THE EFFECTS OF CA APPLICATIONS ON PEACH FRUIT MINERAL CONTENT AND QUALITY

Late season peach cultivars are usually cold stored for a few weeks to extend the marketing season, but physiological disorders related to calcium deficiency are now emerging. To study the absorption of Ca by the peach fruit, mature trees of two late-maturing cultivars: ‘Miraflores’ and ‘Jesca’ were treated with Ca applied in two different ways: either as foliar sprays of Ca water solutions, or rubbed on the fruit with a Tara gum gel containing the Ca solution. In both cases, the Ca source was CaCl₂. Repeated foliar sprays along the growing season, of aqueous solutions of Ca concentrations ranging from 0.25 to 1% Ca did not affect the concentration of Ca in the peach skin or fruit flesh. Similarly, no effects on the fruit quality traits were observed at harvest. In a second experiment, fruits were rubbed with a calcium containing gel. A great increase in Ca concentration was found both on skin and flesh of fruits treated with 1% Ca. However, fruits treated with 1% Ca resulted in lower flesh firmness and were flat-shaped and exhibited an increased rate in fruit drop.