What are cankers indicative of regarding Fire Blight?

Cankers are indicative of areas where bacteria can overwinter in the context of Fire Blight, which is a bacterial disease primarily affecting apple and pear trees. When Fire Blight strikes a tree, the bacteria can infect the plant tissues, leading to the development of cankers, which appear as sunken, darkened areas on stems and branches. These cankers provide a protected environment where the bacteria survive through harsh conditions, allowing them to re-emerge and infect the tree during the following growing season.

The presence of cankers is vital for the life cycle of the Fire Blight bacteria; understanding this relationship helps in managing the disease. Effective management includes pruning affected areas during dry weather to remove the cankers and reduce the bacterial load in the environment. Recognizing that cankers indicate overwintering spots for the bacteria is essential for proper disease control and prevention strategies.