Cavity Work (Cankers)
Cankers are dead sections of bark on branches or main trunks of trees. If the trunk is affected, the entire plant may die. Canker disease and cankers caused by mechanical injuries may not kill trees outright but can cause wood-rotting. Wood decay leads to weak branches which are hazardous. Every attempt should be made to prevent cankers from developing. When cankers do appear, proper care can prevent further damage.