Abstract

The effects of 3 different soil tillage treatments and 2 cluster thinning treatments on leaf water potential (Ψ_leaf), yield and quality parameters of Cabernet-Sauvignon were investigated in this study. The research was conducted (40°58'10.71 N, 27°28'21.71 E) in Tekirdag, Turkey. There were no statistically significant differences among tillage systems. Half of the clusters on a vine were removed at the veraison for cluster thinning treatments. At the result the only significant difference was on the yield, regarding the cluster thinning treatment. Yield/vine values ranged between 2.2 - 2.3 kgvine^-1 at the cluster thinning treatments and 3.4 - 3.5 kgvine^-1 at the no cluster thinning treatments. The minimum value for soluble solids in juice was 21.04% at conventional tillage, and the maximum value (21.40%) was at the conservation tillage treatments. The conventional tillage treatment showed the maximum anthocyanin level (463.78 mgkg^-1) followed by the conservation tillage treatment (460.14 mgkg^-1) and minimum tillage treatment (407.86 mgkg^-1) respectively regarding the total anthocyanin levels. The lowest phenolic compound values were obtained from CVT-NTH (361.93 mgkg^-1) treatment. On the contrary in both conservative soil tillage [CST-NTH (488.36 mgkg^-1), CST-CTH (467.79 mgkg^-1)] applications values were higher. As a result, grape quality parameters were improved by using the conversation tillage treatment with natural grassing in Cabernet Sauvignon.

Key words: Leaf water potential, water stress, soil tillage, cluster thinning, grape yield, berry composition.