Fruiting branch development in apple

The fruiting habit of apple trees is influenced by its architecture, or the location of shoots along the branch. In areas of insufficient chilling architecture is modified due to differential growth potential of buds along the shoot. In this trial, 2-year-old shoots from three cultivars (Red Delicious, Golden Delicious, and Granny Smith) were selected in both an area with insufficient chilling and one with expected sufficient chilling. Additionally, the 1-year-old shoot adjoining shoot section was either left intact or pruned in the July preceding budbreak in order to characterize the influence of apical dominance on budbreak according to cultivar and area. Time of budbreak was monitored according to position within the shoot and resulting sizes and types of the laterals were measured. Area (sufficient or insufficient chilling) influenced the position and density of fruit within the 2-year-old shoot. Removal of the 1-year-old shoot section resulted in earlier budbreak regardless of area or cultivar, and produced a small burst of vegetative growth early in the spring.  Time of budbreak differed according to cultivar.  Cultivars had a similar budbreak pattern within a location, regardless of whether the 1-year-old shoot was removed or left intact, but this cultivar effect differed between areas.