High-density navel pruning and trellis: first four seasons of results

A block of high-density ‘Attwood’ navel oranges was planted in 2004 at 3.5×4.9 m in Sunraysia, NSW, Australia.
The block has a mature tree average yield of 25 t ha^‑1 year^‑1. Typical yields of mid-season navel oranges in this region are 40-50 t ha^‑1 year^‑1. It was speculated this low yield was caused by vigorous growth resulting in a dense, over-shaded canopy that required intense annual hedging to maintain row access, which removed viable fruiting sites.
To quantify options to overcome this, two experiments were implemented in 2020 within the same block of trees: one comparing pruning treatments and one comparing trellis training systems.
The pruning experiment included mechanical hedging, hand “chunk” pruning, hand “centre limb” pruning, hand “intensive” pruning, and hand “intensive” pruning with autumn regrowth management.
Each of these treatments decreased over-shading.
Four years’ data have not shown any differences in yield between treatments.
It is possible that more time is needed for trees to adjust to the pruning regime, or the high vigour response of the trees is causing shading by mid-season.
A trellis training system experiment was established on trees adjacent to the pruning experiment in 2021. Regardless of training system, the trellised trees produced a higher crop load in 2024 than any of the pruning treatment trees.
More data are needed to conclude if trellis production is a practical and economically viable option.
A preliminary cost benefit analysis indicates an increase of at least 10 t ha^‑1 is required to account for increased capital and annual maintenance costs.

XV International Citrus Congress

S. Falivene, M. Kare, D. Monks

citrus, cordon, espalier, high density, navels, palmate, 2-D training system

https://doi.org/10.17660/ActaHortic.2026.1448.51