Innovative Precision Pruning Strategies Targeting Medium-length Fruiting Shoots to Manage Return Bloom and Enhance Shoot Quality in Apple

This study evaluates two innovative shoot-level interventions targeting medium-length shoots (MLS) in apple. Experiments were conducted on two apple cultivars, Amasya and Golden Reinders, grafted onto M.9 rootstock, to assess how heading cuts applied to flowering or vegetative MLS influence return bloom and renewal shoot quality. At flowering, tagged MLS were subjected to five treatments: untreated flowering MLS (Cont-F), untreated vegetative MLS (Cont-V), heading of flowering MLS (Head-F), heading of vegetative MLS (Head-V), and blossom thinning of flowering MLS (Thin-F). Head-F markedly suppressed return bloom in both cultivars while inducing high-quality renewal shoots, characterized by thicker shoot axes, increased spur swelling below the cut, and well-developed terminal and axillary buds indicative of improved floral bud quality. In ‘Golden Reinders’, Head-V preserved near-complete terminal flowering in the following year while enhancing renewal shoot quality.