Effects of Rootstock and Training System on Tree Canopy, Fruit Quality and Phytochemicals of '0900 Ziraat' and 'Regina' Sweet Cherry Cultivars

Abstract

Both '0900 Ziraat' and 'Regina' grafted on 'Krymsk 5', or 'Piku 1' rootstocks were trained to either Upright Fruiting Offshoots (UFO), Super Slender Axe (SSA) or Kym Green Bush (KGB) training systems. Vegetative growth of the tree, determined by measuring trunk cross-sectional area (TCSA), canopy volume and leaf area, differed significantly, depending on the cultivar x rootstock x training system combination. In general, 'Krymsk 5' rootstock resulted in trees with significantly thicker trunks (TCSA: 37.75 cm2) and increased leaf area (up to 86.97 cm2). Fruit weight and fruit quality parameters including Hunter a*, firmness, TSS and acidity were variable between rootstocks and training systems and often not significantly different between treatments. In some years however, significant differences were highly dependent on the training system and rootstock interactions. Higher concentrations of bioactive phytochemical concentrations for total monomeric anthocyanin and antioxidant concentrations were mostly associated with the UFO training system in conjunction with the 'Krymsk 5' rootstock suggesting that these are linked to increased tree vigour and increased leaf surface area.