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Aim: The aim of the survey was to investigate if the grafting type influences the foliar expression of Esca during summer. Methods and Results: Observations were conducted on plots distributed in two French winegrowing regions (two different climatic regions) with two varieties (Cabernet-Sauvignon in the Bordeaux region and Mourvèdre in Provence). Three grafting types were compared: Omega graft, Whip and Tongue graft, and full cleft graft. For both varieties, we found a significant effect of the type of grafting on the foliar development of Esca symptoms. Full cleft grafted plots showed a significantly lower percentage of Esca foliar symptoms than the other two modalities, which were not significantly different from one another. Concerning Omega grafted plots, a significant difference in the rate of Esca foliar symptoms was highlighted compared to full cleft grafted plots, with a higher rate on Omega grafted plots, but these plots were also younger. Conclusions: The study established, for the first time, the difference between full cleft field grafted plots and Omega and Whip and Tongue grafted plots, revealing a higher incidence of Esca on the latter types of grafting. Significance and impact of the study: The spread of mechanical graft could be one of the factors explaining the increasing incidence of Esca in vineyard.

Aim: Grapevine plants from the Bordeaux wine region (France) showing symptoms of fanleaf degeneration, but negative for the two main fanleaf viruses were screened by ELISA for other nepoviruses that could explain the symptoms. Methods and results: ELISA tests were performed over a 3-year period (2009-2011) on leaves and woody canes. A total of 665 grapevine plants grafted with Merlot, Cabernet franc and Cabernet-Sauvignon, were found free from Grapevine fanleaf virus (GFLV) and Arabis mosaic virus (ArMV) but infected with Tomato black ring virus (TBRV). The Longidorid nematode species Longidorus attenuatus, known as the TBRV vector in grapevine, was detected from soil samples collected in the infected area. Conclusion: Both the virus and its vector might have originated from a vegetable garden established prior to vine planting, considering that the TBRV-infected area with the most fanleaf degeneration symptoms co-localizes with this previous garden. Significance and impact of the study: This is the first record of TBRV infection in a grapevine plot in France.

The influence of soil type and preparation on vine development and grape composition was investigated in a 50 ha estate located in Saint-Emilion (Bordeaux, France) and planted predominantly with Merlot. Part of the vineyard was planted down the slopes and another part of the vineyard was planted on terraces, where soils were profoundly modified through soil preparation. Grape composition (berry weight, sugar, total acidity, malic acid and pH), vigor (pruning weight), vine nitrogen status (Yeast Available Nitrogen (YAN) in grapes) and vine water status (δ13C) was measured at a very high density grid of 10 data points per hectare. Water deficit was globally weak over the estate because of high soil water holding capacity whereas vine nitrogen status was highly variable. Vine vigor and grape composition were predominantly driven by vine nitrogen status. On terraces, where soils were deep, due to invasive soil preparation, water deficits were particularly small or non-existent and vine nitrogen status was highly variable. Grape quality potential was medium to low, except in places with low nitrogen status, but at the expense of low yields. On parcels planted down the slopes water deficits were recorded because vine rooting was limited by compact subsoils. Vine nitrogen status was homogeneous. Grape quality and yield were medium to high and relatively homogeneous. When possible, downhill plantations are to be preferred over terraces because in the latter vine yield and quality parameters are highly variable because of massive soil movements prior to plantation.