Hi everyone, this week's topic is vineyard focused: Phylloxera.
What major winemaking country has not been invaded by phylloxera? Name some reasons why this country and other wine regions may have avoided the louse.
After poking around a few sites, here are some of the possible reasons:
1) Chile is extremely isolated with the Pacific Ocean on the West and the Andes Mountains to the East.
2) The government and in particular, the agency known as the Quinta Normal Agriculture, actively works to ensure that infested vines are not brought in from other countries.
Chile also benefited from the importation of pre-phylloera era European grape varieties in the 1830s.
Some other regions have been maintained in such a way that the disease is contained and a number of vineyards can feel comfortable using the natural rootstock.
- Louse does not grow enough to make use of it's wings, limiting the spread
- Flood irrigation is common and can be used to drown them if needed
- Victoria was the most hit by the bug, but several states remain Phylloxera Exclusion Zones, including Western Australia, South Australia, Northern Territory and Tasmania.
- Working on bringing all the states up to a national standard, as proposed by the following document held as the industry standard for managing the spread of phylloxera. http://www.vinehealth.com.au/media/National-Phylloxera-Management-Protocol.pdf
Primary source: The Wine Bible
Even just the word "phylloxera" conjures up so many emotions of "what could have been" in regions all over the world. This little louse was imported from America to France on infected rootstock in the 1860s and claimed over 2.5 million HAs.Chile has two major reasons for remaining Phylloxera-free: it has incredibly strict importing and customs regulations, and it is geographically bounded and shielded by the Atacama Desert, the Pacific Ocean, and the Andes Mountains. Additionally, some areas of Western and Southern Australia remain Phylloxera-free. Finally, sandy soils, such as those found in Portugal provide roots with natural resistance to this little bugger!
Makes me want to use the hashtag #NeverAgain :)
Sourced from Robinson's Encyclopedia and the GuildSomm guides.
Regarding soil, the louse particularly likes dense, moist soils in cooler climates, which is why France was a perfect breeding ground. As Westley said, sandy soils (not dense and drains really well) are not susceptible to infestation. Interestingly, the slate soils found in the Mosel have remained phylloxera free. Regardless, Germany has implemented policies to only allow planting grafted resistant rootstocks anyway.