Where does the Fire Blight bacteria over-winter?

The Fire Blight bacteria, specifically Erwinia amylovora, over-winters in cankers on infected plants. Cankers are sunken, dead areas of bark that can form on branches or trunks, especially in apple and pear trees. During colder months, the bacteria reside within these cankers, surviving the winter and re-emerging when conditions become favorable for growth, typically in spring.

The presence of the bacteria in cankers allows them to initiate new infections when the tree begins to grow again, leading to the spread of Fire Blight. Understanding the survival mechanism of this bacteria is critical for effective management and control of the disease in orchards.

While the other locations mentioned are possible areas where different pathogens might survive, the specific context of Fire Blight points primarily to cankers as the main over-wintering sites for this particular bacterium.