CSU investigates sunburn in wine grapes

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Description

Charles Sturt University is investigating how to reduce browning, cracking, shrivelling and the resulting financial losses in Orange’s wine grapes, which can affect up to 15 per cent of the crop.

Justin Jarrett’s higher altitude grapes suffered worse sunburn than his lower altitude grapes during last year’s heatwave and he knew he had a problem. 

Mr Jarrett said sunburn created a “flabby” flavour in chardonnay grapes, while shiraz grapes started to taste like fruit cake.

“If you’re looking for a champagne base, you’re looking for that clear, crisp wine and so the flabby flavours that come from sunburn are not what we want,” he said. 

“Sunburn has become more prevalent in the last four or five years – last year there was no sunburn at 700 metres, high sunburn at 900 metres and really it should be the other way around because it’s hotter at 700 metres.”

On a sensitive, mature chardonnay grape, symptoms can appear within five minutes once the berry reaches 40 degrees Celsius.

Mr Jarrett pruned leaves late, while others who pruned earlier suffered less damage.

CSU’s Dr Joanna Gambetta from the National Wine and Grape Industry Centre is conducting the research, testing three pruning methods – none at all, December at the end of flowering and mid-January.

“We’re trying to get guidelines to help farmers do it in the best way possible,” she said.

Period09 Jan 2019 → 25 Jan 2019

Media coverage

4

Media coverage

  • TitleCSU investigates sunburn in wine grapes
    Degree of recognitionNational
    Media name/outletWin News Central West
    Media typeWeb
    CountryAustralia
    Date25/01/19
    DescriptionWHEN you combine heat, harsh light and ultraviolet radiation, people aren’t the only ones to cop sunburn.
    Charles Sturt University is investigating how to reduce browning, cracking, shrivelling and the resulting financial losses in Orange’s wine grapes, which can affect up to 15 per cent of the crop.
    Justin Jarrett’s higher altitude grapes suffered worse sunburn than his lower altitude grapes during last year’s heatwave and he knew he had a problem.
    Mr Jarrett said sunburn created a “flabby” flavour in chardonnay grapes, while shiraz grapes started to taste like fruit cake.
    “If you’re looking for a champagne base, you’re looking for that clear, crisp wine and so the flabby flavours that come from sunburn are not what we want,” he said.
    “Sunburn has become more prevalent in the last four or five years – last year there was no sunburn at 700 metres, high sunburn at 900 metres and really it should be the other way around because it’s hotter at 700 metres.”
    On a sensitive, mature chardonnay grape, symptoms can appear within five minutes once the berry reaches 40 degrees Celsius.
    Mr Jarrett pruned leaves late, while others who pruned earlier suffered less damage.
    • READ ALSO: Killing European wasps set to be an inside job
    • READ ALSO: Organisers thrilled with wine festival
    • READ ALSO: Wine businesses clean up at tourism awards
    CSU’s Dr Joanna Gambetta from the National Wine and Grape Industry Centre is conducting the research, testing three pruning methods – none at all, December at the end of flowering and mid-January.
    “We’re trying to get guidelines to help farmers do it in the best way possible,” she said.
    URLhttps://www.facebook.com/watch/?v=2422766607952724
    PersonsJoanna Gambetta
  • TitleProtecting wine grapes from sunburn
    Degree of recognitionNational
    Media name/outletThe Land
    Media typeWeb
    CountryAustralia
    Date24/01/19
    DescriptionHigh temperatures, harsh light and ultraviolet radiation can lead to a nasty case of sunburn – not just for people but for winegrapes – and Charles Sturt University (CSU) is investigating how to reduce the damage and financial losses.
    The project by CSU postdoctoral researcher Dr Joanna Gambetta from the National Wine and Grape Industry Centre (NWGIC) has been funded by Wine Australia’s Incubator Initiative.
    “Sunburn can affect up to 15 per cent of winegrape berries in Australia in any given season,” Dr Gambetta said.
    “The browning, cracking and berry shrivelling means that yields are reduced and the fruit can be downgraded, causing significant economic losses to growers and wineries.

    “On a sensitive, fully mature Chardonnay grape, symptoms of sunburn can appear within five minutes once surface temperature on the berry reaches an ambient temperature of 40 to 43 degrees celsius.”
    Dr Gambetta said sunburn of grape berries was influenced by a number of factors, including grape variety, the stage of development, water stress and canopy management.
    “Grape growers can remove leaves from the vine to aid in disease management and my research aims to identify the optimum time for leaf removal to balance disease reduction and sunburn, as well as determining how altitude affects the degree of sunburn,” Dr Gambetta said.
    Experiments in vineyards in Orange are examining three different timings of defoliation of Chardonnay berries: a control group where leaves are not removed at all; a second group where leaves were removed at the end of flowering in December; and a third group of vines where the leaves will be removed at véraison (mid-January), when the sun will be at its fiercest and the grapes at their most vulnerable.
    “The aim of the research is to develop a set of guidelines for growers to reduce the impact of sunburn damage to their grapes,” Dr Gambetta said.

