University Of Tasmania

File(s) under permanent embargo

Assessing and managing disease affected fruit in the vineyard: the Australian experience

conference contribution
posted on 2023-05-23, 05:34 authored by Katherine EvansKatherine Evans
The unusually wet season across south-eastern Australia in 2010–2011 saw grapegrowers exhausted after endless hours of spraying, often in vain, to control the dreaded trifecta of downy mildew, powdery mildew and botrytis bunch rot (botrytis). Mildew infection during flowering and fruit set damaged grape berries providing infection sites for the opportunistic ‘wound’ fungi that cause bunch rot. However, the interaction between the diseases was not always detrimental. There were reports that defoliation caused by downy mildew increased air circulation in the canopy which, in turn, reduced the severity of bunch rot. Nevertheless, the pressure on vineyard managers to act in controlling these diseases was relentless, even when certain actions, with hindsight, proved fruitless. Liz Riley, a viticulturist and consultant in the Hunter Valley, coined the term ‘koalas’ to denote grape bunches with large areas of ‘grey and fuzzy’ mould (Figure 1). The case for crop rejection can be all too clear when there are numerous ‘koalas’ and nearly every bunch is rotten to some degree.


Publication title

Making the Best Out of Difficult Vintages: Managing Sub-optimal Fruit in the Winery


PR Petrie




0 9775256 9 4


Tasmanian Institute of Agriculture (TIA)


Australian Society of Viticulture and Oenology

Place of publication

Adelaide, South Australia

Event title

Australian Society of Viticulture and Oenology 2011

Event Venue

Adelaide, South Australia

Date of Event (Start Date)


Date of Event (End Date)


Rights statement

Copyright 2013 Australian Society of Viticulture and Oenology

Repository Status

  • Restricted

Socio-economic Objectives

Wine grapes

Usage metrics

    University Of Tasmania