New planting systems to increase apple orchard profitability in Argentina: preliminary results

Abstract

Apples and pears are the main fruit production of the north Patagonian valleys. Many training systems suitable to be mechanized (pruning, thinning, use of platforms) are used in different fruit growing areas to improve yield and precocity. As results depend on environmental conditions, local studies are needed to compare the performance of different training systems in our local conditions. The aim of the study was to compare four training systems: central axis (CA), 4 axes obtained by heading-back at plantation time (4A-C), and 2 axes (2A-B), 3 axes and multi-leaders (ML) obtained by bending trees, in ‘Washington Spur’, ‘Brookfield’ and ‘Rosy Glow’ apple trees. The plot was planted in an orchard located in Rio Negro, Argentina, in June of 2016 at 3.5 m row space, and different distances between trees according to the variety/rootstock combinations (0.5, 1.0, 1.5, and 2 m). Light interception, yield as well as fruit size, and maturity indexes were recorded on each cultivar. The efficiency of the use of labor was assessed in pruning, thinning, training, and harvest. In the 2018-19 season, the highest yield was observed in central axis at 1.0 m (2,857 trees ha‑1) in ‘Brookfield’/‘M.9’ and ‘Rosy Glow’/‘M.9’ (16.3 and 23.7 t ha‑1 respectively), and at 0.5 m (5,714 trees ha‑1) in ‘Washington Spur’/‘MI.793’ (15.7 t ha‑1). Interestingly, bending trees to obtain more than one axis reduced production only in ‘Brookfield’. As expected, heading back the trees at the time of planting delayed production in all cultivars.