Symptoms
Sunken, darkened lesions on the stem or branches that crack and exude gum, with the bark dying in patches. Girdling cankers cut off the flow of sap, causing wilting and dieback above the lesion.
Prevention
Avoid bark wounds, prune in dry weather and disinfect cutting tools between trees. Maintain tree vigour with balanced nutrition and good drainage.
Treatment
Organic
Cut out the canker back to healthy wood and seal with a copper paste. Remove and destroy prunings and keep the canopy open for airflow.
Chemical (last resort)
Paint cankers with a copper or carbendazim formulation after surgery and spray the canopy preventively in wet weather. Observe PHI on fruit trees.
Affects 1 crop
Sources
MARDI Fruit Crop Guide; DOA IPM Manual