In this section:
Crown Gall
Cause
Bacterium Agrobacterium tumefaciens
Affected
Most common in peaches, but all stone fruit can be affected.
Symptoms
Galls are produced on the crowns of the root system, ie at base of trunk, and to a lesser extent on the smaller roots of trees. Initially the galls are creamy coloured and soft, but as they grow they become darker and woody. The tops of severely affected trees are weak and stunted and the leaves are often pale in colour and tinted with red. Infected trees are frequently blown over due to lack of anchorage from the infected root system.
Conditions favouring
The bacteria live in nursery and orchard soils and infect young trees through wounds to the crown or roots of the tree. Incidence is most common in light sandy soils.
Control
Control during propagation is essential. Trees should be inspected for presence of galls prior to purchase or planting. Infected trees should be burnt.
In high risk (sandy soils), trees should be dipped in anti-gall inoculant at the time of planting in the field. This simple and cheap operation will protect the trees for life.
