Some people put the tube right under the tree when they plant it to make the roots grow deep towards the water and that way the tree grows much faster, so it's a good thing that the tube is close to the tree.

Read: Gardening with less water, in the book if it is a seedling you want it close, if the tree is more mature and established you have to slowly transition from whatever system you are using to the deep watering method, and it depends on the tree, the zone, etc. Also, he recommended drilling holes that will be facing the tree (marking PVC as where those wholes are), the main emphasis of the book is to water with less, up to 90% less in some cases.