The Geneva Double Curtain System

This method was developed in the 1960's by Professor Nelson Shaulis, of Pennsylvania, who developed it while working at the Geneva Agricultural Experiment Station in New York. It is also referred to simply as GDC. The concept aims to improve grape quality by reducing shade within a dense canopy. It does this by dividing the mass of foliage into two. The trunk is grown high, about 1.5 meters. From this, two permanent cordons grow. Each cordon is trained out to run along a supporting wire, approximately 1.3 meters apart. Along the cordon are the spurs that produce the fruiting canes which hang down towards the ground. In this way, the canopy has been divided into two 'curtains', improving exposure to light. This affects the quality of fruit and the yield. It is particularly useful for vines of high vigor.