Articles
Seasonal pattern of sink/source limited fruit growth in ‘Improved French’ prune
Article number
1450_23
Pages
175 – 182
Language
English
Abstract
Dry fruit size determines fruit value in processed prune (Prunus domestica) production.
Crop value (average fruit size × total fruit ha‑1) in prune orchards in California, USA, is currently managed by dormant pruning and/or mechanical thinning at reference date; 35-45 days after full bloom.
Knowledge of source/sink limitations in prune fruit growth could inform thinning research seeking to improve prune crop value.
Seasonal patterns of fruit dry weight accumulation were determined (2021-23) from the same ‘Improved French’ prune trees under each of two thinning treatments: no thinning or bloom thinning.
Fruit were thinned (-6 to +18 days from full bloom) aggressively to eliminate subsequent resource limited growth of remaining fruit.
After commercial harvest and drying, fruit from bloom thinned trees weighed 30% more than those from unthinned trees, confirming source-limited growth of fruit from unthinned trees.
Significantly greater relative growth rate of fruit from bloom thinned compared to unthinned trees indicated source-limited fruit growth in unthinned trees at 1-2 weeks before reference date (2021 and 2023) and 4-5 weeks prior to commercial harvest (2023). These results suggest a potential for increased crop value if ‘Improved French’ prunes could be commercially thinned ahead of reference date under conditions of excessive fruit set.
Crop value (average fruit size × total fruit ha‑1) in prune orchards in California, USA, is currently managed by dormant pruning and/or mechanical thinning at reference date; 35-45 days after full bloom.
Knowledge of source/sink limitations in prune fruit growth could inform thinning research seeking to improve prune crop value.
Seasonal patterns of fruit dry weight accumulation were determined (2021-23) from the same ‘Improved French’ prune trees under each of two thinning treatments: no thinning or bloom thinning.
Fruit were thinned (-6 to +18 days from full bloom) aggressively to eliminate subsequent resource limited growth of remaining fruit.
After commercial harvest and drying, fruit from bloom thinned trees weighed 30% more than those from unthinned trees, confirming source-limited growth of fruit from unthinned trees.
Significantly greater relative growth rate of fruit from bloom thinned compared to unthinned trees indicated source-limited fruit growth in unthinned trees at 1-2 weeks before reference date (2021 and 2023) and 4-5 weeks prior to commercial harvest (2023). These results suggest a potential for increased crop value if ‘Improved French’ prunes could be commercially thinned ahead of reference date under conditions of excessive fruit set.
Publication
Authors
F.J.A. Niederholzer, L. Milliron, B. Wheeler-Dykes, C. Reyes, R. Rosecrance, A. Contreras, E. Smith, T.M. DeJong
Keywords
maximum fruit growth potential, Prunus domestica, sink strength, source-limited growth, fruit growth, relative growth rate, prune, plum
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