|Authors: ||R.B. Elkins, T.M. DeJong|
|Keywords: ||Pyrus communis, tree spacing, light interception, Tatura trellis|
A replicated trial was established in a commercial orchard to evaluate the performance of ‘Golden Russet Bosc’ (GRB) on five training systems and nine rootstocks (45 combinations of five single tree replicates). The first group of trees consisted of 2-year-old nursery- trees grafted on clonal rootstocks Old Home x Farmingdale (OHxF, Brooks series) 69, 97, 217, 333 and 513 and seedling rootstocks Pyrus betulifolia, planted in May 1993. The second group consisted of 1-year-old OHxF 40, 97 rootstocks and 2-year-old Comice/Quince BA29C interstem trees field-grafted to GRB at planting time.
Tree spacing the different systems was 1.5×5 m (797 t/ha) for the freestanding perpendicular fan and the Tatura trellis systems, and 3×5 m for the central leader, 3-leader, and parallel hedgerow systems.
Final tree height was approximately 4.5-4.7 m for the freestanding trees and 2.7 m for the Tatura trellis.
No fruit thinning was performed and delayed heading and summer pruning were performed on all systems except the parallel hedgerow which was managed with typical grower’s practice of dormant pruning only.
Of the first group, Tatura trellis and parallel hedgerow training systems had the highest accumulated gross returns (AGR) from 1999-2002, as well as significantly higher light interception and subsequently higher yields per hectare.
OHxF 69 had the highest AGR of the six rootstocks, and the combination of Tatura trellis/OHxF 69 the highest AGR of all combinations.
In 2005, there were no significant differences in gross return among training systems or combinations, however OHxF 69 and 97 grossed significantly higher among rootstocks based on yield.
The second group of rootstocks, though only one year behind the first group, failed to attain equivalent yields or returns by 2005, indicating either inherent lesser qualities than the first group of rootstocks, or persistent effects of competition.
Rootstock performance varied with training system.
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