Effective management of botrytis bunch rot for cool climate viticulture

Botrytis bunch rot, caused by Botrytis cinerea, continues to cause large seasonal variability in grape production and wine quality. This project identified pathogen, vine and weather factors that can be practically monitored during the season for predicting botrytis risk. Quantitative relationships between botrytis and individual risk factors were determined and these relationships incorporated into a prototype predictive model. The predictive model,known as the Botrytis Decision Support Model (BDSM), will be delivered in a decision support system for supporting advice from industry service providers and vineyard technical managers to vineyard staff, including:

• fungicide applications

• vine canopy management

• planning of harvest operations to minimise crop loss from botrytis

• retrospective analysis of the performance of botrytis control programs.

This report also describes:

• quantitative methods that were validated for studies of botrytis bunch rot in grapevines,

• a new quantitative polymerase chain reaction (PCR) assay for quantifying B. cinerea DNA in grape berries,

• effects of fungicides and canopy manipulation on botrytis severity,

• whole-of-block experimentation for understanding spatial variation in treatment responses,

• a sampling strategy for monitoring botrytis as an input to the BDSM, and

• equipment, data, services, infrastructure and education required for adoption of the BDSM.