The Effects of Rootstock-Scion Relationships on Yield and Quality in Grapevine cv. Ekşi Kara (Vitis vinifera L.)

Vineyards are usually established by grafting onto vine rootstocks. Vine rootstocks affect the grafted varieties directly or by environmental factors and by changing the physiology of rootstock and scion varieties. There may be great differences in mineral nutrition of grape rootstocks and grape varieties in grafted and nongrafted combinations. The choice of grape variety and vine rootstock for vineyard ecology is vital for the sustainability of viticulture, as they affect the mineral nutrient balances, biotic and abiotic stress tolerances, yield and product quality of grape rootstocks and grafted varieties, and these change with edaphic factors. This study was carried out in ~20 years old vineyards established with vines on their own roots of Ekşi Kara grape variety (Pollinator is Gök Üzüm), which is most used in production in Konya province, and seedlings grafted onto 41B, 110R and Rupestris du Lot rootstocks. The effects of rootstock and scion nutrition were searched. Yield per vine, cluster weight, cluster number, cluster length and cluster width data showed the highest values from vines on their own roots, while the order of grafted combinations changed according to the trait measured. While the differences between °Brix and total acidity (TA) values of berry were significant (p<0.05), differences in pH and must yield were insignificant in grafted and nongrafted combinations. Nutrient contents of leaf and root samples were different compared to grafted and nongrafted combinations. Since our study area is infested with phylloxera (Daktulosphaira vitifoliae Fitch) and rootstock use is obligatory, the order of preference for grapevine rootstocks was 41 B, Rupestris du Lot and 110 R, considering yield and quality characteristics.