Ethylene evolution and firmness dynamics in Mondial Gala (a, c) and Fuji (b, d) apple fruit. For Mondial Gala, the continuous lines represent the normal ethylene and softening physiology, while the dashed lines indicate the distorted ripening in 1-MCP-treated fruit (a and c). 1-MCP was not applied to Fuji fruit, thus only normal ripening is shown. Standard errors are shown by vertical lines. Points of the ethylene production curves (Mondial Gala control/Mondial Gala 1-MCP-treated/Fuji) characterized by the same letter are not significantly different (LSD test P ≤0,05). In all graphs the days of assessment are reported on the x-axes.