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| Authors: | B. Bengtsson, P. Jensén |
Abstract:
Deficiency of calcium and boron in fruits of apple is a great problem which cause physiological disorders and strorage damages.
The aim was to study the effects of different nutrient supply on transport of calcium and boron in the trees and the interaction between the two elements in their transport to the fruit.
Trees of Queen cox were grown hydroponically in a climate chamber.
Calcium and nitrogen were varied in the nutrient solution.
Boron was added as enriched 10-B and calcium as 45-Ca, to analyse uptake and transport of these elements.
In another experiment with trees of 5-year-old Cox orange grown in the field, transport of boron (10-B) and calcium (45-Ca) to the fruit was registrated at various stages of fruit development.
The transport capacity in trees supplied with 10 and 40 kg N/ha year, respectively, was compared.
Transport of boron to fruits in early expansion was reduced by high supply of calcium, while a simultaneous high supply of calcium and nitrate increased both calcium and boron transport into young fruits.
Transport of boron and calcium to the fruit decreased during fruit development.
Transport to fruit compared to leaves, was much more restricted for calcium than for boron.
There appears to be a ‘barrier’ for transport of calcium to the fruit, while boron is more freely transported.
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