Die-back & branch canker
Shoots and branches drying back from the tip inward, often with sunken cankers on the wood — worst on stressed, wounded or neglected trees.
- Pathogen
- Wound/stress fungi (Colletotrichum, Botryosphaeria)
- Spreads by
- Air/rain-splashed spores; through wounds
- Favoured by
- Stressed/wounded/neglected trees
- Main risk
- Shoots & branches die back; canopy thins
Overview
Die-back is the progressive drying and death of shoots and branches from the tip backward toward the trunk, seen in mango, citrus, pomegranate and many other trees. It is caused by a group of wound- and stress-associated fungi (such as Colletotrichum, Botryosphaeria/Lasiodiplodia and others) that enter through pruning cuts, dead tips, sunburn, insect and mechanical wounds, and then advance down the shoot, killing the bark and wood. The affected twig browns, the leaves dry and hang on, and the die-back moves steadily inward.
On larger branches the same fungi can form sunken, discoloured cankers on the bark, sometimes with gum, that girdle and kill the branch beyond them. Die-back and canker are far worse on trees that are stressed, water-stressed, nutrient-deficient, insect-damaged or neglected, and after heavy or careless pruning. Because the fungi are wound- and stress-driven, management centres on keeping trees vigorous, pruning affected wood well back into healthy tissue, protecting the cuts, and good orchard sanitation.
How to identify it
- Shoots and branches drying and dying from the tip backward, with browned twigs and dried leaves that hang on.
- Die-back advancing steadily inward toward larger branches and the trunk.
- Sunken, discoloured cankers on the bark of larger branches, sometimes oozing gum, girdling the branch.
- Worst on stressed, water- or nutrient-stressed, insect-damaged or neglected trees, and after heavy pruning.
What causes it and when
- A group of wound- and stress-associated fungi (Colletotrichum, Botryosphaeria/Lasiodiplodia and others) entering through wounds and dead tips.
- Spread by air- and rain-splashed spores, entering pruning cuts, dead tips, sunburn and insect/mechanical wounds.
- Far worse on stressed, neglected, insect-damaged or drought-/nutrient-stressed trees.
- Often follows heavy or careless pruning and can be worse after a stressful season.
Cultural & organic control
- Keep trees vigorous and unstressed with balanced nutrition and proper irrigation — healthy trees resist die-back.
- Prune out affected shoots and branches well back into healthy wood, below the discoloured tissue.
- Prune in dry weather, remove and destroy the prunings, and disinfect tools between cuts.
- Manage insects and sunburn that create the wounds the fungi enter through.
Chemical control
- After pruning to healthy wood, protect the cut ends and cankers with a copper (Bordeaux) paste/fungicide.
- A protective fungicide spray on the flush and after pruning can reduce new infection where recommended.
- Combine chemicals with keeping the tree vigorous and with sanitation — sprays alone will not fix a stressed, neglected tree.
- Confirm the current pruning-paint and spray recommendation for your crop with your local KVK.
Prevent it coming back
- Keep trees vigorous and unstressed, and prune affected wood back to healthy tissue promptly, protecting the cuts.
- Prune in dry weather, disinfect tools, and remove and destroy dead and cankered wood.
- Manage insects and sunburn, and avoid heavy careless pruning that opens many wounds.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
My mango/citrus shoots are drying back from the tip and some branches have sunken cankers. What is it?
Shoots and branches drying from the tip inward, with browned twigs, dried hanging leaves and sunken cankers on the wood, are die-back and branch canker, caused by wound- and stress-associated fungi. They are worst on stressed, wounded or neglected trees. Prune the affected wood well back into healthy tissue, protect the cuts with copper paste, keep the tree vigorous with good nutrition and irrigation, and manage the insects and sunburn that open the wounds.
Why is die-back worse on stressed or neglected trees?
Because the fungi that cause die-back and canker are opportunists that take hold through wounds and dead tips and advance most easily in weak, stressed tissue. A vigorous, well-nourished, properly-irrigated tree resists and walls off the infection, while a drought-stressed, nutrient-deficient, insect-damaged or neglected tree cannot, so the die-back moves fast. That is why keeping trees healthy and unstressed — alongside pruning to healthy wood and protecting cuts — is the foundation of control.
How far back should I prune a die-back branch?
Prune well back into clearly healthy wood, below all the discoloured or cankered tissue — cutting only at the visibly dead tip leaves infected wood behind and the die-back simply continues. Cut into sound, unstained wood, prune in dry weather, disinfect your tools between cuts, protect the cut ends with a copper paste, and remove and destroy the prunings. Combine that with keeping the tree vigorous and managing wounds, and confirm the approach with your KVK.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.