Effect of Preharvest Calcium Treatments on Sweet Cherry Fruit Quality

In this study, the effects of different foliar calcium compounds on fruit cracking and quality of sweet cherry variety '0900 Ziraat' were investigated. Calcium caseinate, calcium chloride, calcium hydroxide and calcium nitrate were used as foliar sprays. Calcium applications reduced the cracking index 38% to 66% compared to cherries that did not receive foliar treatment. The most efficient applications for decreasing cracking were calcium hydroxide and calcium chloride. Calcium chloride and calcium hydroxide were determined to be the most effective compounds, reducing cracking by 62% and 66%, respectively. Calcium caseinate also decreased fruit cracking, by nearly 50% compared to the control. However, the leaves and fruit were covered with white film. This white film can be easily removed, as postharvest processing of cherries uses water, and normally no residue remains. Preharvest foliar calcium treatments significantly decreased fruit cracking, but cracking may not be completely eliminated. None of the calcium compounds affected removal force, average fruit weight, total soluble solids, or titratable acidy. Another potentially important finding was that foliar treatment with calcium chloride significantly increased firmness of sweet cherry fruit. Calcium chloride application increased the firmness of cherries by an average of 12% compared to other compounds.