This educational system (also called U or V education) was developed in the early 1980s by Dr. Alain Carbonneau at the INRA in Bordeaux. It consists of a V- or U-shaped support structure that opens upwards and is similar to the Greek musical instrument that gave it its name. The vine trunks are about 80 cm high, the distance between the rows is at least three meters. The shoots are divided in such a way that two foliage walls with a hollow area in the middle are created (opposite to trellis training with only one foliage wall). This results in a doubling of the leaf surface and thus better utilization of solar energy or photosynthesis. The grape harvest is also favoured. Disadvantages are the increased effort for leaf care and the poor suitability for mechanical pruning.
It is a variety of Geneva Double Curtain, in contrast to the shoots which are upwardly directed. In the USA, there are different varieties such as the "Asymmetrical Lyra", in which the two leaf walls are arranged at different heights. The Tatura Trellis system developed in Australia is very similar. See also Constellations under Educational Form (Systems) and Vineyard Care (Activities).