Michael Fridjhon: Why isn’t SA doing more about leaf-roll virus?

By , 26 April 2016



I recently returned from a trip to Spain where I spent a couple of days at the Salon de Gourmets, one of the oldest and most respected of the curated luxury food and wine fairs. Amongst my discoveries was the extent of ancient vineyard in the Iberian peninsula. Producer after producer in regions like Toro, Rias Baixas and Bierzo showed wines which came from seriously old vines – fifty year old being pretty much the norm, century old not uncommon and in at least one case I happened upon an authenticated 18th century vineyard. All of the really old vines were ungrafted and had only survived because the regions in question were phylloxera free, mainly on account of their sandy soils.

Old vines are not a guarantee of better wine, though empirical evidence from the more established appellations of France suggests that there is a significant correlation between the age of the vine and the quality of the wine produced from its fruit. An interest in old vines is therefore not simply a matter of antiquarian concern, or a special kind of nostalgic indulgence. Rosa Kruger, probably South Africa’s most thoughtful viticulturist, has spent several years discovering, identifying and documenting old vineyards of the Western Cape. Her Old Vines project is largely a labour of love: winemakers like Eben Sadie are able to make use of the information she has assembled, and in that way produce a tangible result. However, the ultimate beneficiaries are the often impoverished vineyard owners, as well as the wine drinkers who get to sample the sometimes extraordinary wines made from the grapes.

A tell-tale sign.

A tell-tale sign.

Since there is only one way to get old vines – and that is with the elapse of time – it’s clear that if a young vineyard produces decent fruit, it might be worth maintaining and preserving in anticipation of even better quality in the years to come. And here’s the rub: very few of our modern vineyards are destined to make old age – simply because leaf-roll virus is still ever-present in our vineyards. It makes sense to record Neal Martin’s comments in his South African Report for Robert Parker, written in 2011 just after his first visit to South Africa, where he had been a judge at the Old Mutual Trophy Wine Show:

“We must broach the subject of endemic leaf-roll virus. Its effects are particularly felt during difficult growing seasons when it can prevent grapes from achieving full maturity, ostensibly accentuating the lows of a bad vintage. Much like phylloxera, it afflicts even the most prestigious vineyards ….

Leaf-roll virus is a complex issue. The prevailing thought appears to have been: “We just have to live with it.” One or two viticulturalists actually welcomed leaf-roll as effectively countervailing over-ripeness, a useful weapon to mitigate against global warming. Ignoring the issue is not going to make it go away and whilst leaf-roll does not preclude a producer from creating excellent wines every vintage, it detracts from the perception of South Africa as a world-class wine-producing country. But at least producers have moved on from a state of denial.”

So there are a few issues: how extensive is the problem, how much of a problem is it for producers, consumers, Brand SA and finally, is the solution worth what it might cost. The first is easy enough: leaf-roll virus is widespread, and while the situation is significantly better than it was 20 years ago when I was chairman of the Wine Industry Trust and I committed the bulk of our research budget to addressing the problem, there’s no guarantee that the “virus-free” planting material coming from the nurseries is what it purports to be. This imposes added obligations on the growers, many of whom send their stokkies for expensive batch-testing. I have a theory that the failure of the industry to address the issue sooner has everything to do with the KWV’s domination of the vine supply chain up to the 1990s. Whenever I raised the issue at the Trust it was clear that the KWV contingent (and their cronies in research and viticulture) wanted the problem to be seen as the malice of nature – something essentially beyond their control. We know empirically that producers who are determined to have virus-free vineyards can achieve this nirvana – starting with ELISA-testing of vines and rootstocks and then with individual vine removal the moment the first signs of virus appear.

If everyone did this, the nurserymen would find themselves black-listed for distributing defective material and the vineyard vectors (notably mealy bug and farm implements) would have fewer contaminated vines from which to spread the disease. However, it takes real commitment, but then the problem can be addressed: ask anyone from New Zealand where vineyard virus, which used to be a major issue a few decades back, has almost vanished.

The benefits to the industry would be enormous: less frequent replantings would substantially reduce the capital expenditure the growers are forced to make when their fruit is too contaminated to be properly saleable. Wine quality would improve dramatically: the stressed fruit character of wine from virused vines may not be evident to everyone, but competent buyers can pick it up immediately. We would have substantially greater tracts of older vineyards – and we would benefit from the enhanced complexity which properly mature vineyards are capable of imparting. Finally as Neal Martin has pointed out, there would be benefits for Brand SA.

So why aren’t we doing more about it: firstly because as things stand the management of the problem remains an individual initiative: it’s not treated like foot-and-mouth disease, even though, in viticultural terms, it is a problem of the same order of magnitude. Secondly, many of the people who are in a position to manage the protocols which should be established to address the problem are in some way conflicted. Finally, inertia usually triumphs when short term costs loom larger than long term benefits. If the vines were dropping dead overnight, the growers would get off their butts and treat it as the crisis it undoubtedly is. But they still get a crop, and they can still sell it. Until we vote with our wallets – all of us, not just the grumpy few – there’s no reason to expect a dramatic change to the status quo.

