The repercussions of the phylloxera outbreak which nearly destroyed wine in the way we think of it, continue to be felt to this day. Jamie Goode introduces the 19th century epidemic that was caused by a tiny yellow Aphid.
Biosecurity is a hot topic nowadays. If you get off a long-haul flight carrying one of your apples in your bag and be hit with a huge penalty if you don’t remove it prior to completing the customs. In the 19th century, however the apple was not a thing. Plants were transported – and with them , diseases and pests – all over the world.
It was the deficiency of awareness of the significance of biosecurity, along with the introduction of the steamship that nearly led to the end of the wine we recognize it today. What is the reason for the steamship? It was a way to ensure that the plants transported across continents from one to the next could arrive in a hurry so that any pests associated with them would have a greater chances of surviving the voyage.
Enter phylloxera. This aphid feeds on the vine’s roots that originate in North America. Based on the variety and the area it is also able to be found feeding on leaf. It coevolved here with native vines, and both grew next to each other without many issues. A good parasite doesn’t kill its hosts. After all, they have to find a place to stay. They do take a small amount however, less than. However, Vitis vinifera is the Eurasian grape vine that makes up most wine that is produced across the globe, has evolved without the help of this aphid. And when they came into contact, it was a conflict which resulted in the death from the grapevine.
How did phylloxera make its way into Europe and, from there, across the globe? This is the answer in a different disease that struck the wine industry that was powdery mildew. It also originated from the USA which arrived around the year 1850. Also is where native American vines are resistant to the fungal disease however when it came to Europe, Vitis vinifera was extremely vulnerable. One solution suggested was to cultivate resistant American vines, and they were sent to Europe. They brought along the phylloxera.
The first signs of a phylloxera outbreak were noted in the early 1860s in the Southern Rhone and the Douro Then, shortly thereafter in Austria. Since the first outbreaks it was a rapid spread and the final quarter into the nineteenth century witnessed the spread of phylloxera throughout the world of wine leaving behind an economic trail of destruction.
Recent genetic studies have revealed that there could have been two distinct outbreaks of phylloxera , which later expanded to all parts of the world of wine. The first and well-documented case – occurred located in south France The second occurred in an agricultural nursery in Austria. At the time that people were aware of the issue the infected plant material was already spread widely between these two places by viticulturists searching for solutions to powdery mildew.
The life-cycle that this bug goes through is complex however the harm it does is significant. When it suckers up the root system that is not protected the vascular system of the plant is damaged and they cease functioning. The vine then begins to decline that will result after a few years of dying. It is also believed that the damage to the feed exposes the roots to infection, which speeds up the demise of the vine.
It’s difficult to imagine the fear that would have been experienced during the time of wine-producing nations like France in which this beverage was a major part of the culture and economy. At the time, about one-sixth of the French state’s revenues were made by wine and one third of the population earned income from it.
It was up to Prof. Jules-Emile Planchon, a botanist chosen by the government commission set up to study the outbreak, to pinpoint the cause. He sifted through the rootstocks of an energizing plant and observed clumps and clumps insects with no wings happily eating their way through.
Phylloxera is a complex life cyclethat was only discovered after the disease had ended. As with many aphids is parthenogenetic. This means that it doesn’t require sex to reproduce. The form that grows roots settles on roots that are suitable and then punctures them using its mouthparts. It injects saliva and results in the roots cells to expand into a structure called galls, which increase the quantity of nutrients it has and also provides protection. It then lays eggs that hatch, and the resulting winged variants of the aphids move through the roots, then climbs the trunk , and then are carried up into the air. If they can find the right place to feed, they’ll continue to proliferate, and the population can grow rapidly. In certain regions, there are sexual forms of phylloxera, which develop on leaves. They also trigger gall formation and in this instance the protective structure that surrounds the feeding phylloxera is extended below the leaf and extends towards the leaf’s upper surface to let crawlers escape.
A variety of options were explored. Chemical defences were attempted but generally did not work (a horrible insecticide known as carbon bisulfide showed some effects when injecting into the roots, however it was only a small amount) floods of vineyards during the dormant season did not seem to work, and vineyards that were planted in soils that were sandy did not suffer. However, for the majority of vineyards that were not sandy and that couldn’t be flood-proofed it was a bleak prospect.
Click here for legacy of phylloxera.
One controversial option was offered. American vines that sheltered the invader in the first instance was naturally protected from the phylloxera. The places where they were planted they flourished, and everywhere else was the scene of destruction. Sure, the wines they made tasted pretty bad, but it was better than nothing even if it was not, said the side that supported this method that became known as the americanists. Wine tastings made with the American vinifera varieties were arranged however the sad conclusion was that the wine, with its distinctive taste, were not as good to the wines people were accustomed to drinking from vinifera varieties.
