By Alessio Scalisi, Darren Graetz and Shuangxi Zhou

Newly established Narrow Orchard Systems will enable researchers to answer important questions on productivity and profitability in temperate fruit crops, under current and future climates and across key Australian production regions. 

Three Narrow Orchard Systems (NOS) experimental sites have been established over Winter–Spring 2024 at the Tatura SmartFarm (Victoria), and the Loxton (South Australia) and Manjimup (Western Australia) research centres.

Apple, cherry, apricot, plum, nectarine and pear trees were planted at narrow spaces between rows and will be trained to cordon systems with 4-10 upright leaders.

Rootstock-scion interactions will be investigated across different sites.

Each site will then focus on additional site-specific research aspects.

Sites are open to visits from fruit growers and industry stakeholders to demonstrate NOS performance over the few years from planting.

Tatura

Apple, pear, nectarine, plum and cherry trees were planted between August and September 2024.

Two blocks were established:

(1) a main experimental block with the 5 different crops (~ 0.25 ha), and

(2) a demonstration block with apple only (~ 0.10 ha).

Soil preparation occurred in 2023 by surface application of 5 t/ha lime and 10 t/ha gypsum followed by cultivation and then mounding rows to provide surface drainage.

Trees will be irrigated with single driplines down each row and controlled via the existing Goldtec system at the Tatura SmartFarm.

In Block 1, trees of each crop were grafted on three different rootstocks and planted at a 2×2m (row × tree) spacing.

Trees will be trained to two different heights (2 and 3.5 m).

The interactions between canopy height and rootstock-scion combinations and their effects on productive performance will be investigated over the life of the project.

Trees will be trained to double cordons with upright leaders – using eight leaders in apples (25cm apart), six leaders in pears (33cm apart), four leaders in nectarines (50cm apart), six leaders in plums (33cm apart) and 10 leaders in cherries (20cm apart).

This orchard is covered by a Valente M system with black gabled netting over each row, supported by concrete posts.

Cherry trees will be protected by a rain cover system.

In block 2, double- and single-cordon NOS will be demonstrated.

Double-cordon trees were planted at the same spacing as in block 1 (2×2m), while single-cordon trees were planted at 1m spacing along the row, maintaining the 2m spacing between rows.

Upright leaders will be spaced at 25cm down each row.

In this block trees will be trained to a 2m canopy height. This orchard is covered by a Valente system with black hail netting covering multiple rows, as shown in Figure 1.

Loxton

A 1ha block at the Loxton Research Centre (SA) has been prepared for establishing an experimental apricot orchard (Figure 2).

Trellis construction was completed in November 2024 and followed by tree planting.

Soils are a sandy loam over limestone and have been deep ripped, cultivated and fumigated using Chloropicrin (30 g/m 2 ).

Trees are irrigated with suspended inverted full cover sprinklers placed between trees.

The experiment has been designed to test 8 replicates of 2 apricot varieties grafted to 4 rootstocks (Table 1), with irrigation infrastructure suited to applying different schedules in the future.

The principal goal of the experiment is to test the productive performance of the eight rootstock-scion combinations when planted to NOS. Trees will be planted at 2×2.5m (row × tree) spacing and trained to a bi-cordon upright fruiting offshoot (UFO) system with 10 uprights per tree (25 cm apart) to a height of 2.3 m.

The orchard will be supported by a metal post trellis (G2 netting systems, SA) hung with custom wide format wire mesh (Southern Wire, WA).

Manjimup

A 0.3ha apple orchard has been established at the Manjimup Horticultural Research Institute with 2m tree spacing and 2.5 m row spacing (Figure 3).

Trees were budded by a local nursery in February 2023 and planted in September 2024 (one year and seven months old).

Galfan-coated, corrosion-resistant trellis posts were installed.

The posts are 3m long (2.4m aboveground and 0.6m underground).

For each row, a dripline and a sprinkler line were installed to irrigate the apple trees and the interrow ground cover (a ryegrass clover mix), respectively.

In one section of the orchard, three Australian-bred apples with distinct market-oriented characteristics (the ‘ANABP 01’ Bravo/Soluna, and two selections ‘ANABP 09’ and ‘ANABP 14’) will be compared.

Trees will be trained to three configurations of NOS with vertical leaders (i.e., single cordon, double crossover cordon and standard double cordon).

In another section of the orchard, performances of the three cultivars ‘ANABP 01’, ‘ANABP 09’ and ‘ANABP 14’ on three rootstocks (the semi-dwarfing Geneva 202 and the two dwarfing M.26 and M.9 Nic 29) will be compared.

In this section, trees will be trained with standard double cordons.

The overall comparison among the three apples and the three training systems aims to investigate their timing to fill the canopy space, precocity of fruiting, and return on investment.