When A Genetic Solution Saved The French Wine Industry

The mid to late 1800s was a very difficult time for the European wine grape industry.  New pests associated with native North American grape species made their way to the "Old World" because of transport between the continents.  I recently wrote about how a fungal disease called downy mildew nearly destroyed the industry until it was saved by the accidental discovery of an effective chemical fungicide.


In today's post I'm going to talk about an insect pest that was introduced to Europe in the same era.  It was a a root feeding relative of aphid called Phylloxera.  Native American grapes are quite tolerant to it, but when it started attacking the roots of the European, Vitis vinifera grapes it began debilitating and finally killing the vines.  It may have arrived in the 1850s, but was first recognized in 1863.  This was an extremely trumatic economic and social crisis.  More than 1 million hectares of vines were killed and many more debilitated before a solution was finally found. In this case the ultimate solution was found via genetics  (There are many good sources about the extended drama and real economic suffering associated with this this crisis - see links below)

1888 drawing of what is now classified as Daktulosphaira vitifoliae

The Genetic-based Technology Solution

The solution to Phylloxera that was ultimately applied seems obvious with hindsight.  Since the North American grape species had always tolerated this pest, why not use them as "rootstocks" and graft the revered European varieties on top of them?  Grafting of desired varieties onto the roots of less desirable, but either more hardy or already established versions of the same crop was not a new idea.  That had been practiced for thousands of years for many tree and vine crops.  The ancient Hebrew and Christian scriptures are full of literary images based on the concept of grafting.  It was an ancient, practical solution - but what it amounted to was a rather dramatic "genetic modification" of the roots of millions acres of European grapes (and eventually grapes around the world).

This idea of grafting onto foreign, low quality grapes was hard to swallow for much of the French wine community of the day.  Their questions included:

• Will treasured, traditional varieties like Pinot Noir grafted on this inferior sort of grape still make a classic red Burgundy worthy of each specific appellation in that district?  
• Will this new reality mess with the quality that was traditionally achieved with complex blend of varieties in a region like Bordeaux?
• Will this new pest eventually overcome this solution?  
• Should wine made from grapes grafted on American rootstocks be labeled as GMO?

Ok.  They didn't ask the last question in the 1800s, but there was a long-running and eventually meaningless debate about whether pre-Phylloxera wines were better.

An Ironic Modern Rejection of a Genetic Save for Grapes

Flash forward to modern times.  There is a nematode pest which spreads a grape disease called Fanleaf Virus.  Once the soil on a given site has been contaminated with that small, roundworm parasite and the virus, if you plant vines there, even after ten years with no grapes, after a few years they decline and die.  This is actually a problem nearly as old as Phylloxera, but fortunately it does not spread easily.  Once people understood how it works, it has been mainly limited to certain areas in France, some other European countries, and a few places in California.  The sad part is that there are significant hectares of vineyard sites in premium wine growing districts that can't be used to make great wine because of this issue.  For many crops, one can just move away from such problems, but for wine the unique combination of climate and soil can create conditions which are legitimately important for quality.  The term "Terroir" is used to describe that essence of place.  Fanleaf virus and its vector severely compromise the Terroir wherever they occur.

With the advent of biotechnology there was the possibility of a better solution for Fanleaf contaminated sites that never existed before (there were some nematode resistant rootstocks but they were undesirable for other reasons).  A rootstock was developed which was resistant to the virus using the same approach that saved the Hawaiian papaya industry.  With that genetic solution, high quality grapes could be successfully grown on on compromised sites in a way directly analogous to how American grape rootstocks saved the crop from Phylloxera in the 1800s.

One might imagine that with the tremendous esteem for terroir in the wine French wine industry, this means of rehabilitating highly valued vineyard sites would be eagerly embraced by the wine industry. Unfortunately that was not the case.  There were some modest field tests of this rootstock being conducted by a French governmental agency in 2010.  There was a great deal of public controversy about this, little industry defense, and ultimately activists destroyed those trials on August 15, 2010.  Their stated concern was that this new rootstock could "genetically contaminate" the rest of the grape crop.  Let me explain why that fear was irrational to an absurd degree:

As this post describes, back in the late 1800s, the entire French and European grape crop was replanted on American rootstocks which differ from the Vitis vinifera grapes by probably hundreds of genes or versions of genes.  No one has ever needed to worry about "genetic contamination" from those millions of acres of genetically "foreign" rootstocks even though they have been present for over 100 years.  If those industry-saving American rootstocks (which are normally only underground) ever happened to get the chance to flower and generate pollen, it still wouldn't matter because grapes are never grown from seed. They are always grown from cuttings or buds.  That is also why you can plant blocks of different grape varieties side by side with no issue of "contamination."  So why would rootstocks with ONE very useful gene inserted by genetic engineering suddenly be a contamination risk?  There was absolutely no risk!