What are the implications of crossing between American vinifera and vine species? Could these crossbreeds bring the strength of the first with the quality of wine of the vinifera? The question was explored in an explosion of breeding efforts that resulted in what is now referred to as French-American hybrids. A few of them are very interesting, but they are not all alike with respect to their resistance against phylloxera they didn’t really catch on to the public. However, it was an interesting time in breeding vines.
Someone came up with an amazing idea. It was in 1869 that monsieur Gaston Bazille suggested grafting vinifera varieties onto American rootstock. With retrospect, this is to be a great idea, however at the time, there were many unanswered questions. Most important among them were the following. First, how long will the graft be in place? In addition, could the rootstock bring the American vinifera character to the vinifera wine by altering characteristics of the vinifera grapes by this unnatural union between stock and scion? In the third place what is the degree of resistance different rootstocks be? We already knew that certain American varieties were stronger against phylloxera, compared to other varieties.
The first recorded examples of this grafting technique was in 1874 at the time that Henri Bouschet displayed an Aramon (Vitis vinifera) vine that was grafted onto American rootstocks at the Congres Viticole at Montpellier. Within a few months, it was apparent that, albeit in a strange way the wine produced by vinifera vines that were grafted onto American rootstocks maintained all the characteristics of the vinifera variety , while benefitting from the phylloxera-resistant qualities that is characteristic of American roots. It was the perfect circle. The disease had originated in America however, so did the hope for salvation.
The idea was widely spread. The method of grafting was so simple to master that nearly everyone could do it. The availability of American grapevines was more of a challenge since many wine regions were beginning to ban imports to keep the remaining vineyards that were phylloxera-free from falling victim to the disease. But not all were attracted by the radical concept of transplanting. Some were against replanting, and the consequent loss of three years of production. They clung in fervently to chemical treatments. However, common sense prevailed , and the grafters took the day. The lengthy work of replanting phylloxera-devastated vineyards began. It wasn’t an easy procedure, and some of the more prestigious estates that were reluctant to cut down their vineyards, continued to treat them by applying insecticides as lengthy as it was possible. The decision of what material for grafting was further complicated due to being unable to some time to locate American vine varieties that were well-adapted to chalky soils that prevailed in some of France’s most important regions.
The effects of the phylloxera epidemic remain in the present. The primary impact was the alteration of the landscape of viticulture. If we take France for an instance, the area of vineyards decreased quite dramatically. Replanting also led to the fact the existence of a kind of viticultural bottle neck with traditional varieties being wiped out and being discarded in favor of more appealing commercially-oriented varieties. There are many regions where there is a desire to bring back the ‘lost’ varieties which were able to disappear in this replanting phase.It is One of the oldest methods to plant vineyards is called marcottage or layering, involves putting a still-attached vine into the soil so that it develops its own roots, relying on the mother plant, until it eventually becomes a distinct vine that is its own is no longer an appropriate choice. The reason for this is that the roots are vinifera and are therefore susceptible to the phylloxera. Before the crisis the majority of vineyards were planted in foule – basically randomly, without rows because of the continuous planting of canes and even trees – continuously revitalizing the vineyard without planting. Following the crisis, most wineries were planted with rows.
Additionally, the selection of rootstock, and its impact on the parameters of grafts, like vigor, was added as an additional variable, and an entirely addition to the toolbox for viticulture.
Certain areas have been spared from the phylloxera plague, and in these areas are still vines that are planted in their roots. The most well-known of these is Chile as well as South Australia, which have been able to stay free of the disease. Argentina as well as Washington State also have largely non-grafted vineyards. And while the phylloxera virus is prevalent in both, it does not appear to be a significant issue. This could be due to the soil’s structure, and in Argentina’s case , some have suggested that it’s due to the fact that much of the irrigation is done through regular flooding. Within Germany’s Mosel wine region, there are many vineyards ungrafted (again the soil appears to provide protection) in addition, the Douro has a renowned vineyard that was planted on its roots. Quinta Do Noval’s Nacional. The the New Zealand’s Central Otago wine region the oldest vineyards in the region that date from the 1980s, are not grafted (some are sagging, unfortunately) as well as many of Oregon’s oldest vineyards are planted on the roots of their owners (likewise they’re suffering).
For the last 130 odd years, there’s been a cease-fire. By grafting onto American rootstocks we can have wine, and it’s in a way, like it was. Both the roots as well as aphids coexist together in a certain equilibrium. What is the outlook for the future? What happens in the event that this balance becomes unstable, and a new form of phylloxera emerges which kills the vine? It’s pretty impossible.