Natural sources of spraying to preserve apple fruit quality during post-harvest

Abstract

One of the great challenges that apple producers face is to substantially improve the quality of fruit, including after harvest. A balanced and timely supply of calcium (Ca) during growth and in the post-harvest stage is considered a technique that could improve shelf life and fruit quality; thus calcium plays a key role during post-harvest, with calcium carbonate and calcium sulphate being an alternative of foliar spraying. The study was carried out on 'Top Red' and 'Golden Delicious' apple cultivars, in a randomized complete block design with 13 treatments (referring to different commercial presentations of calcium) and 6 repetitions; 8 foliar sprays were applied weekly, from June 22 until harvest; 'Top Red' (151 days after full flowering, DDCF) and 'Golden Delicious' (145 DDCF) fruit were evaluated in regard with fruit traits (diameter, weight and colour) and maturity (pulp firmness, total soluble solids, titratable acidity and sugar acidity ratio). In 'Top Red' cv., calcium carbonate presented the best results, with intermediate to high quality apple fruit, while for cv. 'Golden Delicious' the best results were obtained with calcium sulphate, which increased fruits' diameter, weight, colour and titratable acidity. Even more, of the products evaluated, CaCO3 and CaSO4 had the lowest costs, and can be considered as good alternatives of foliar calcium supplement applied in order to preserve the quality of the apple during post-harvest.