    Wine Australia’s general manager research, development and extension Dr Liz Waters said the research, while focussed on New South Wales, had much broader implications as sunburn was a potential problem in a number of regions.
    The focus of this research through Wine Australia’s Incubator Initiative was developed from the priorities identified by
    Wine Australia’s Regional Program partners in NSW to support growers in finding locally tested solutions to industry problems.
    The NWGIC is an alliance between CSU, the NSW Department of Primary Industries (DPI) and the NSW Wine Industry Association.
    URLhttps://www.theland.com.au/story/5841966/protecting-wine-grapes-from-sunburn/
    PersonsJoanna Gambetta
  • TitleCSU investigates sunburn in wine grapes
    Degree of recognitionNational
    Media name/outletCentral Western Daily
    Media typeWeb
    CountryAustralia
    Date09/01/19
    DescriptionWHEN you combine heat, harsh light and ultraviolet radiation, people aren’t the only ones to cop sunburn. 
    Charles Sturt University is investigating how to reduce browning, cracking, shrivelling and the resulting financial losses in Orange’s wine grapes, which can affect up to 15 per cent of the crop.

    Justin Jarrett’s higher altitude grapes suffered worse sunburn than his lower altitude grapes during last year’s heatwave and he knew he had a problem. 
    Mr Jarrett said sunburn created a “flabby” flavour in chardonnay grapes, while shiraz grapes started to taste like fruit cake
    “If you’re looking for a champagne base, you’re looking for that clear, crisp wine and so the flabby flavours that come from sunburn are not what we want,” he said. 
    “Sunburn has become more prevalent in the last four or five years – last year there was no sunburn at 700 metres, high sunburn at 900 metres and really it should be the other way around because it’s hotter at 700 metres.”
    On a sensitive, mature chardonnay grape, symptoms can appear within five minutes once the berry reaches 40 degrees Celsius.
    Mr Jarrett pruned leaves late, while others who pruned earlier suffered less damage.
    READ ALSO: Killing European wasps set to be an inside job
    READ ALSO: Organisers thrilled with wine festival
    READ ALSO: Wine businesses clean up at tourism awards
    CSU’s Dr Joanna Gambetta from the National Wine and Grape Industry Centre is conducting the research, testing three pruning methods – none at all, December at the end of flowering and mid-January.
    “We’re trying to get guidelines to help farmers do it in the best way possible,” she said. 
    URLhttps://www.centralwesterndaily.com.au/story/5843137/sun-not-fun-for-wine-grapes-as-csu-searches-for-solution/
    PersonsJoanna Gambetta
  • TitleResearchers look to protect wine grapes from sunburn
    Degree of recognitionNational
    Media name/outletThe Rural
    Media typeWeb
    CountryAustralia
    Date09/01/19
    DescriptionIf there is one thing Aussies know, it’s that we need to use sun protection, but it is not just people that can be burned.
    High temperatures, harsh light and ultraviolet radiation can lead to a nasty case of sunburn not just for people but for wine grapes – and Charles Sturt University is investigating how to reduce the damage and financial losses.

    The project by CSU postdoctoral researcher Joanna Gambetta from the National Wine and Grape Industry Centre has been funded by Wine Australia’s incubator initiative.
    “Sunburn can affect up to 15 per cent of wine grape berries in Australia in any given season,” Dr Gambetta said.

    “The browning, cracking and berry shrivelling means that yields are reduced and the fruit can be downgraded, causing significant economic losses to growers and wineries.
    “On a sensitive, fully mature Chardonnay grape, symptoms of sunburn can appear within five minutes once surface temperature on the berry reaches an ambient temperature of 40 to 43 degrees.”
    Dr Gambetta said sunburn of grape berries was influenced by a number of factors, including grape variety, the stage of development, water stress and canopy management.
    “Grape growers can remove leaves from the vine to aid in disease management and my research aims to identify the optimum time for leaf removal to balance disease reduction and sunburn, as well as determining how altitude affects the degree of sunburn,” Dr Gambetta said.
    Experiments in vineyards in Orange are examining three different timings of defoliation of Chardonnay berries: a control group where leaves are not removed at all; a second group where leaves were removed at the end of flowering in December; and a third group of vines where the leaves will be removed at véraison (mid-January), when the sun will be at its fiercest and the grapes at their most vulnerable.
    “The aim of the research is to develop a set of guidelines for growers to reduce the impact of sunburn damage to their grapes,” Dr Gambetta said.
    Wine Australia’s general manager research, development and extension Liz Waters said the research, while focused on NSW, had much broader implications as sunburn was a potential problem in a number of regions.
    URLhttps://www.therural.com.au/story/5842238/researchers-look-to-protect-wine-grapes-from-sunburn/
    PersonsJoanna Gambetta

Keywords

  • sunburn
  • wine grapes