Phylloxera
1984
Disease found in Marlborough vineyards leading to the use of disease resistant root stock.
The first recorded instance of Phylloxera, a tiny louse, in Marlborough occurred on a vineyard where replacement plants were brought in from Nelson that had not been treated. Harvesting machines then spread the louse from vineyard to another vineyard and so on.
In the early twentieth century a botanist by the name of Charles Valentine Riley came to the rescue making a discovery that was to become the solution indefinitely. Riley grafted American Vitis Riparia rootstock onto European Vitis Vinifera creating a plant that had immune roots and drinkable fruit. The solution was found and in the majority all vines were replaced.
Grafted Phylloxera resistant vines do not produce better quality wine. They produce wine of lesser quality. The only time you would graft vines is when you have one or both problems – Phylloxera and /or nematodes. This is well documented in scientific literature.
Source
MEX and Marlborough museum wine display
Visited 6/04/23
https://www.altitudetours.co.nz/the-story-of-phylloxera/
https://www.theprow.org.nz/assets/files/Marlboroughs-Wine-Story-Wayne-Thomas.pdf