S13 - Session P2 - Mineral nutrition and internal defects in vapour heat treated mango

Authors: Muhammad Asad Ullah *, Daryl C. Joyce, Amit Khanal, Andrew J. Macnish, Neil A. White, Priya A. Joyce, Richard I. Webb

Optimum fruit quality is crucial for export lines. For Calypso TM mango fruit, Vapour Heat Treatment (VHT) is an important post-harvest measure for fruit fly control. However, this phytosanitary treatment has been associated with the expression of physiological disorders in mango fruit. Among other determinants such as fruit maturity, robustness at harvest and postharvest quality through supply chains are linked to preharvest mineral nutrition. Notably, fruit nitrogen (N) to calcium (Ca) balance is broadly related to fruit robustness and innate capacity to tolerate postharvest stresses. A multi-year N and Ca field trial was established in a commercial orchard. Calypso TM fruit at commercial maturity (Avg. 14.43 % dry matter) were subjected to VHT vs. no VHT treatment. During shelf-life assessment at 20 o C, VHT treated fruit exhibited shorter shelf-life (15.3 d) than non-VHT control fruit (20.6 d). Three distinctly different internal disorders were observed in afflicted fruit at eating ripe. These were Flesh Cavity (FC), Flesh Cavity with White Patches (FCWP) and Ricyness (R). FC was evident in both VHT and non-VHT fruit. Incidence and severity of FC were evidently associated with fruit size by weight at harvest. FCWP and R appeared only in VHT fruit. FCWP severity was evidently associated with mesocarp N:Ca ratio. Enriched data sets could inform predictive modelling for incidence and severity of FCWP in Calypso TM mango subject to VHT.