EFFECTS OF NITROGEN, POTASSIUM FERTILIZERS AND CLUSTERS PER VINE ON YIELD AND ANTHOCYANIN CONTENT IN CABERNET SAUVIGNON GRAPE

Abstract

The experiment was carried out in a humid subtropical climate located in the south of China, in Xichang, Sichuan province, (27oN, 102oE, and 1650 m above mean sea level) during the 2005 and 2006 seasons. Eight year old, irrigated Cabernet Sauvignon vines were planted at Xichang Chia Tai Wine & Spirits Co., Ltd. Vine plants were spaced 1.25 m apart with 2 vines and rows were 2.0 m apart and oriented approximately north/south. Vines were trained to a vertical shoot positioned training system (VSP), and were bilaterally cordon-trained, spur-pruned, and shoots were vertically positioned upright. Vines were irrigated by drip irrigation system. The 3 different levels of N-K were 0-0, 100-20, and 200-60 g/plant and the 3 different levels of clusters per vine were 10, 20, and 30 clusters per vine. Treatments were applied to 1 vine plot, each replicated 6 times in a split plot, in which the main plots were clusters per vine. Vine shoot lengths were maintained at 15 nodes by shoot trimming. It was found that the yield of grapes in year 2005 was higher than 2006. Increasing the rate of N-K in both years did not increase yields, but increased clusters increased yields in both years. Color and phenolic compounds in the berries were higher in year 2006 than 2005. At the 0-0 and 100-20 levels of N-K the phenolic compounds in the grape were lower than other treatments. It was also found that the Cabernet Sauvignon berry contained more malvidin than other anthocyanins.