Seminar searches for the sweet spot in wine

Around 200 grape and wine professionals from all aspects of the Australian wine industry came together in Mildura last month, to hear from Australian and international scientists they hoped could help in their search for that elusive and wholly unique wine ‘sweet spot’.

The Australian Society of Viticulture & Oenology’s (ASVO) annual two-day seminar was titled: ‘Searching for the sweet spot – the quest for optimal yield and quality’, and was held on July 24 and 25.

ASVO president Paul Petrie said the seminar was an opportunity to showcase the latest research and development in the area of optimising yield and quality, from both overseas and within the Australian wine sector.

“It’s a highly subjective idea – that ‘sweet spot’  –  but there’s some excellent research and work currently being undertaken around techniques such as canopy management, yield regulation as well as best practice business decisions aimed to help wineries achieve their desired sweet spot,” Dr Petrie said.

As well as a number of Australia’s top researchers presenting AGWA-funded research, the seminar also saw three international keynote speakers present their latest work.

Italy’s Professor Stefano Poni, at the Istituto di Frutti-Viticoltura, Università Cattolica del Sacro Cuore, Piacenza, Italy, presented the research he’s undertaking on the impact of leaf removal and the management of crop load and fruit quality, from a European perspective.

“Professor Poni definitely generated a lot of interest as he spoke about some dramatic improvements in quality through the use of mechanical leaf removal  – particularly in the Italian variety Sangiovese,” Dr Petrie said.

“It’s always interesting and valuable to hear these overseas perspectives, particularly when there’s an opportunity to ask questions and talk to the researcher in person and give it some Australian context.”

Professor Poni said pre-flowering leaf removal applied to remove at least six basal primary leaves had proven a reliable and consistent technique to reduce crop via either a lower fruit-set and/or berry size mechanism, while enhancing ripening primarily as a result of improved seasonal carbon assimilation per unit of crop.

Further desirable features achieved using this technique were looser bunches, hence less to rot, and higher relative skin growth which limited sunburn damage.

California-based Martin Mendez-Costabel, Manager Wine and Grape Supply at E&J Gallo Winery, offered his unique perspective on ‘Understanding the impact of cultural practices on fruit quality in California’.

Dr Mendez-Costabel used the seminar to talk about the very real and serious effects the water shortages in California are having on the industry there. This season is one of the driest on record and the previous season was also very dry.

Dr Petrie said Dr Mendez-Costabel also spoke about the development of new technologies allowing wine companies to employ ‘precision viticulture’ techniques to help influence the final quality of wine.

“These included assessing vineyard variability to assist with sampling and quality assessments, site selection and vineyard and irrigation design. They also use remote sensing to estimate irrigation requirements or use, which is especially relevant given the drought conditions. Even areas where the land has subsided due to over extraction of water could be identified,” he said.

“Gallo processes 1.2M tonnes which is almost as much wine as the whole of Australia, so some of the systems available to them could be perceived as being very different to what is available to a smaller producer here in Australia,” he said.

“However, I believe, Dr Mendez-Costabel did a very good job of demonstrating the management options and viticulture practices Gallo employ are as relevant and applicable on smaller scales…ultimately it’s about trying to achieve that balance in what you invest in the vineyard and what your wine is worth in the market.”

From New Zealand, Mike Trought, from Plant & Food Research, challenged the seminar guests to question the current dogma that high yields lead to inferior wine.

Dr Petrie said Dr Trought got the delegates pondering the economic relationship of yield and quality.

“He discussed his work on the risks associated with high yield over quality parameters, and presented some very interesting data that looked at different harvest dates, maturity parameters,  yield, and financial return from a hypothetical vineyard” he said.

Joining the international speakers were a long list of Australian researchers, from all of the nation’s wine and viticulture research institutions, as well as several viticulturists who offered their own experiences in the practical assessment and application of current Australian viticulture and oenology research.

“This year we had a number of viticulturists present a session around their own experiences, and hearing how the research is applied in real situations offers some very unique benefits not just to other grape and wine industry personnel  but the researchers as well,” Dr Petrie said.

A copy of the slides used by the 18 presenters are available for ASVO Members and seminar delegates via its website: asvo.com.au

Seminar Speakers (left to right). Jason Smith (CSU), Brett McClen (Brown Brothers), Martin Mendez-Costabel, Guillaume Antalick (CSU), Greg Dunn (NSW Department of Primary Industries), Paul Petrie (ASVO) Katja Suklje (CSU), Alain Deloire (CSU)
Seminar Speakers (left to right). Jason Smith (CSU), Brett McClen (Brown Brothers), Martin Mendez-Costabel, Guillaume Antalick (CSU), Greg Dunn (NSW Department of Primary Industries), Paul Petrie (ASVO) Katja Suklje (CSU), Alain Deloire (CSU)