Articles
The effect of protracted bloom on Golden Delicious fruit maturity from two climatically different areas
Article number
1346_101
Pages
791 – 798
Language
English
Abstract
It is well known that a protracted bloom period leads to mixed fruit maturities in deciduous fruit trees.
This does not just impact the timing of production practices through the growing season but also complicates harvest date projections due to high variability.
Insufficient winter chill exacerbates protracted bloom and intensifies symptoms.
To quantify the effect of flowering time (early, full bloom and late) on the maturity of Golden Delicious fruit, we followed individual fruit from the first signs of bud break until commercial harvest and post storage (12 weeks regular atmosphere) in six different orchards in each of two climatically different production areas in the Western Cape of South Africa.
Starch breakdown and flesh firmness were determined and compared over three different flowering periods (early, full bloom and late). Both climatic areas showed protracted bloom with flowering time durations of more than 4 weeks.
The flowers percentage outside the full bloom window ranged between 27 and 40% for the early period and between 25 and 27% for the late periods across the two areas.
In the region with higher winter chill, fruit from early, full bloom, and late flowers did not differ in starch conversion at harvest, but in the region with less winter chill, higher starch conversion was found in fruit from the early flowering period and lower conversion in the late flowering period.
Flesh firmness at harvest increased with increasing bloom date in both areas.
Correlations between starch breakdown and firmness levels at harvest and after storage are reported and discussed.
The results contribute to the illustration and quantification of the negative effects of protracted bloom on fruit production and suggest area-specific solutions.
This does not just impact the timing of production practices through the growing season but also complicates harvest date projections due to high variability.
Insufficient winter chill exacerbates protracted bloom and intensifies symptoms.
To quantify the effect of flowering time (early, full bloom and late) on the maturity of Golden Delicious fruit, we followed individual fruit from the first signs of bud break until commercial harvest and post storage (12 weeks regular atmosphere) in six different orchards in each of two climatically different production areas in the Western Cape of South Africa.
Starch breakdown and flesh firmness were determined and compared over three different flowering periods (early, full bloom and late). Both climatic areas showed protracted bloom with flowering time durations of more than 4 weeks.
The flowers percentage outside the full bloom window ranged between 27 and 40% for the early period and between 25 and 27% for the late periods across the two areas.
In the region with higher winter chill, fruit from early, full bloom, and late flowers did not differ in starch conversion at harvest, but in the region with less winter chill, higher starch conversion was found in fruit from the early flowering period and lower conversion in the late flowering period.
Flesh firmness at harvest increased with increasing bloom date in both areas.
Correlations between starch breakdown and firmness levels at harvest and after storage are reported and discussed.
The results contribute to the illustration and quantification of the negative effects of protracted bloom on fruit production and suggest area-specific solutions.
Publication
Authors
A.F.W. van Lingen, W.J. Steyn, E.D. Louw
Keywords
apple (Malus × domestica Borkh.), chilling units, climate change, dormancy, mild winter climate
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