Quantification and modelling of the stomatal, cuticular and crack components of peach fruit surface conductance
Résumé
This study describes the components of fruit surface conductance. It aims to revise a modelling framework examining water loss across the fruit epidermis in relation to time and fruit growing conditions. For this purpose, cuticular crack surface area, healing artificial wounds in vivo, stomatal number and total fruit surface conductance were quantified during nectarine (Prunus persica L. nucipersica) fruit growth under contrasted irrigation regimes or thinning intensities. The contribution of stomatal component to total conductance decreased very early. A sub-model of the specific cuticular conductance according to fruit age was proposed that accounted for the complex temporal variation of the cuticular component. The occurrence of cracks was modelled by considering the relative expansion rate of the cuticle as a function of fruit fresh mass and relative expansion rate of the fruit. Healing decreased with fruit age. The observed temporal variations of fruit surface conductance and cuticular crack surface area were well simulated by the modified model whatever the fruit growing conditions. Tests on independent data revealed that the model was highly sensitive to parameters related to cuticular crack development and to cuticular properties