Resistant grape varieties : are there the ecological future of vineyards ?
Two methods mainly exist today to fight against vineyard diseases:
- Using chemical products to eradicate the pathogen (mushroom, larva, butterfly, etc…)
- Using various growing methods allowing vines to fight more efficiently against these external attacks: ground covers, crushing of vine shoots, etc ... which bring nutrients to the vineyard, reinforcing its natural defences.
A parallel method currently being studied is to have “resistant” vine varieties, that is to say having developed natural mechanisms to fight against these diseases (notably mildew and powdery mildew).
These grape varieties are either naturally resistant or otherwise obtained by hybridisation, an inherited technique used to select grape varieties. This technique invokes a natural fertilisation, therefore not using any genetically modified organisms.
Protection calls for either chemical mechanisms (production of a highly toxic molecule for the mildew mushroom for example) or mechanically (a variety with “scaly” skin which prevents the powdery mildew from entering the plant).
Nevertheless the risk of a resistance breakdown exists (the disease adapts to the plant which then becomes sensitive). To stave this off, French researchers are currently working of grape varieties having several resistant genes for a same disease. This multiplication of defences would allow a better long-term resistance.
The major advantage of these grape varieties is to limit the number of chemical treatments: between 2 and 3 instead of 6 or 8 (even if it’s still necessary to avoid resistance breakdowns).
Even if these grape varieties boast less quality than the traditional varieties such as Syrah, Grenache, Pinot, etc … and even if their name doesn’t mean anything from a marketing standpoint (Divico, cal 06.04, cal 32.07, …), the ongoing improvement in regards to their quality and the ecological concerns should allow them a non-negligible presence on our shelves in years to come.
For more information on Rhone wines : www.vins-rhone.com