MS Topic of the Week 9/27/2019 - Master

Grassy booze discussion last week from and . Thanks gents!

This week: New threats of phylloxera

What regions are most recently affected by the louse and why? What are their plans of action? Is it all bad or is there a silver lining?

  • Washington is the most recent area (Walla Walla Valley in particular) confirmed by being affected with Phylloxera. Not entirely sure about the plan of action, since it is believed to have been in the area for some time, but  is confirmed now. There is a silver lining, due to the way it is being contained & can be further understood.

    Wine Enthusiast article

  • Victoria has discovered Phylloxera this year in March. Genetically identical to the bugs found in Yarra. The Aussies have a great communication method and plans in place for the louse - quite impressive once you dig in. There are exclusionary zones as well as protocols for materials in and out of the vineyard to reduce contamination and spreading. Love the "on farm bio-security" term. 

    Can you shed any light on this ?


  • One of the silver linings in Walla Walla is that many of the vineyards are about 40-50 years old and are approaching the age when they would start to be replanted anyway. Growers have the opportunity now to replant with phylloxera-resistant American rootstock and the timing of the discovery is not too disruptive.

  • Hey Nick!  Lots of fun stuff here. So the St. Andrews vineyard is within the Yarra Valley.  It sits in a part of the Yarra known as a Phylloxera Risk Zone (well, until now).   The Yarra is the most infected GI in Victoria, and Australia. Parts of it, especially the valley floor near Lillydale and Coldstream are all infected.  The upper Yarra is at risk, and vulnerable to poor hygiene practices. 

    There are quite a few at risk zones around Victoria. They are mainly centered around the south eastern portion of Victoria. I bottled a Micro Wines Pinot Gris this year with fruit from the Mornington Peninsula-a phylloxera at risk zone, but i process in Geelong-a phylloxera free zone.  I needed to do a few things. 

    1. My harvest bins needed to be spotless before fruit went into them. Once clean, they were kept on ground tarps during harvest.  
    2. When the truck arrived, i washed down its flatbed to make sure the bins would stay clean.
    3. A state inspector needed to be booked(at my expense) to meet me at the winery.
    4. When we arrived, he inspected every inch of each bin on the fork lift before they were allowed to touch the ground. 
    5. A lot of paperwork went a long with this process

    Geelong is phylloxera free (the last time it had phylloxera they burnt every single vineyard to the ground), and it needs to stay that way. 

    When working in the Yarra Valley, winery practices become paramount.  One essentially must assume that the winery, its equipment, the workers, and anything that passes through it is contaminated.  We were taking in fruit from all over the Yarra, as well as from the Strathbogie Ranges. 

    1. We setup a linear fruit receipt process. Trucks came at one end of the crush pad only,
    2. We would unload their bins, and then they would proceed to the sanitizing area.
    3. The Truck would be washed in accordance with the time and temperatures noted in the document you attached. 
    4. It would then be able to cross over into the phylloxera-free section of the crushpad, and then exit the winery. 
    5. Once fruit bins were emptied, they would receive the same treatment before going back out to another vineyard. 
    6. Anything or anyone that need to cross this line in the winery was hot washed or bleached. 

    I have found that the regions afflicted by phylloxera take the most care. Vineyard bio-security measures vary greatly across producers. When i visited Hill of Grace, our tour guide didn't ask us to step in a foot-bath to sanitize the bottoms of our shoes. And, he owned the vineyard!  At Bannockburn, the winemaker lovingly scrubbed the soles of my shoes with a bleach soaked wire brush. 

    I think Phylloxera will continue to spread slowly across the Yarra and its surrounding regions.  its impossible to kill it off at this point.  There are some natural boundaries that should protect western and northern Victoria.  Its South Australia that really needs to ensure their security.  We don't talk about high quality fruit produced from Cabernet or Pinot Noir vines, and those in Victoria and WA are not all that old. The old Grenache, Shiraz, Cinsault and Mataro vineyards of South Australia are one of the wine-world's great treasures, and they need to be protected. 

  • Another silver lining is that the grower now has the ability to select a specific rootstock for their specific site. While there is a lot of romance and history tied to own-rooted vines, and certainly that is a significant marketing angle to work, I'm not sure that own-rooted vines have even been conclusively proven to be better or worse than a selected rootstock. Most of the world's most expensive, sought after wines are on selected rootstock. 

    There are dozens (maybe even hundreds) of rootstocks to choose from, and new ones are still in development. For a grower who's replanting on American or hybrid rootstock, they can now select for a variety of issues besides phylloxera resistance: nematode resistance, drought tolerance, potassium uptake, vigor, ease of grafting, etc.  They will be able to choose a rootstock that can help mitigate other issues at the same time as preventing phylloxera.

  • Thank you so much for the time and effort in such a thorough response !!

  • I need to find these 50 year old Walla Walla vineyards. 

  • Thanks for all of this detail, Jon! So interesting.