Agriculture Reference
In-Depth Information
Fig 11.11 A small gall canker caused by
Tubercularia lateritia
developing on a macadamia trunk.
the bark a completely sloughed-off or irregular shape.
Fungal structures often appear on the canker as
creamy-white or orange pinhead-shaped fruiting
bodies.
Source of infection and spread
Both the asexual and sexual stages of the fungus are widely
distributed in tropical and subtropical regions. The fungus
is one of the most conspicuous and common nectrioid
fungi occurring on recently killed dicotyledonous wood;
they cause disease in other tropical crops. The fungus
enters the plant through wounds.
Fig 11.10 A young tree affected by trunk canker. Advanced canker
can cause stem girdling and tree death.
Increase the organic matter content in the soil.
•
Excise small cankers thoroughly and apply a wound
dressing to control early infections.
•
Spray the lower trunk with recommended fungicides
before the wet season.
•
GALL-CANKER
■
Cause
The fungus
Tubercularia lateritia
.
Symptoms
Symptoms include canker with callus or gall formation
on the main trunk, branches and exposed roots. In
some cases, gum exudates occur on diseased parts. The
underlying parts of the galls are darkened and the tissue
is discoloured. The galls sometimes coalesce, giving
Fig 11.12 A large gall canker on a macadamia trunk.
