Abstract

The study was conducted to examine the effects of CaCl₂ postharvest treatment on development of   anthracnose, measured as lesion size and quality of red-flesh dragon fruit (Hylocereus polyrhizus). Fully matured fruits were treated with varying concentrations of Ca by soaking the fruits for 30 min in solutions containing 0, 1.0, 2.0, 3.0 and 4.0 CaCl₂gL^-1. After drying, the fruits were inoculated with spore suspensions of C. gloeosporioides(106 spores L^-1). Calcium chloride applied at varying concentrations did not produce significant effect on anthracnose incidence, but the size of lesion was linearly reduced with increasing Ca concentration. Calcium chloride application as postharvest treatment markedly elevated fruit Ca content especially in the fruit peel, but without influencing the N, P, K and Mg contents. Fruit firmness increased with Ca application while pH, soluble solids concentration and titratable acidity were not affected by the treatment. The effect of anthracnose on firmness, pH, SSC and TA of the fruits were reduced with CaCl₂treatments. 

Key words: Pitaya, postharvest quality, postharvest disease, fruit firmness, mineral nutrients.