Yield and canopy radiation interception of two blush pear selections in Australia

Rootstock selection is critical to maximise precocity and sustain yield of new fresh market cultivars as pear orchards in Australia transition to higher tree density and trellising systems.
Two blush pear selections (‘ANP0-131’ and ‘ANP-0534’) from the Australian National Pear Breeding program were evaluated for rootstock and interstem (‘D6’, ‘D6’ with a ‘Nijisseiki’ interstem, ‘BP1’, quince ‘MA’ and ‘MC’ with Beurre Hardy interstems) effects on canopy radiation interception (RI) and yield.
In Australia, Pyrus pyrifolia (including ‘Nijisseiki’) have high incidence of virus.
To investigate the effects of virus, independent of effects of interstem, a treatment of ‘D6’ rootstock with ‘Nijisseiki’ summer-budded to the scion was included in the study.
Trees were trained with four leaders on Open Tatura trellis at a density of 2,222 trees ha^‑1. RI each season and cumulative yield were highest for ‘ANP-0131’ (marketed as Rico^™). For each scion, use of ‘BP1’ rootstock decreased RI and cumulative yield of the first five bearing seasons (year 3 to 7 after planting). A reduction in cumulative yield was also observed for ‘ANP-0131’ trees grown on ‘D6’ rootstock with a ‘Nijisseiki’ interstem compared to trees on ‘D6’ rootstock.
Maximum yields were achieved in year 5 after planting, after which yields of approximately 60 t ha^‑1 (‘ANP-0131’) and 30-40 t ha^‑1 (‘ANP-0534’) were achieved each season.
Alternate bearing index was significantly affected by rootstock and scion.
Relationships between yield, fruit number, and fruit weight were determined for each selection, and the implications for crop load management were discussed.

XII International Symposium on Integrating Canopy, Rootstock and Environmental Physiology in Orchard Systems

L. McClymont, I. Goodwin, D.M. Whitfield

rootstock, interstem, crop load, functional yield relationships, alternate bearing

https://doi.org/10.17660/ActaHortic.2022.1346.37