Articles
Canopy light irradiance, crop load and fruit quality in mature narrow-row planar cordon apricot canopies
Article number
1450_5
Pages
35 – 44
Language
English
Abstract
New Zealand apricot growers face increasing production costs and labour shortages.
A new growing system, planar cordons (PC), has been developed with potential to increase productivity, labour use efficiency and automation amenability.
We hypothesised that light interception at orchard scale is increased by reducing row width, whilst adequate within-canopy light irradiance is achieved by developing two-dimensional canopies.
This trial aimed to evaluate light transmission, fruit yield and quality within different canopy positions in this system and compare with adjacent centre leader (CL) trees.
Row spacings were 1.5 (PC1.5) or 2 (PC2) m for PC trees and 3.5 m for CL trees.
Bi-cordon apricot trees of ‘Nzsummer3’ and ‘Nzsummer92’ on ‘Golden Queen’ rootstocks were planted in 2015 and six upright fruiting stems developed on each cordon.
In October 2023, trees of CL, PC1.5 and PC2 were thinned to one of two crop loads.
Photosynthetic photon flux density (PPFD) was measured in different vertical positions within tree canopies over 24-h periods in January/February 2024. Tree yields and fruit quality in different positions within the trees were measured at harvest.
Light transmission to upper canopy positions was greater than lower positions in all systems, with a trend for higher light transmission to upper and mid positions in PC compared with CL trees.
Heavy crop loads resulted in greater yields in PC trees of ‘Nzsummer92’ but not other combinations.
Fruit soluble solids content was generally greater in upper canopy positions and in light crop load treatments.
In some cases, fruit were more mature in upper canopies, which may have affected results.
Narrow-row PC canopies have potential for higher yields than CL canopies, particularly for ‘Nzsummer92’, without negative effects on fruit quality, but further data and longer-term evaluations are required to confirm this.
A new growing system, planar cordons (PC), has been developed with potential to increase productivity, labour use efficiency and automation amenability.
We hypothesised that light interception at orchard scale is increased by reducing row width, whilst adequate within-canopy light irradiance is achieved by developing two-dimensional canopies.
This trial aimed to evaluate light transmission, fruit yield and quality within different canopy positions in this system and compare with adjacent centre leader (CL) trees.
Row spacings were 1.5 (PC1.5) or 2 (PC2) m for PC trees and 3.5 m for CL trees.
Bi-cordon apricot trees of ‘Nzsummer3’ and ‘Nzsummer92’ on ‘Golden Queen’ rootstocks were planted in 2015 and six upright fruiting stems developed on each cordon.
In October 2023, trees of CL, PC1.5 and PC2 were thinned to one of two crop loads.
Photosynthetic photon flux density (PPFD) was measured in different vertical positions within tree canopies over 24-h periods in January/February 2024. Tree yields and fruit quality in different positions within the trees were measured at harvest.
Light transmission to upper canopy positions was greater than lower positions in all systems, with a trend for higher light transmission to upper and mid positions in PC compared with CL trees.
Heavy crop loads resulted in greater yields in PC trees of ‘Nzsummer92’ but not other combinations.
Fruit soluble solids content was generally greater in upper canopy positions and in light crop load treatments.
In some cases, fruit were more mature in upper canopies, which may have affected results.
Narrow-row PC canopies have potential for higher yields than CL canopies, particularly for ‘Nzsummer92’, without negative effects on fruit quality, but further data and longer-term evaluations are required to confirm this.
Publication
Authors
J. Stanley, M. Schurmann, L. Keene, C. Scofield, B. van Hooijdonk, K. Breen, T. Moore
Keywords
Prunus armeniaca L., photosynthetically active radiation, 2D, two-dimensional canopies, growing systems, productivity, light interception
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