Recovery after curettage of grapevines with esca leaf symptoms

Abstract

Grapevine curettage was re-introduced in France in the early 2000s, and is important for facilitating recovery of plants from esca disease. This surgical practice involves removal of deadwood of vines with leaf symptoms, focusing on white rot generally observed at the centres of grapevine trunks. Assessment of the efficacy of this practice was initiated in the Bordeaux region in 2014. One ‘Sauvignon Blanc’ vineyard severely affected by esca was initially surveyed in the summer of 2014, to identify and treat vines with esca foliar symptoms. Annually thereafter, from 2014 to 2018, selected vine stocks were curetted. Two other ‘Sauvignon Blanc’ vineyards also displaying high levels of esca damage were added to the study in 2015 and 2016. Curettage treatments ceased in 2018, resulting in 11 trials (vineyard × year combinations). In total, 856 vines (422 curetted and 434 control vines) were then surveyed annually up to 2021, for assessments and comparisons of esca development. At each site, plants with esca symptoms recovered well after curettage: on average 85% of all curetted vines became asymptomatic the year immediately after the treatment. Six years after treatment, for curettage campaigns carried out in 2014 and 2015, more than half of the curetted vines were symptom-free, whereas <12% of the control vines were asymptomatic, and gradual loss of efficacy was observed at each site. The mean annual proportion of efficacy erosion was approx. 8% per year. This study highlights the possible short- and mid-term benefits of trunk surgery to enable recovery of esca-affected vines, and for them to recover and remain leaf-asymptomatic for several years.

Exploring the role of cultivar, year and plot age in the incidence of esca and Eutypa dieback: insights from 20 years of regional surveys in France

“…the use of certain rootstocks or types of pruning) may be specific to a particular cultivar and wine region. Such factors are known to affect susceptibility to esca (Lecomte et al 2018). It was not possible to investigate these confounding factors here, but the observed differences in esca incidence between the cultivars studied here were correlated with the range of susceptibility of the same cultivars quantified over several years in a common garden vineyard (Gastou et al 2024).…”

Fungal trunk diseases of fruit trees in Europe: pathogens, spread and future directions

“…In viticulture, intensive pruning schemes (e.g. spur or cane pruning), can cause more frequent external FTD symptoms than minimal pruning schemes (Lecomte et al, 2018(Lecomte et al, , 2022Kraus et al, 2019). It was also assumed that intensive pruning causes more and larger pruning wounds on grapevine trunks, leading to increased infections by wood degrading fungi, and consequent interruption of host vascular systems and increased symptoms (Travadon et al, 2016;Kraus et al, 2022).…”

Grapevine pruning strategy affects trunk disease symptoms, wood pathobiome and mycobiome

“…Esca wood symptoms include black spots in trunk crosssections and streaking in longitudinal sections but can be surrounded by pink to brown wood discolorations, and in older vines, white rot is also common. Foliar symptoms associated with esca include tiger stripe leaf patterns, wilting, and apoplexy, ranging from a few leaves to the entire vine canopies (Mugnai et al, 1999;Surico, 2009;Lecomte et al, 2012;Lecomte et al, 2018).…”

“…Wood dieback symptoms caused by Eutypa and Botryosphaeria were less frequently recorded, although incidence of Botryosphaeria canker was reported to be increasing in several countries. In France, the National Grapevine Trunk Disease Survey reported that GTDs incidence increased nationally from 3 to 13% between 2003 and 2013, with esca being the most-widespread, whereas other GTDs such as Eutypa dieback were more region-specific (Fussler et al, 2008;Bruez et al, 2013;Lecomte et al, 2018). Esca foliar symptom expression has been shown to be erratic, linked to different amounts of annual rainfall, particularly in late spring to early summer (Calzarano et al, 2018;Kraus et al, 2019;Dewasme et al, 2022).…”

“…In contrast, the 'Guyot-Simple' system, similar to canepruned vines, trains one spur on each side of each vine, and creates large cuts close to the trunk head. This system was described to be conducive of GTDs (Lecomte et al, 2018). Following a survey of French vineyards, Lecomte et al (2018) noted that vine training forms with longs arms (cordons) decline less rapidly than short arm training forms.…”