Effects of different water stress levels on heterogeneity and berry composition in an organic and conventional growing of Cabernet-Sauvignon grapevine (Vitis vinifera L.) Cv.'s

The first parcel of the researched field is a certified organic vineyard of Chateau Nuzun which is located in Çeşmeli village of Tekirdağ. The coordinates of this vineyard is 41° 2' 20.74" N and 27° 48' 41.90" E. It is elevation is 130 m and it is 13 years old. In the VSP trained vineyard, the row spacing is 2.5m and spacing between vines is 2m. It has a slope of 18% and row direction is north to south. The vineyard is composed of cv Cabernet Sauvignon plants which are grafted over 1103P rootstock. The second parcel of the researched field is a a conventional vineyard of Umurbey which is located in Yazır village of Tekirdağ with coordinates of 40° 55' 38.59" N and 27° 25' 20.93" E. In this vineyard cv Cabernet Sauvignon is grafted over 5BB rootstock. Our research is performed in cv. Cabernet Sauvignon vines with different water stress levels. In both organic and conventional (K) vineyards, our trial design has 2 main parcels and 2 sub-parcels with 3 replicates. The vine plants are grouped based on, Ψşö, leaf water potential before sun-set as lower than -0,8 MPa and greater than -0,8 MPa after in filed measurements. This grape vines are classified based on soil type as being deep soil and shallow soil. There are 6 different groups composed of Control, Stress-1 and Stress-2 in shallow soil and Control, Stress-1 and Stress-2 in deep soil. The trial is performed for each group as 3 replicates for each of which there are 2 plants and for each plant we collected 4 random grape bunches. The bunches picked are first analyzed based on the bunch lenght and width then they are destemmed and sorted based on berry sized as 10mm-12mm, 12mm-14mm, 14mm-16mm. Berry size and stress levels combined together, i.e. Control (K), Stress 1 (S1 > -0,8 MPa) and Stress 2 (S2 < -0,8 MPa), determined the grouping to extract juice to analize. At the end of this trial, based on berry sizes, the values of fenol, antosiyanin, antioxidan are shown to be dependent to soil type, yield, viticulture practices as well as water availabilty at different harvest times.