The eccentric Mr Dale's fruit tree (6)
I believe the answer is:
medlar
'fruit tree' is the definition.
(I know that medlar is a type of fruit tree)
'the eccentric mr dale's' is the wordplay.
'the eccentric' is an anagram indicator.
'mr'+'dale'='mrdale'
'mrdale' is an anagram of 'MEDLAR'.
(Other definitions for medlar that I've seen before include "Apple-like fruit" , "Led ram (anag) - fruit related to the apple" , "Red Mal turns to the fruit tree" , "Dermal (anag.)" .)