Bark injuries serve as entrances for canker pathogens.

Bark injuries serve as entrances for canker pathogens.

• A. True
• B. False
• C. Sometimes
• D. Never

Answer: (A)

Bark injuries provide openings for canker pathogens to enter. When the bark and underlying cambium are damaged, the protective barrier is breached, creating wounds that are prime entry points for fungi and sometimes bacteria that cause cankers. These pathogens take advantage of the moist, exposed tissue to colonize the cambial zone and nearby sapwood. Once inside, they disrupt nutrient and water transport, forming sunken, discolored cankers that can girdle branches or trunks and weaken the plant. Stressful conditions such as extended wet weather, heat, or drought-induced vigor loss after a wound further raise infection risk. Without a wound, many canker-causing organisms have a hard time penetrating healthy tissue, so injuries are a major factor in canker development.

Bark injuries provide openings for canker pathogens to enter. When the bark and underlying cambium are damaged, the protective barrier is breached, creating wounds that are prime entry points for fungi and sometimes bacteria that cause cankers. These pathogens take advantage of the moist, exposed tissue to colonize the cambial zone and nearby sapwood. Once inside, they disrupt nutrient and water transport, forming sunken, discolored cankers that can girdle branches or trunks and weaken the plant. Stressful conditions such as extended wet weather, heat, or drought-induced vigor loss after a wound further raise infection risk. Without a wound, many canker-causing organisms have a hard time penetrating healthy tissue, so injuries are a major factor in canker development.