User blog comment:KidVegeta/Canonicity/@comment-3097771-20101130081759

(3)

Tree of Might is non canon, due to it's timeline overlooking. This movie could not have taken place, as it's timeline area is supposed to be after the Vegeta Saga. However, immediately after that saga all characters left for Namek. Characters such as Tien and Piccolo could also not be alive during that time period. Timeline errors are severe canon breaking material, and can not be overlooked.

Final Ruling: Not canon