Key research findings

Quince A rootstocks with Beurre Hardy interstem (QA/BH) produce fruit earlier and set fruit well but the high crop loads increase the likelihood of needing thinning intervention to ensure adequate fruit size. Conversely, in years with low fruit set, trees with D6 rootstock may lose pack-out yield due to oversizing of fruit. At this stage, D6 can be recommended as a preferred rootstock for use with ‘ANP-0131’ due to high pack-out yields (yield of fruit 150 – 280 g) of fifth-leaf trees. QA/BH and QC/BH (Quince C rootstocks with Beurre Hardy interstem) are preferred rootstocks for ‘ANP-0118’ on the basis of yields of young trees. However, crop load management appears necessary to size fruit with these rootstocks and long-term production may be improved by use of D6. ‘ANP-0534’ performed similarly well on QA/BH, QC/BH and D6 rootstocks. Use of BP1 rootstock is not recommended with any of the cultivars due to lower yield potential.

To date, assessments of rootstock performance have focused on total annual and cumulative yield in the first three years of production. Ultimately, cultivar x rootstock combinations that set moderate crop loads with minimal interventions once trees reach full production may be more profitable than trees with a tendency to crop heavily and undersize fruit. Further investigations of long-term trends in flower density and fruit set, and desirable crop loads for each cultivar x rootstock are required to ensure maximum pack-out.

Experimental design

In the Rootstock experiment, all three blush pears (ANP-0118, ANP-0131 & ANP-0534) have been planted on rootstocks D6, D6 with a Nijisseiki interstem, BP1, BM2000, and Quince A and Quince C with Beurre Hardy interstems, and trained to a four leader, Open Tatura trellis system.  The primary aim of this experiment is to determine which rootstocks are most appropriate for use with each cultivar, based on tree growth, precocity and yield. A secondary aim is to examine the effects of pome fruit viruses on productivity of pears.

Rootstock Experiment in Pear Field Laboratory with Dr Ian Goodwin

Dr Ian Goodwin introduces a Rootstock experiment for the Profitable Pears project in the Pear Field Laboratory, based at Tatura, Victoria

Previous testing has revealed the presence of apple stem grooving virus in some Asian pear material in Australia, including the Nijisseiki material to be used in this project. This virus is considered undesirable in apple trees and is associated with reduced yields. However, it has been suggested that impacts are less severe in pears and that the presence of such viruses may help control vegetative vigour. A comparison of the D6 treatment with the D6-Nijisseiki treatment is insufficient to determine the effects of virus as the presence of an interstem can impact tree attributes. Consequently, a seventh treatment, where trees on D6 rootstock are virus infected by temporary budding of Nijisseiki material, will be imposed.  This will enable the effects and interactions of interstem and virus to be untangled.

Summary results - Rootstock for blush pears

Summary of the effects of currently available rootstocks on growth, yield and quality of new red-blushed pear cultivars.

Key messages:

  • Third leaf flower cluster number, fruit number and yield of cultivars ANP-0118 and ANP-0131 were highest when grafted to Quince A and to a lesser extent, Quince C rootstocks.
  • Leader height at the end of the third leaf for cultivars ANP-0131 and ANP-0534 tended to be less when grafted to BP1, Quince A and Quince C rootstocks.
  • There was no effect of rootstocks on fruit colour, firmness, sweetness and maturity for each of the cultivars.
Time Series Videos: Rootstock experiments 2015 – 2017

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 M - Z, AC - AI

Table 1: Profitable Pears Orchard - Rootstock experiments (list of trials M - Z, AC - AI)

/ Cultivar
MOpen Tatura4 Leader1 mD6 x ANP-0118 (LanyaTM)
NOpen Tatura4 Leader1 mBP1 x ANP-0534
OOpen Tatura4 Leader1 mD6 x ANP-0534
POpen Tatura4 Leader1 mD6 x ANP-0118 (LanyaTM) + Virus
QOpen Tatura4 Leader1 mD6 x ANP-0131 (DelizaTM)
ROpen Tatura4 Leader1 mD6/Nij x ANP-0118 (LanyaTM)
SOpen Tatura4 Leader1 mQA/BH x ANP-0534
TOpen Tatura4 Leader1 mBM2000 x ANP-0118 (LanyaTM)
UOpen Tatura4 Leader1 mQC/BH x ANP-0118 (LanyaTM)
VOpen Tatura4 Leader1 mBM2000 x ANP-0534
WOpen Tatura4 Leader1 mD6 x ANP-0534 + Virus
XOpen Tatura4 Leader1 mBM2000 x ANP-0131 (DelizaTM)
YOpen Tatura4 Leader1 mBP1 x ANP-0118 (LanyaTM)
ZOpen Tatura4 Leader1 mD6 x ANP-0131 (DelizaTM) + virus
ACOpen Tatura4 Leader1 mQC/BH x ANP-0131 (DelizaTM)
ADOpen Tatura4 Leader1 mQA/BH x ANP-0118 (LanyaTM)
AEOpen Tatura4 Leader1 mQC/BH x ANP-0534
AFOpen Tatura4 Leader1 mQA/BH x ANP-0131 (DelizaTM)
AGOpen Tatura4 Leader1 mD6/Nij x ANP-0534
AHOpen Tatura4 Leader1 mBP1 x ANP-0131 (DelizaTM)
AIOpen Tatura4 Leader1 mD6/Nij x ANP-0131 (DelizaTM)

QA = Quince A

QC= Quince C

BH = Beurre Hardy interstem

Nij = Nijisseiki interstem

Virus = apple stem grooving virus

Virtual Orchard Tour - A look at tree structures in the rootstock experiments

360 degree photos of tree structures in the Blush par research orchard

Warning: this software uses a lot of data and may take time to load each panoramic (360 degree) view of the orchard.

*Tour software works best in Chrome or Internet Explorer 11

How to navigate: DESKTOP Computer

To move the picture for a 360 degree view: Use mouse + hold left button

To zoom in and out: use scroll wheel on mouse

To move to the next picture: Select panos (round circle on screen)

Select menu in top right corner for more options.

  • Full screen
  • Auto rotation on/off
  • Auto follow on/off

This project, AP12002 Profitable Pears: Maximising productivity and quality of new pear varieties, is funded by the Department of Economic Development, Jobs, Transport and Resources with co-investment from Horticulture Innovation Australia Limited using the apple and pear levy and funds from the Australian Government