Virus-Free Vineyards – The Blog

See you at Grape Day!

New Zealand Winegrowers’ Virus Elimination Project has just completed its final season of trials in Hawke's Bay and Marlborough, with monitoring and data collection complete and analysis under way.

Our Marlborough presentation has been incorporated into this year's Grape Day technical session, which will be held in Blenheim at the Convention Centre on Wednesday 10 June.

The 2015 programme is now available, and you can register online at http://grapedays.co.nz/. Marlborough presentations will also be videotaped and posted on nzwine.com for access by members.

Seasonal toolkit for managing leafroll 3

March is the best time to monitor red varieties for the visual symptoms of infection from leafroll 3 virus. This year, growers have an additional tool to help with the job.

New Zealand Winegrowers’ Leafroll 3 App, launched in 2014, enables you to take a photo of leaf symptoms in your vineyard (using your smartphone’s camera) and send it to the Virus Elimination Project team for verification. The app is available for free and can be downloaded from the iPhone and Android stores.

The app also provides you with links to the popular Flickr photo library, which shows Leafroll 3 symptom expression on individual varieties, including:

  • Pinot Noir
  • Merlot
  • Cabernet Sauvignon
  • Syrah
  • Malbec

Sports and spots for survey

Assessing the level of virus infection across New Zealand vineyards is the subject of Arnaud Blouin’s doctoral research – and he’s looking for industry participation during the run-up to vintage 2015.

Arnaud, a senior staff member at Plant & Food Research Ltd in Auckland, is conducting a survey of grapevine viruses already present in the country as part of his studies at the University of Auckland. He also hopes that growers and viticulturists will contact him if they spot unusual symptoms in the vineyard during the period from February to April. 

This Sauvignon blanc leaf was tested and shown to be free of Leafroll 3 Virus despite showing typical symptoms.

Symptoms of interest include:

  • Leaf distortion, leaf spots, leaf scorch or unusual leaf colouration (early yellowing or reddening, for example)
  • Extremely low vigour
  • Unusual branching or uneven wood maturation on canes
  • Early leaf drop
  • Graft incompatibility symptoms

‘The symptoms may be an indication of infection from one or more grapevine viruses, which can be identified using laboratory diagnostics,’ observes Arnaud. ‘Some viruses might be harmless but the goal of my survey is to learn as much as possible about their presence and impact – and growers can help with that.’

Arnaud is the current recipient of New Zealand Winegrowers’ Rod Bonfiglioli Scholarship, and he is working closely with team members from the Virus Elimination Project to stop the spread of Grapevine leafroll-associated virus 3 in New Zealand vineyards. You can read more about his research in the current issue of New Zealand Winegrower magazine.

If you'd like to report unusual symptoms, you can contact Arnaud by email at  

About

Welcome! This blog is maintained by members of the Virus Elimination Project, a New Zealand Winegrowers' Research Project that is co-funded by the Ministry for Primary Industries (Sustainable Farming Fund).

The Virus Elimination Project has three main objectives:

  1. Identify and map the presence and/or spread of Grapevine Leafroll-associated Virus 3 (Leafroll 3) in participating vineyards in New Zealand.
  2. Contain and control Leafroll 3 virus and the main vector – mealybugs – through a programme that comprises vine removal/replants, hygiene practices and insect control.
  3. Develop “best practice” guidelines for New Zealand Winegrowers, with the long-term goal of maintaining virus-free vineyards.

Control and management of Leafroll 3 is a community issue. That’s why the project trains growers to identify leafroll virus, map, treat, and remove infected vines on an area-wide basis in tandem with effective control of mealybugs. We welcome your comments and questions on this blog.

Click here to read disclaimer.

Categories

Fact Sheets