Phylloxera is an insect that wiped out almost all the vineyards in Europe from 1863 onwards in what became known as the phylloxera crisis.
This insect, originally from America, killed all the european vines (Vitis Vinifera) by attacking the vine roots, whilst leaving the leaves unaffected. American vine varieties (Vitis berlandieri, Vitis ripària i Vitis rupestris) were attacked were affected above ground, through the leaves, but their roots were unaffected.
Thus the way to beat the plague became clear: Given that the American vitis vines did not produce quality grapes, the solution was to graft the European varieties onto American rootstock.
Since then and through to this day, this system is used throughout the world, making phylloxera a minor concern today. In the Penedès we use American rootstock like 41B, Richter 110, Pausen 1103, 161-49, etc.
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