Seasonal Development of the Leaf Canopy of ‘Macspur McIntosh’ Apple Trees

Leaf canopy development of 7- and 10-year-old- ‘Macspur McIntosh’/M.7 apple ( Malus domestica Borkh) trees was studied in 1986. All growing points were counted on six trees of each age at budbreak and at appropriate intervals thereafter. The growing points were divided into old spurs, new spurs, terminal shoots, lateral shoots, and bourse shoots. Only old spur leaves were present from budbreak to pink; at pink, terminal shoots could be distinguished; at petal fall, the other three types could be identified. Shoot leaves averaged nearly 50% larger than spur leaves and made up 36.8% of the leaf numbers and 45.7% of the leaf area at full leaf. The leaf canopy was 10% complete at full bloom and 23% complete at petal fall. Total leaf area/tree increased 8-fold in the 4 weeks after full bloom.