canker of tea tree

例句：

1. 1. The farmer's canker has spread to the neighboring fields.
   农民的病根已经蔓延到邻近的田地。
2. 2. The wound on his arm is turning into a canker.
   他手臂上的伤口正在变成疮痂。
3. 3. The disease is caused by a canker in the plant.
   这种疾病是由植物中的疮痂引起的。