Sustaining grapevines infected with Eutypa dieback

Abstract

This project developed practical and efficient methods for eutypa dieback control, determined the effect of environmental and production stresses, evaluated remedial surgery treatment for sustaining grapevines and established the presence and extent of eutypa dieback in emerging grapegrowing regions.

Summary

Eutypa dieback is a major disease of grapevines in Australia and worldwide caused by the fungus Eutypa lata that infects vines through pruning wounds, colonises wood tissue and causes dieback of cordons, stunting of green shoots and leaf distortion. Eutypa dieback threatens the sustainability of premium vineyards and is becoming a problem in most cool climate growing regions of southern Australia. This disease reduces growth and yield and if unmanaged eventually kills vines.

A number of pruning wound treatments have been evaluated and some controlled the disease. Physical barriers such as Gelseal, Greenseal, Garrison, Agseal and an acrylic paint were effective and are recommended for use especially on large wounds, such as those made during remedial surgery. Of the fungicides tested, Bavistin (carbendazim) and Folicur (tebuconazole) were the most effective but Scala (pyrimethanil), Switch (cyprodinil + fludioxonil) and Shirlan (fluazinam) were also effective when applied at rates higher than currently registered for use on other grape diseases. Bavistin, Folicur and Shirlan also controlled Botryosphaeria canker. Further evaluation is required to determine optimal rates for eutypa dieback control. Garlic and lactoferrin also showed promise as alternatives to fungicide application