Uptake and Distribution of Iron from Different Iron Sources Applied as Foliar Sprays to Chlorotic Leaves of Low-Chill Peach Cultivars

Abstract

A greenhouse experiment was carried out to examine the uptake and distribution pattern of iron applied through different iron sources to chlorotic leaves of three low-chill peach cultivars viz. Saharanpur Prabhat, Shan-e-Punjab, and Pratap. The plants were grown in sandy loam soil containing 30 g CaCO3 kg−1 soil in plastic pots. Upon the onset of iron deficiency symptoms, separate foliar spray treatments were given using Fe-sulfate [0.5 % (w/v) and 1.0 % (w/v)], Fe-citrate [0.5 % (w/v) and 1.0 % (w/v)], and Fe-EDTA [0.1 % (w/v) and 0.2 % (w/v)] in addition to the control which received foliar spray of only distilled water. All the spray solutions except distilled water were radiolabeled with 59FeCl3. Seven days after imposition of the treatments, iron uptake and distribution was monitored. Among Fe sources, the highest Fe uptake and its distribution in the leaves were recorded with Fe-sulfate followed by Fe-citrate and FeEDTA. Among the low-chill peach cultivars, the highest Fe uptake and distribution was observed with 1.0 % (w/v) Fe-sulfate in Saharanpur Prabhat followed by Shan-e-Punjab and Pratap. The least uptake and distribution of Fe was recorded with 0.1 % (w/v) FeEDTA as iron source in the cultivar Pratap. The highest increase in physiologically active iron (Fe2+) content as well as total iron content of the leaves was also observed with the application of 1.0 % (w/v) Fe-sulfate. However, the level of physiologically active (Fe2+) iron content with 1.0 % (w/v) Fe-sulfate was found to be statistically similar the application of 0.5 % (w/v) Fe-sulfate. The leaf penetration capacity of iron and subsequent distribution of iron from different iron sources in different low-chill peach cultivars were found in the following order Fe-sulfate > Fe-citrate > Fe-EDTA.