Articles
DOES ZINC NUTRITION AFFECT CALCIUM DISORDER OF FRUITS?
Article number
564_15
Pages
135 – 143
Language
English
Abstract
A previous study has shown that foliar application of Zn in the year preceding harvesting of fruit can increase the Ca content of apple fruits and thus reduce the incidence of bitter pit.
The following working hypothesis has been advanced as a possible physiological basis to account for this observation: Supplying Zn to the plant should improve Zn nutritional status and thereby enhance IAA biosynthesis and increase IAA concentrations in shoot apices as well as in small fruits.
As a consequence of these enhanced IAA concentrations, IAA/Ca counter-transport should be stimulated and the influx of Ca into small fruits thus raised with a consequent lowering of the incidence of the Ca disorder in the fruits.
The aim of the work presented here was to examine this hypothesis using the tomato plant grown in nutrient solution culture as a model.
Tomato was chosen because it is subject to a similar Ca related disorder (blossom-end rot) as apple but is easier and faster to cultivate under controlled conditions in a greenhouse.
Tomato plants (Lycopersicon esculentum, L. cv.
Mutant 5, 1994) were grown in solution culture for a four-month period with the concentration of Zn in the nutrient medium covering the range from deficiency to optimal supply.
Leaves and fruits harvested at different but defined stages of growth were analysed for Zn and Ca concentrations and contents.
Increasing Zn supply improved the Zn content of the tomato fruits without any effect on the Ca content.
Thus, in contrast to the report on apple, the results presented do not support the hypothesis that increased Zn nutrition improves Ca inflow into young tomato fruits.
The following working hypothesis has been advanced as a possible physiological basis to account for this observation: Supplying Zn to the plant should improve Zn nutritional status and thereby enhance IAA biosynthesis and increase IAA concentrations in shoot apices as well as in small fruits.
As a consequence of these enhanced IAA concentrations, IAA/Ca counter-transport should be stimulated and the influx of Ca into small fruits thus raised with a consequent lowering of the incidence of the Ca disorder in the fruits.
The aim of the work presented here was to examine this hypothesis using the tomato plant grown in nutrient solution culture as a model.
Tomato was chosen because it is subject to a similar Ca related disorder (blossom-end rot) as apple but is easier and faster to cultivate under controlled conditions in a greenhouse.
Tomato plants (Lycopersicon esculentum, L. cv.
Mutant 5, 1994) were grown in solution culture for a four-month period with the concentration of Zn in the nutrient medium covering the range from deficiency to optimal supply.
Leaves and fruits harvested at different but defined stages of growth were analysed for Zn and Ca concentrations and contents.
Increasing Zn supply improved the Zn content of the tomato fruits without any effect on the Ca content.
Thus, in contrast to the report on apple, the results presented do not support the hypothesis that increased Zn nutrition improves Ca inflow into young tomato fruits.
Authors
Y.S. Rahayu, V. Römheld, F. Bangerth
Keywords
Ca disorders, Zn nutrition, IAA/Ca counter-transport
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