Effects of Limb Retention on Apple Trees Pruned to Tall-spindle Shape on Fruit Yield and Quality

  Objective  The optimum amount of limbs to be retained on an apple tree pruned to a tall-spindle shape that would result in high-yield of quality fruits was investigated.

  Method  Effects of the amount of saved limbs after pruning on fruit yield and quality of 5–7 years old dwarf apple trees were determined.

  Result  The average fruit yield per apply plant increased, and then declined, with increasing number of limbs retained, within a range, after the pruning. The yield peaked when 25 main branches were saved, while the individual fruit weight maximized when 23–24 limbs remained on a plant. The greatest total soluble solids (TSS) and anthocyanin contents in the apples were found on the trees with 23–25 limbs retained and decreased as the number of the limbs increased. The correlations between the limb retention and those indicators were significant with coefficients ranging between −0.721 and −0.964.

  Conclusion  Taking the yield per plant as well as the individual fruit weight, TSS, and total anthocyanin of apples into consideration, a 5–7 years old dwarf tree could be pruned onto a tall-spindle shape with 24.29 limbs remaining to achieve maximized results.