  • Michael Fridjhon has over thirty-five years’ experience in the liquor industry. He is founder of Winewizard.co.za and holds various positions including: Visiting Professor of Wine Business at the University of Cape Town; founder and director of WineX – the largest consumer wine show in the Southern Hemisphere and chairman of The Old Mutual Trophy Wine Show.


5 comment(s)

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    Davey | 2 May 2016

    Fridjhon fudging the facts again. It’s nearly a quarter century since the KWV had a role to play in the supply of nursery vines. To blame them, even in part, for the current situation is laughable. The fault lies with the wider industry. You really need to get off your anti-KWV hobby-horse and show a little more objectivity, Michael.

    Rosa Kruger | 30 April 2016

    Hi Michael, Thank you for the article which highlights the leafroll disease, one of the 2 most pressing issue in our industry, the other being low prices for quality grapes.

    May I please say the following:

    1. Leafroll has a devastating effect on the quality of wine

    2. We should never accept it as part of our future and it must absolutely be regarded as the “foot and mouth disease” of viticulture

    3. We have come a long way in our knowledge of combating the spread of leafroll virus in the last 10 years. Unfortunately not many winegrowers are committed to eradicating the disease.

    4. The reason for this laissez-faire attitude to the disease goes to the heart of a much bigger problem – there is no culture of good viticulture in our country, we are much more focused on winemaking and producing volume. We notice a downward spiral of this on many farms, partly caused by the ultimate low prices paid for quality grapes.

    Some farms have decided about 10 to 15 years ago to eradicate leafroll and start fresh. I know of Vergelegen and L’Ormarins. L’Ormarins has adopted a protocol that has kept the vineyards on the estate almost 100% clean during the last 11 years. It can be done.

    Prof. Gerhard Pietersen has done valuable work in this regard and has laid down the law in the war against leafroll. But not many buyers are demanding that the vineyards they harvest their grapes from be clean of leafroll and not many farmers follow these rules.

    There was a time when the nurseries unfortunately did not pay enough attention to propagating clean material – especially in the boom period around the 1990’s.

    Since then some nurseries have taken great effort in only supplying virus free material, Vititec for one. A strict grading system exists in the form of the VIA certification Scheme. In this system a farmer can order “blue label” material which is guaranteed “free of all known viruses”. But many farmers plant “white label” uncertified material which is not guaranteed clean.

    Once a farmer has planted this “clean” material, it’s up to him to keep it clean. There are prescribed rules to follow (Mealybug protocol) to achieve this. These rules are not difficult to adhere to, but it takes an absolute determination to apply them.

    Vititec has started a program of massal selection of some of our oldest blocks in SA. Most of these blocks were chosen not only because of their old age but also because they produce a great wine. We have taken cuttings in winter and the nursery is now propagating new, virus-free material from these blocks in a commitment to produce clean vines that come from vineyards that are expressing the South African terroir at its best.

    New varieties and clones are presently being imported by Vititec and other nurseries like Lelienfontein. This new planting material will be guaranteed free of leafroll virus.

    But it is still up to the farmer to keep his vines clean … And it is still up to our industry to show a greater commitment to viticulture and laying down the law in the eradication of this devastating disease.

      Rudy | 2 May 2016

      Rosa, thank you for this response. This issue has been front of mind for a long time for me. Can I ask for your thoughts on this question- is it possible for a producer to combat virus in virus free, replanted vines when neighbours on all sides have heavily virus affected vineyards?

        Rosa Kruger | 3 May 2016

        Dear Rudy.

        Good question, difficult situation.

        Releasing natural predators to combat mealybug helps when your neighbours have leafroll virus but it will still be difficult to stop your vines from getting the virus when your neigbours are not clean of mealybug and virus. Natural predators might fly over to your neighbour’s vines and feast on the mealybug in his vines and stop it from spreading to you.

        In designing the layout of your new vineyards, its always advisable to have a corridor between you and your dirty neighbour, but that’s not always possible.

        Ideally it should be an area (or industry!) driven initiative to fight leaf roll disease.

        (A windbreak might help a little to stop the wind blowing dying leaves with mealybug into your vineyards. Mating disruption also an option, but I am not sure of the success of it yet.)

    Dana Buys | 28 April 2016

    Michael, you are spot on. We are in the process of ripping 3 vineyards established at Vrede en Lust nearly 20 years ago. They should have been in their prime now, but very the poor quality planting material supplied in the late 90’s has ensured they become firewood instead on top producing vines. We ripped out 5 ha of badly virus infected Cab vinyards 7 years ago at age 10-11 years. Its hard to make vineyards profitable in such an environment.

    There is no way we as a nation can produce top quality grapes with poor planting material. In any other industry law suits would have ensured this does not re-occur.

    Its time the vineyard owners start holding the nurseries properly accountable.

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