New Insights into Esca of Grapevine: The Development of Foliar Symptoms and Their Association with Xylem Discoloration

Abstract

Lecomte, P., Darrieutort, G., Liminana, J.-M., Comont, G., Muruamendiaraz, A., Legorburu, F.-J., Choueiri, E., Jreijiri, F., El Amil, R., and Fermaud, M. 2012. New insights into esca of grapevine: The development of foliar symptoms and their association with xylem discoloration Plant Dis. 96:924-934.A new study on the development of foliar symptoms of esca was carried out from 2004 to 2006 in five mature vineyards in Aquitaine, France. Symptoms were monitored for severity and changes over time. Initial foliar symptoms were characterized by the presence of drying zones or discolorations (reddening or yellowing), which are symptoms that have also been attributed to Black Dead Arm (BDA). Then, the less-severely affected leaves persisted throughout the summer and developed into typical "tiger-stripe" symptoms of esca. The most severely symptomatic leaves fell soon after symptoms appeared. Severely diseased vines showed typical apoplectic or acute forms of esca that did not differ from the severe BDA forms. The appearance of leafsymptomatic vines increased uniformly over time, reaching a maximum incidence by the end of July. A second survey in 41 European and Lebanese vineyards showed that longitudinal discolorations were visible under the bark of 95% of the vines showing foliar esca symptoms. These wood symptoms, also previously attributed to BDA, appeared as xylem orange-brown stripes. Thus, foliar symptoms of esca showed transitory phases which overlapped with some BDA descriptions. Most of these symptoms, in the west-palearctic regions that were investigated, were commonly associated with the presence of one or several xylem discolorations.

Susceptibility of Cultivated and WildVitisspp. to Wood Infection by Fungal Trunk Pathogens

“…Therefore, we hypothesized that germplasm accessions with resistance to these other grape diseases may have resistance to trunk diseases. This is because Botryosphaeria dieback and Phomopsis dieback are not associated with diagnostic foliar symptoms (4,20,42), and foliar symptoms of Esca have very rarely been reproduced consistently under controlled conditions (22). Additionally, the North American hybrid Fennell 6 (V aestivalis) x Malaga (V. vinifera) DV1T0166, which is resistant to the obligate biotrophic fungus E. necator (9), showed higher susceptibility to E. lata than most V vinifera cultivars.…”

“…Grapevine infections by fungal trunk pathogens result consistently in the formation of cankers and discolorations of the wood, but not all trunk pathogens cause diagnostic foliar symptoms. In contrast, grapevines with Botryosphaeria dieback do not develop diagnostic foliar symptoms, but, instead, develop spur dieback, which is a characterisfic of all of the trunk diseases (20,42). aleophilum) (22), is associated with foliar symptoms ranging from a distinct interveinal chlorosis and necrosis of leaves on individual shoots to the total wilting of all leaves on the entire plant (20).…”

“…aleophilum) (22), is associated with foliar symptoms ranging from a distinct interveinal chlorosis and necrosis of leaves on individual shoots to the total wilting of all leaves on the entire plant (20). Grapevine infections by fungal trunk pathogens result consistently in the formation of cankers and discolorations of the wood, but not all trunk pathogens cause diagnostic foliar symptoms.…”

Deciphering the Niches of Colonisation of Vitis vinifera L. by the Esca-Associated Fungus Phaeoacremonium aleophilum Using a gfp Marked Strain and Cutting Systems

“…It is characterised by a brown red discoloration and black streaking in the xylem (considered as ‘young esca’) with the later development of a white rot in the trunk (‘esca proper’). Both young esca and esca proper in the trunk are associated with leaf tiger stripe symptoms as well as symptoms on berries [6–8]. Plants with heavily damaged trunks may suddenly die due to esca symptoms.…”

A critical review of plant protection tools for reducing pesticide use on grapevine and new perspectives for the implementation of IPM in viticulture

“…In fact research (Mugnai et al, 1999;Bertsch et al, 2013) demonstrated the important role of both nursery (Surico et al, 2004) and vineyard management in the infection and symptom development. For example, training systems and pruning techniques not only create infection courts for pathogens, but also favour dysfunctions in water flow in the vine (Lecomte et al, 2012). Indeed, water flow impairment, interacting primarily, but not exclusively, with pathogen virulence factors (i.e.…”