Effects of Girdling on Freezing Injury of Fig (Ficus carica L.)

Abstract

We examined the influence of girdling on freezing injury of ‘Masui Dauphine’ fig (Ficus carica L.). Freezing injury was observed in cuttings planted in the field at the bud breaking stage. Injury was alleviated in the cuttings with girdling during the previous autumn due to delayed bud breaking. In addition, when the girdling-treated scion was separated into three portions: top, intermediate and basal (according to the growing order) with each having 2–3 buds, the cuttings in the basal portion were less susceptible to freezing injury than cuttings from the top and intermediate portions. The buds in the potted-cuttings could not survive at less than −3°C after low temperature treatment at the bud breaking stage. However, buds from the potted-cuttings with girdling during the previous autumn recorded less freezing injury and showed increased sugar and starch contents. There was also delayed bud breaking in potted-cuttings with girdling. Higher sugar and starch contents and less freezing injury during the cold season were observed in the scion from field-grown young fig trees with girdling during the previous autumn compared to that without girdling. Thus, it is suggested that girdling can ameliorate freezing injury both during the cold season and at the bud breaking stage by enhancing the reserve nutrients in dormant branches and delaying the date of bud breaking.