Topics:

• Key research findings
• Experimental design
• Time series videos

Key research findings

Training systems

Yield tended to be highest in the ‘High’ and ‘Ultra-High’ density Open Tatura trellis (on D6 and QA rootstocks) attributed to fruit size. More intensive tree management may be required to ensure adequate colour development in Open Tatura systems.

Planting Densities

Growers seeking to maximize yield should consider high density (~ 2200 trees/ha) plantings on D6, or Quince A rootstocks (with Beurre Hardy interstems). There was no yield benefit from increasing tree density from ‘High’ to ‘Ultra-High’ (~4400 trees/ha), consistent with predictions from economic modelling.

For growers wishing to remain with moderate planting densities (~1100 – 1400 trees/ha), D6 is so far the most attractive rootstock option with moderate crop loads and good fruit size resulting in maximum total yields and pack-out as trees approach maturity. By contrast, in low density planting systems (~700 – 1100 trees/ha), crop load and fruit size of trees on QA rootstocks in fifth-leaf was sufficient to maximize total yield and pack-out yield while avoiding oversizing of fruit.

Pictures of high density plantings on rootstock D6, and Quince A with Beurre Hardy interstems.

Experimental design

In the planting systems experiment, an extensive range of training systems and tree densities for 3 rootstocks are being compared.

Trees are grafted to rootstocks D6, BP1 and Quince A (with Beurre Hardy interstem) and planted at densities ranging from 741 to 4444 trees per ha. The trees are trained as multi-leader trees (2, 4, 6 or 8 leaders) on Open Tatura trellis, single or multi-leader trees (2, 4 or 6 leaders) in vertical hedgerows, freestanding central leader systems or as a vase (the control treatment).

Table 1. tree training and tee density treatments in the Planting Systems experiment. Each of these has the 3 rootstocks.

Tatura trellis systems are commonly reported to produce high yields due to increased light interception. However, yields are not always significantly improved compared to alternative systems. For example, 'Golden Russet Bosc' pears planted at low density (797 trees/ha) in parallel hedgerows (palmette) produced similar yields to those planted at medium density (1594 trees/ha) on Tatura trellis during the first decade of orchard life (Elkins et al. 2008). Similarly, comparisons of training systems have reported higher early yields from multi-leader systems compared to single leader trees in some, but not all, experiments (Musacchi 2008, Elkins et al. 2008). Costs of establishing and managing (including time spent training and pruning trees) each system in the Planting System experiment will be recorded.

Comparing plantings systems

A look at Blush Pear ANP-0131 on Open Tatura, Vertical and Traditional planting systems

See table 1 and table 2 for more detail.

Photos taken April 2019

Open Tatura trellis planting systems

Vertical trellis planting systems

Traditional planting systems

Videos on Pruning and Training

Time series videos

Every few weeks photos were taken of each experiment, and produced into a video to show the resulting growth of tree canopies and fruit development.

Time series videos trials A to L

Table 2: Profitable Pears Orchard - Planting systems experiment (list of trials A to L)

^{This project, AP12002 Profitable Pears: Maximising productivity and quality of new pear varieties, is funded by Agriculture Victoria with co-investment from Horticulture Innovation Australia Limited using the apple and pear levy and funds from the Australian Government}