Evaluating treatments and spray application for the protection of grapevine pruning wounds from infection by Eutypa lata

Abstract

Eutypa dieback threatens the sustainability of vineyards worldwide and limited treatments are available for control of the disease in grapevine. Following the loss of the effective benzimidazole fungicides, benomyl and carbendazim, there is a need to identify alternatives for the protection of pruning wounds against infection by ascospores of Eutypa lata. In this study, 24 fungicide and natural treatments were evaluated in the laboratory and field. Tebuconazole and carbendazim were the most effective fungicides for reducing colonization of pruning wounds inoculated with E. lata. Pyrimethanil and fluazinam also provided some control but were less effective than tebuconazole at the rates tested. Other treatments, such as cyprodinil + fludioxionil, pyraclostrobin, a garlic extract, and lactoferrin, reduced colonization of wounds by E. lata but require further evaluation at higher concentrations. Carbendazim applied to pruning wounds using tractor-driven sprayers reduced the incidence of pruning wound infection by E. lata to levels similar to that achieved by application with a paint brush.