Temporal and spatial dynamics of grapevine anthracnose and its relationship to pathogen survival

Abstract

Anthracnose, caused by Elsinoë ampelina, is an economically important grapevine disease in south and southeast Brazil. Control is achieved by lime sulphur application during grapevine dormancy and foliar fungicide sprays until the berries are half‐grown. This study assessed the temporal and spatial progress of grapevine anthracnose under field conditions in order to describe the disease dynamics and its relationship to pathogen survival. The experiment was carried out in a vineyard of table grape Vitis labrusca in Brazil, during the 2014 and 2015 growing seasons. The incidence of vines with diseased leaves, stems and berries and the disease severity on leaves were recorded from bud break to veraison. Monomolecular, logistic and Gompertz models were fitted by non‐linear regression to the incidence and severity data over time to characterize the temporal progress. Ordinary runs, dispersion index, modified Taylor's power law and spatial hierarchy analyses were used to characterize the spatial pattern of diseased plants. The monomolecular model showed the best fit for the incidence progress, with disease progress rates ranging from 0.051 to 0.136 per day. In both seasons, the incidence of diseased plants reached 100% 1 month after bud break. However, the incidence of diseased leaves per plant was around 60% and leaf disease severity was lower than 5% for both years. Ordinary runs and dispersion index analyses revealed that diseased grapevines were distributed randomly on the majority of the assessment dates. Meanwhile, a slight aggregation of diseased vines was observed in the modified Taylor's power law analysis. Our results suggested that the progress of anthracnose incidence and severity over time was governed mainly by the income of the primary inoculum, which survived in the vineyard. Therefore, anthracnose control measures in Brazilian vineyards should be focused on the reduction in inoculum within the vineyard.

Resistance of Vitis germplasm to anthracnose in Southern Brazil

“…reported to be favorable for E. ampelina infection(Santos et al 2020;Carisse et al 2020;Ji et al 2020). In this study, the frequent rainfall and average temperatures, mainly ranging from 15 to 20 o C, created favorable conditions for E. ampelina infection and development.…”

“…accessions displayed immunity to E. ampelina, and they exhibited signi cant variation in their resistance or susceptibility to the pathogen. Contrasting levels of resistance or susceptibility to E. ampelina under eld conditions have been reported for both American and Asian Vitis species and interspeci c hybrids(Santos et al 2020;Zhi et al 2021;Otto et al 2023).…”

Current status and future prospects of grapevine anthracnose caused by Elsinoe ampelina: An important disease in humid grape‐growing regions

“…For instance, big and circular lesions on leaves are formed on susceptible cultivars, whereas small and irregular lesions are formed on resistant cultivars (Gao et al, 2012;Kono et al, 2012). Ontogenic (age-related) resistance to E. ampelina is observed in grapevines, where young tissues are susceptible to pathogen infection and disease development, whereas old tissues are highly resistant (Santos et al, 2020;Thind, 2015). In addition, the lesion size on young leaves is greater than that on old leaves (Brook, 1973;Suhag & Grover, 1972).…”

“…Ontogenic (age‐related) resistance to E . ampelina is observed in grapevines, where young tissues are susceptible to pathogen infection and disease development, whereas old tissues are highly resistant (Santos et al, 2020 ; Thind, 2015 ). In addition, the lesion size on young leaves is greater than that on old leaves (Brook, 1973 ; Suhag & Grover, 1972 ).…”

“…A fungicide spray programme should be initiated early in the growth (budburst) and dormancy stages on susceptible cultivars to prevent the infection of young leaves and reduce the overwintering inoculum, especially when a history of anthracnose in the vineyard is present (Carisse & Lefebvre, 2011 ; Magarey, Coffey, et al, 1993 ; Santos et al, 2020 ). Copper sulphate, lime sulphur, and Bordeaux mixture have been used as dormant sprays (du Plessis, 1940 ).…”