But that’s not the only problem caused by the leaf roll virus on their Chardonnay vines. It’s made worse by the presence of mealy bug, which is thought to have been spreading the virus from Peabody and Smith’s Craggy Range Chardonnay vines grown on the Gimblett Gravels, onto their red grapes.
“We started to see an increase of mealy bug around our Chardonnay vines in 2009 and we believe it was being spread mostly downwind onto the red grapes, which is why we now have to remove these vines. It’s been on the Chardonnay at a very low level for the past 10 years but in the early days it wasn’t affecting the quality of our Chardonnay (Les Beaux Cailloux – ‘the beautiful stones’) at all; the wines were becoming better each year,” Master of Wine Steve Smith says.
The big trouble began when the virus started infecting the red grapes on the vineyard.
“We cannot put them at risk, so that’s why we’re pulling out the Chardonnay, which has been a heart-wrenching decision for me but a hugely financial one for Terry Peabody because it’s a really big cost,” Smith says.
The spread of the virus is not the only thing that’s changed in the past 10 years; the technological ability to identify leaf roll virus has grown too. Known as Eliza technology, it has become more accurate and cheaper to identify exactly where leaf roll virus is affecting grapevines today.
The heart breaking aspect of this vine pull for Smith is that it means starting all over again with new plantings of Mendoza Chardonnay.
The latest Craggy Range Les Beaux Chardonnay 2010 is now made from grapes grown on 11 year old vines and Smith says he saw a big qualitative difference when the vines were 10 years old; compared to when they were first planted.
The 2011 Les Beaux Cailloux will be the last made from these vines before nearly all of them are pulled out. Production each year wavers from between 400 to 650 cases of Les Beaux Cailloux and there is a parcel of clone 95 Chardonnay which will remain; once the vines are mature, the grapes they yield will be contenders for Les Beaux Cailloux again.
The reason leaf roll virus was noticed so strongly on these vines is the impact it has on the colour and flavour of red grapes, says Smith.
“It’s a huge problem on our top quality red grapes because it reduces sugars. We can’t take that risk. For grapes like Sauvignon Blanc, people don’t worry about it as much in the short term because it tends to reduce sugars and lower sugars are not a worry with that variety, although it seems circumstantially that mealy bug is getting more established around the country and that is a problem.”
The financial blow, risk of disease spread and threat that the growth in mealy bug virus potentially pose are all cause for alarm, says Smith, who laments an ever bigger problem still for a country with vineyards as young as New Zealand’s are: “It’s a real worry when we’re trying to gain a wealth of older vines around the country and this virus means we’re losing some of our best.” ν
