APPLIED ECOLOGY AND ENVIRONMENTAL RESEARCH, vol.16, no.1, pp.749-759, 2018 (SCI-Expanded)
Fruit flesh softening is generally accompanied by changes in pectin structure in most fruits. In cell wall, pectin polysaccharides cross-linked with Ca2+. Especially Calcium chloride application is environmentally friendly and is also very effective on fruit quality. An experiment was performed by foliar spraying of calcium, magnesium and manganese alone and in combination to assess their effects on fruit quality, storage life and the polygalacturonic acid (pectin) content in peach (Prunus persica cv. JH. Hale). Experiment was conducted in commercial peach orchard located in Canakkale, Turkey. Treatments included 1.5% CaCl2, 2% MgSO4, 1% MnSO4, combination (0.6% CaCl2, 1% MgSO4 + 0.1% MnSO4), and control (water) applications. Spray applications were started 30 days after the full bloom, and continued at four-week intervals up to four weeks before the harvest. The amount of pectin in the peach fruits was determined by FT-IR spectroscopy. Fruit weight loss, firmness, color, titratable acidity, pH and soluble solids contents were determined. Foliar nutrient-treated trees showed improved resistance to compression and penetration, as well as a decrease in weight-loss during postharvest storage. A similar response was obtained from Mg treatments. The smallest weight loss occurred in calcium and manganese applications, which were 0.71 and 0.75%, respectively. Calcium and magnesium treatments had a positive effect on fruit flesh firmness. The highest polygalacturonic acid content was obtained with CaCl2 treatment, which was 414% greater than that of control treatment. Therefore, CaCl2 application can be safely used to increase pectin content as well as fruit quality of peach fruit.