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The leaves of various species of fruit trees in 1sf ahan regions exhibit chlorosis when grown on the calcareous soil, due to the decrease of iron availability to plants or iron inactivation within the plants.
For the purpose of this study, the amount of chlorophyll and mineral elements within the leaves of chlorotic quince shoots(Cydonia oblonga Miller, a local cultivar) which were treated with iron chelate were determined. The above—mentioned parameters were also determined in the newly—developed leaves of young apple trees, in summer and autumn. These leaves were chlorotic when grown in summer but green in autumn.
The application of 50g of iron chelate sequestrene 138 Fe as a soil drench prevented chlorosis in quince trees which were irrigated every 10 or 20 days. The application of the same amount of iron chelate during the 10- day period proved to be more effective.
Regreening ability of chlorotic quince leaf after the addition of ammonium sulfate or potassium sulfate was very poor, and the leaves of these trees remained chlorotic.
When iron chlorosis was treated with iron chelate, a change in chlorophyll and mineral content within the leaves was observed, the percentage of K, Mg,Mn,within the leaves were decreased, while the concentrations of Fe and chlorophyll were increased. The decrease of the N-Content was observed only in the case of the 10-day watering interwal.
In various cultivars of young apple trees, the amounts of chlorophyll, Ca, and Fe within the newly-developed leaves grown in summer were less than those grown in the same shoots in autumn. Conversely, the mineral contents, (N, P, K) of newly—developed leaves were increased in summer, hut decreased in autumm.
Changes in mineral contents of such leaves in response to differential chlorophyll content appear to be associated with the interference in growing meristem tissues.