Issue link: http://winesandvines.uberflip.com/i/112023
WineEast While the yield benefits appear obvious with the GDC system, disadvantages include possible uneven ripening of fruit, sunburn (the fruit zone is at the top of the canopy and may become overexposed) and the potential to over crop if vines are not properly pruned and thinned. Occasionally, growers also will lament that clusters can become covered by excess leaf layers on the sides of the canopy, which may reduce spray penetration and increase rot susceptibility. Almost all GDC-trained vines in the East and South are hand-harvested. However, there are vineyards utilizing mechanical harvesters that have implemented this system in other areas of the country such as the San Joaquin Valley of California. Fruit hangs under catch wires with the Watson System, increasing the chance clusters will be shaded from full sun exposure. per acre. University research has been initiated to refine canopy management and crop balance on GDC-trellised vineyards in order to improve wine quality.3 Of the hybrid winegrapes tolerant of Pierce���s disease (PD), Blanc Du Bois is one of the best adapted for high-wire systems such as the GDC.4 Blanc Du Bois is a vigorous grape variety similar to Norton in that it has both modest cluster size and a procumbent growth habit. Commercial yields of Blanc Du Bois on vigorous soils in the Gulf Coast are reported in the range of 6 to 8 tons per acre on Waterloo_Nov10.qxp 8/26/10 11:36 AM Page 1 8-foot in-row vine spacing and 12-foot between-row vine spacing. The Watson System The Watson System, developed by Jerry Watson of Austin County Vineyards, has gained much popularity in the United States��� Gulf Coast region during the past five years. Initially, Austin County Vineyards was planted on 8x12 spacing on a vigorous sandy loam topsoil over clay subsoil. The original training system consisted of a high-fruiting wire at 66 inches and bi-lateral cordons. The procumbent growth of the shoots resulted in excess leaf layers in the fruit zone, causing difficulties with spray penetration and hand harvest. This problem may not be the case with high-fruiting wire systems in other parts of the country, but with the high rainfall and humidity of the Gulf Coast climate and susceptibility to rot of local hybrid grapes, the need to adapt to a more open fruit zone is imperative. Win es & Vines M A RC H 20 13 55