Overview of Skin Development In Normal and Russeted Apple Fruit

The developmental anatomy of the russeting process in apple fruit, regardless of its cause, is fairly predictable. Most severe russeting can be related to induction early in fruit growth, because cuticular and cell disruptions at that time will most severely inhibit expansion of the fruit surface, while fruit volumetric growth is accelerating. In this presentation, the normal development of apple skin will be reviewed and the developmental anatomy of russet will be contrasted against it. Both historical studies and the presenter’s own observations on apple russet will provide points of discussion, especially in regard to timing and severity of russet induction by fungi during fruit histogenesis.