As far as I can tell, the grape industries in France and elsewhere were sufficiently intimidated by the magnitude and ferocity of the irrational response to have decided to simply live with some of their best vineyard sites being compromised. If someone in those industries knows differently, please let me know.

You are welcome to comment here and/or to email me at savage.sd@gmail.com.  I tweet about new posts @grapedoc

grape image mine
Phylloxera drawing from Wikimedia Commons

There are many websites which describe this traumatic event for the European grape industry and for the economy as a whole (Wikipedia: Great French Wine Blight, a review of what sounds like an interesting book about this by Christy Campbell,  a nice summary from 1986 in Wine Tidings republished  by The Wampum Keeper).

When A New Technology Saved The French Wine Industry

Amy Harmon's excellent, recent article in the New York Times describes how the Florida orange juice industry may soon be wiped-out because of a new bacterial disease spread by an introduced insect.  It looks like there could be a technology-fix for the problem using genetic engineering.  The question is whether the growers will get to apply that solution.

Coffee Rust - later these infected leaves fall off

The sort of crisis situation now facing the Florida orange industry is not at all unique in the history of farming.  There have been many times when some new pest  threatened the economic viability of a major crop.  Sometimes the pest "wins" and a particular farming industry simply goes away.  In the mid 1880s when Coffee Rust made it from Africa to the coffee plantations that supplied England from Java and Sri Lanka, the industry collapsed, and so the English had to switch to tea to get their caffeine.  When Wheat Stem Rust made it too hard to grow wheat in the Southern colonies of what would later become the US, the farmers shifted their cropping to cotton and tobacco.  That involved much higher labor requirements which in turn lead to the sad institution of slavery in that region.

But there have been other times when some new technological breakthrough has saved a threatened crop, as it possibly could for the Florida orange growers.  I'll give just one example here.

Back in 1874, a plant scientist name Pierre Millardet was walking down a road in Bordeaux France.  The famous vineyards he was passing were being devastated by a fungal disease called downy mildew.  It had been unwittingly brought across the Atlantic by the British who came back with specimens of the wild grape species they found in North America (e.g. Vitis labrusca - Concord types).  Those grapes harbored the downy mildew which was not too problematic for them, but the Vitis vinifera grapes of the Old World were extremely susceptible.  The wet climate of Europe was also ideal for fostering the fungal epidemic.

Grape downy mildew symptoms. Later leaves fall off.  Fruit can be effected too

Millardet was very concerned about this problem as were all the French looking at the possibility of not continuing to be able to produce wine.  As he walked past vineyard after vineyard nearly defoliated by the disease, he came upon one small part of a vineyard that looked remarkably healthy.  He quickly sought out the owner to ask why those vines looked so good.  It turned out that the grape grower had been frustrated by the fact that so many passer-bys on the road would help themselves to his grapes as they ripened.  He had concocted a mixture of copper sulfate and hydrated lime and sprayed it on the grapes to make them less attractive.

What the Bordeaux mix looks like sprayed on tomato leaves

By accident the farmer had developed a reasonably effective fungicide.  Millardet promoted that option, and soon the "Bordeaux mix" saved the French and other European grape industries.  It also saved the European potato crop which was also being devastated by a related disease that belatedly followed the potato from its origins in the Andes and caused the epic Irish Potato Famine.

Fortunately today we have many superior fungicide options to protect these crops.  Copper-based fungicides were "state of the art" in the 1870s, but by modern standards they are rather toxic to mammals, persistent in the environment, and bad for aquatic invertebrates.  One of their remaining uses is for organic farming which has only a few fungicide options that qualify as "natural."  New, synthetic fungicides that protect grapes, potatoes, wheat and other crops in Europe and elsewhere are far better for health and the environment. Still, without the accidental discovery of the "Bordeaux Mix," the European wine grape industry could have disappeared.

I gave an invited talk for the Specialty Coffee Association and its annual symposium back in February. The Arabica coffee growers in the highlands of Central and South America are facing a severe, new threat from a disease called coffee rust.  My role at the the conference was to put that crop threat into a global and historical perspective.  This grape disease story is one of the examples in my talk titled: "Humans vs Pests, The Long View."

You are welcome to comment here and/or to email me at savage.sd@gmail.com.  I tweet about new posts @grapedoc

Orange grove image from USDA-ARS
Coffee Rust (Hemileia vastatrix) image from Smartse
Grape Downy Mildew (Plasmopara viticola) image from the University of Georgia Photo Archive
Bordeaux mixture residue image from the Tomato Lover blog