eCite Digital Repository

Uptake and internal allocation of nitrogen in apple trees


Swarts, N and Close, D and Morris, M, Uptake and internal allocation of nitrogen in apple trees, VIII ISHS Symposium on Mineral Nutrition of Fruit Crops, 27-30 June 2017, Bolzano, Italy (2017) [Conference Extract]

Pending copyright assessment - Request a copy


Objective: Improved nitrogen (N) uptake efficiency (NUE) can lead to better economic and environmental outcomes. The physiological processes of N storage and remobilisation within deciduous fruit trees are relatively well understood. However, much can be gained through better understanding of management and environmental factors on these processes. This study aimed to determine the influence of pre- and post-harvest N application on the; NUE and quantity of N allocated to storage and; the partitioning of N within the tree.

Methods: Fifteen-year-old potted 'Jonagold' trees, grafted on M26 rootstock were allocated to either pre- or post-harvest 5% N15 enriched calcium nitrate application. Pre-harvest N application trees were allocated to either summer or dormant destructive sampling. An additional set of trees was allocated to monthly sampling of leaf N15 content throughout the season. N15recovery from samples was determined using Mass Spectroscopy.

Results: No significant difference in NUE or proportion of N allocated to storage was found between trees receiving pre- and post-harvest N15 application. Determining potential losses found the efficiency of N15 resorption from leaf material was close to 100%. Timing of N application significantly influenced N distribution throughout the 'tree. Trees receiving post-harvest N application contained a significantly greater proportion of N15in the below ground organs in comparison with pre-harvest application, 52% and 23% respectively. However, trees receiving pre-harvest N15 distributed significantly more to the canopy than trees receiving post-harvest application, 52% and 26%, respectively.

Conclusion: N distribution was found to vary significantly between summer active growth and dormancy, with the N15 content of the trunk increasing from 13 to 35% and below ground N15 content increasing from 25 to 36%. Results from this study improve the current understanding of the influence of timing of N application on allocation and storage within deciduous fruit trees.

Item Details

Item Type:Conference Extract
Keywords:apple, nitrogen, 15N, tracer, use efficiency
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Horticultural production
Research Field:Horticultural crop growth and development
Objective Division:Plant Production and Plant Primary Products
Objective Group:Horticultural crops
Objective Field:Pome fruit, pip fruit
UTAS Author:Swarts, N (Dr Nigel Swarts)
UTAS Author:Close, D (Professor Dugald Close)
UTAS Author:Morris, M (Mr Matthew Morris)
ID Code:118501
Year Published:2017
Deposited By:Tasmanian Institute of Agriculture
Deposited On:2017-07-13
Last Modified:2017-07-13
Downloads:1 View Download Statistics

Repository Staff Only: item control page