Effects of summer pruning applications on grape yield and quality of the red globe grape variety

This study was carried out on 9-year old Red Globe table grape cultivar grown in Keçiborlu district of Isparta during vegetation period of 2017. Effects of summer pruning on yield and quality of 'Red Globe' grape cultivar were investigated. The shoot tipping (U) was carried out 10 days before anthesis. The leaf removal application was carried out in three different phenological stages and their combinations (U + Y1, U + Y2, U + Y3) were conducted. Leaf removal was carried out in pea size (Y1), onset of verasion (Y2) and 10 days after verasion (Y3). Summer pruning applications significantly affected cluster weight, must amount, pH, total soluble solid, titration acidity, maturity index, anthocyanin, total phenolic and L- ascorbic acid values whereas it did not significantly affect yield, fruit weight, fruit width and length, bunch width and length, total flavanol, color values (L, a, b). Among the grape quality criteria, pH (3.7) and TAA (16.4) had the highest value at shoot tipping, whereas cluster weight (1186.4 g) and titration acidity (7.17) had the highest value at U + Y2 and U + Y3 treatment, respectively. Maturity index (29.14) and must (728.3) had the highest value at Y2 and U + Y1 treatment, respectively. Among the antioxidant compounds, total phenolic content (76.96 mg GAE/ g TA acid) was highest at U + Y3 and the amount of anthocyanin (393.2 mg / l) was highest at Y2, while L-ascorbic acid (26.96 mg / 100g TA) was highest at Y1 application.