Effect of Height of Primary Scaffold Branch on Freezing Injury of Fig (Ficus carica L.)

Abstract

We investigated the effect of the height of the primary scaffold branch on freezing injury, growth, yield, and fruit quality of the fig (Ficus carica L. ‘Masui Dauphine’). The primary scaffold branch was adjusted to 1.8 m with a straight line and horizontal direction of the fruit-bearing shoots, compared with the conventional system of adjusting the primary scaffold branch to a height of 0.6 m with a straight line and vertical direction of the fruit-bearing shoots. The trees of the 1.8-m-high scaffold branch system showed less freezing injury (0% mortality) in spring over the successive two seasons, while those of the conventional 0.6-m-high primary scaffold branch system suffered 100% freezing injury. Fig growth and yield were undermined, but the fruit quality was much improved in the high (1.8 m) primary scaffold branch system relative to that of the conventional system, before freezing injury occurred. One of the reasons for the reduced freezing injury being associated with the new training system may be ascribed to the observation that the high primary scaffold branch can narrow the early morning and daytime temperature difference on the upper surface of the branch. The adoption of the 1.8-m-high scaffold branch is therefore expected to improve fig fruit quality and reduce freezing injury.