The highest risk of introduction arises from the extensive trade in rootstocks and, especially for vineyards located along traffic routes and waterways, from the passive or active spread of the vector. Climate will not limit the establishment of the vector in the large northern Austrian vine-growing regions of Niederösterreich and Burgenland. At present the probability that the disease and vector become associated is restricted to parts of South Styria. Plant protection practice cannot prevent the establishment and spread of vector populations, especially in sustainable production systems, which forms more than 70% of the total Austrian viticulture area. The possibility for containment or even eradication is given, but requires an early recognition of the vector and disease and the immediate initiation of measures. Otherwise, losses to vine growers, follow-up costs for eradication and additional efforts in the production of plants would be substantial. Following the assessment, legal measures and recommendations to prevent disease entry and to minimise impacts of established vector populations are considered.