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Tasmanian Institute of Agriculture

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Published: 19 Nov 2019

Harriet and Nadine in wine cellar

Stunning wine cellars dug into the side of mountains, vineyard tours, wine tastings and the opportunity to make international connections. We’d be smiling too!

TIA PhD candidates Harriet Walker and Nadine Hölzel recently travelled to Malta and Italy to share their horticulture research on the international stage.

Harriet presented at the International Symposium on Precision Agriculture in Orchards and Vineyards, in Palermo, Sicily.

“There was a really good mix of people from all different backgrounds, including viticulture, horticulture, IT and engineering,” she said.

Harriet’s research is looking at ways to non-destructively measure vine canopy nitrogen content.

Nitrogen is an essential macronutrient for the whole wine making process and has an impact on plant growth right through to fermentation and the resulting wine.  

“If you don’t have enough nitrogen then the fermentation process will stall, but it is a fine balance because too much nitrogen will increase the vegetative growth and impact the quality of the grapes,” Harriet said.

“Currently to test nitrogen, growers have to take a minimum of 30 samples to obtain one nitrogen reading. It is time consuming, costly, destructive to the plants and the results can be difficult to understand. It is also not a real-time process as the samples need to be sent to an external laboratory for analysis.

“My research has investigated the use of handheld sensors which are currently on the market and Near Infrared (NIR) Spectroscopy, which could be adapted to measure real-time nitrogen content in vines.”

Harriet tested benchtop NIR systems and found that they had a 94 per cent accuracy and a portable NIR instrument which had a 76 per cent accuracy rate compared to the standard industry method.

“More research is needed, but there is great promise that we could find a system that growers could use themselves and even add into existing processes by putting it on a tractor or quad bike to minimise labour,” she said.

Harriet on a vineyard tour.

Nadine presented at the World Congress on Polyphenols Applications in Malta on her research into the anthocyanin content of cherries and how the human body processes them.

“My research is split into two parts. The first is focused on nitrogen in the cherry orchard and the second is about the nutrition of cherries once they are consumed,” Nadine said.

“From the nutrition side I am looking at whether the amount of anthocyanins (the red pigments found in cherries) correlates with how much the body processes.

“It is not as simple as what we consume is what our bodies take up,” she explained.

“I call it my tree to wee study. I am starting in the orchard to work out the treatment for the tree to produce cherries of the best quality and highest anthocyanin content, then I follow the pigments through the body and see what comes out at the end.”

The project is a pilot study with 20 participants, but Nadine hopes it will provide clues to how cherry anthocyanins work and lead to bigger studies.

Presenting her research to an international audience led to several new contacts and even some potential collaborators from the USA and Canada.

“It was a good atmosphere with people from all over the world including Europe, America, South America and New Zealand. I was the only one from Tasmania,” Nadine said.

Harriet and Nadine also took the opportunity to visit some research centres in northern Italy, including the University of Bolzano, the Laimburg Research Institute and the Edmund Mach Research Foundation.

At Laimburg they toured the research facilities, field sites and wine cellar with viticultural researcher Florian Haas.

“It was a great experience and we were very lucky to have such accommodating hosts given that it was actually the middle of grape harvest while we were over there,” Harriet said.

Nadine, Harriet and Florian Haas from the Laimburg Research Centre.

The trip was supported by a Wine Australia travel grant and the CoSE travel grant scheme.