Effect of temperature on mycelial growth of Alternaria alternata and Colletotrichum gloeosporioides isolated from papaya fruit

The objective of this study was to evaluate the influence of temperature on mycelial appearance time (t_v) for Alternaria alternata and Colletotrichum gloeosporioides isolated from papaya rots by predictive mathematical models and to evaluate their performance in predicting fungal growth. The Baranyi and Roberts models were used to estimate the radial growth rates (µ). The cardinal model with inflexion was applied to model µ as a function of the temperature for A. alternate. A polynomial function was used to model t_v for A. alternata, whereas the Arrhenius-Davey model for C. gloeosporioides. Simulations of t_v were conducted with data obtained on the papaya fruit. The resulted models seem satisfactory to describe t_v. The model provides insight into the dynamics of postharvest fungal disease and forms the basis of a predictive model to be used by transporters to determine how long a fruit can be conserved before the infection starts. Highlights The main postharvest rots of papaya are C. gloeosporioides and A. alternata. The time of mycelium appearance may be useful to determine the shell life. Correlations exist between fungal growth in vitro and in the real matrix. The results may help us to improve the supply chain.