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.
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.
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.
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
360 degree photos of tree structures in the Blush pear research orchard.
|M||Open Tatura||4 Leader||1 m||D6 x ANP-0118 (LanyaTM)|
|N||Open Tatura||4 Leader||1 m||BP1 x ANP-0534|
|O||Open Tatura||4 Leader||1 m||D6 x ANP-0534|
|P||Open Tatura||4 Leader||1 m||D6 x ANP-0118 (LanyaTM) + Virus|
|Q||Open Tatura||4 Leader||1 m||D6 x ANP-0131 (Ricō®)|
|R||Open Tatura||4 Leader||1 m||D6/Nij x ANP-0118 (LanyaTM)|
|S||Open Tatura||4 Leader||1 m||QA/BH x ANP-0534|
|T||Open Tatura||4 Leader||1 m||BM2000 x ANP-0118 (LanyaTM)|
|U||Open Tatura||4 Leader||1 m||QC/BH x ANP-0118 (LanyaTM)|
|V||Open Tatura||4 Leader||1 m||BM2000 x ANP-0534|
|W||Open Tatura||4 Leader||1 m||D6 x ANP-0534 + Virus|
|X||Open Tatura||4 Leader||1 m||BM2000 x ANP-0131 (Ricō®)|
|Y||Open Tatura||4 Leader||1 m||BP1 x ANP-0118 (LanyaTM)|
|Z||Open Tatura||4 Leader||1 m||D6 x ANP-0131 (Ricō®) + virus|
|AC||Open Tatura||4 Leader||1 m||QC/BH x ANP-0131 (Ricō®)|
|AD||Open Tatura||4 Leader||1 m||QA/BH x ANP-0118 (LanyaTM)|
|AE||Open Tatura||4 Leader||1 m||QC/BH x ANP-0534|
|AF||Open Tatura||4 Leader||1 m||QA/BH x ANP-0131 (Ricō®)|
|AG||Open Tatura||4 Leader||1 m||D6/Nij x ANP-0534|
|AH||Open Tatura||4 Leader||1 m||BP1 x ANP-0131 (Ricō®)|
|AI||Open Tatura||4 Leader||1 m||D6/Nij x ANP-0131 (Ricō®)|
QA = Quince A
QC= Quince C
BH = Beurre Hardy interstem
Nij = Nijisseiki interstem
Virus = apple stem grooving virus
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