Criteria for infection of apples by Colletotrichum acutatum causing summer rots

摘要

Cummer rot of apples is a generic term that includes several different symptoms, such as core rots, mouldy core, wound rots and surface rots, all caused by fungi. Effective control of core rots and mouldy core can be achieved by two applications ofcarbendazim at mid flowering and petal fall (Burmeister et al. 1997, unpublished HortResearch Report). Wound rots can be controlled by careful treatment of fruit to minimise wounds. The surface rots, which can also be called bitter rot, have in the past been caused by the fungus Glomerlla cingulata, also known by its imperfect name, Colletotrichum gloeosporioides. However, over the last three decades there has been a change in the causal organism to Colletotrichum acutatum and less commonly, Botryosphaeria dothidea, probably because of changes in fungicide use.