An early 1960s by the US winegrower Dr. Nelson Shaulis (1913-2000) at the Cornell University (Geneva, New York State) developed an education system (double curtain education). It belongs to the large group of the so-called Spurred cordon systems, Originally it was made specifically for the grape variety Concord created a machine vintage to enable. The vines are pulled onto a high T-shaped frame (also V-shaped). The distance between the rows of vines is about three meters. The young shoots are divided to the left and right and the leaves are guided onto two foldable wire frames.
By folding down, the plant grows down, which inhibits the vigor and improves the incidence of light. The system has in the United States and Australia acquired little importance; it has not proven itself in Europe. A variant is the duplex education developed in California, which enables a largely mechanical harvest. Only the grape-bearing fruit rods (not the leaf shoots) are attached to a wire. The developed in France Lyra education is also similar, but the shoots are directed upwards. See also under training system (Systems) and Weingarten Care (Activities).