Effect of rootstock on ‘Forelle’ pear (Pyrus communis L.) growth and production
European pears (Pyrus communis L.) are predominantly planted either on pear (P. communis) or quince (Cydonia oblonga L.) rootstocks. High-density commercial pear orchards require dwarfing rootstocks and the South African selections BP1 and BP3 were considered too vigorous. The growth and production of the important export cultivar ‘Forelle’ were evaluated on a range of rootstocks at three sites for between seven and nine seasons. In the final season, the trunk cross-sectional area (TCA) of trees on Pyrodwarf (PD), ‘Old Home’ × ‘Farmingdale’ (OHxF) 217, BU2/33, BP3, OHxF40 and BP1 averaged >100.0 cm2, with the smallest trees on Quince C51 (QC51). Trees on PD, OHxF217, BP1 and OHxF40 yielded >30.0 kg tree−1, whereas trees on Quince A (QA) and QC51 yielded <25.0 kg tree−1. Trees with a yield efficiency of 0.29–0.35 kg cm−2 TCA were on OHxF97, PD, QC51, OHxF333 and OHxF217, whereas trees on BP3 had a yield efficiency of <0.21 kg cm−2 TCA. Trees on OHxF217, OHxF40 and BP1 had a cumulative yield of >100.0 kg tree−1, whereas trees on QC51 and QA had a cumulative yield of <60.0 kg tree−1. The best rootstock was OHxF217, followed by OHxF40 and OHxF97. PD and OHxF333 also performed well but were evaluated at one site only.
Keywords: cumulative yield, trunk cross-sectional area, yield, yield efficiency