Demonstration of best practice Botrytis control strategies on a vineyard in the Yarra Valley region of Greater Victoria

Abstract

Demonstration of best practice botrytis control strategies on a vineyard in the Yarra Valley region of Greater Victoria

Summary

Botrytis is one of the most important sources of economic losses in Yarra Valley vineyards. This project was one of three similar RITA funded projects (in three different regions) all having the same objectives, to demonstrate, assess and refine best practice Botrytis management strategies in a vineyard. The Greater Victoria Wine Grape Industry Development Committee (IDC) instigated as a two-year project the Best Practice Botrytis Initiative by the IDC, GWRDC, Monash University and the Department of Primary Industries, along with the three regional associations, as co-investors.

The aims of the broader project are, by June 2004, to develop and extend best practice Botrytis management strategies to all wine grape growers across Greater Victoria.

This project successfully adapted the latest national research on Botrytis to vineyards in the Yarra Valley in the management of Botrytis. Growers were involved in commenting upon, and adding to, a checklist of prompts that highlighted actions that could be implemented in the vineyards in the Yarra Valley where Botrytis is a major problem. Growers from the three regions expressed a need for a document to accompany the checklist explaining more fully the reason(s) for the actions suggested. The checklist and the accompanying document and CD were available in early 2004.

Information days held at Lusatia Park vineyard allowed data to be presented by the researchers and growers to be actually involved in assessing the checklist and providing feedback on its relevance to them.

This site had very little management and developed a heavier than normal Botrytis load most seasons. Significant management changes needed to be made. Open canopy by shoot thinning, bunch thinning and leaf plucking on the eastern side of the canopy were used as the management protocols during the experimental seasons.

The drought during the summer of 2002-2003 was instrumental in lower than normal expression of Botrytis, so management strategies implemented on the Lusatia Park vineyard have not been tested under high disease pressure conditions. However, all berry samples taken from this vineyard at harvest were Botrytis infected. Because of the dry weather there was little Botrytis expression and the harvest was acceptable. This outcome provides evidence that it is Botrytis expression, rather than Botrytis infection that is a key issue at harvest.