Expansion of the apple harvest season is most effectively obtained with selection of cultivars and strains that provide suitable quantities of fruit of the highest quality distributed throughout the harvest period. However, consumer and market demands and the physiology of the apple tree often prevent growers from attaining this goal. Three particular problems arise: the need to have fruit of a particular cultivar available for the farm stand and pick-your-own customers before and/or after the normal harvest date; the need to have more fruit of a particular cultivar available for the marketplace than can be harvested in the optimal time period; and the need to control premature, natural dropping of fruit from the trees. Previous factsheets have discussed the use of summer pruning as an approach to advance the harvest season to some degree, but substantial advancement or delay of the harvest season and control of premature drop of specific cultivars can occur only through the use of plant-growth- regulating chemicals. In this fact sheet, approaches will be divided into those which reduce or delay fruit drop and those which advance ripening a color development.