No elm produces fruit (5)
I believe the answer is:
lemon
'fruit' is the definition.
(lemon is a kind of fruit)
'no elm produces' is the wordplay.
'produces' indicates anagramming the letters.
'no'+'elm'='noelm'
'noelm' is an anagram of 'LEMON'.
(Other definitions for lemon that I've seen before include "Fruit-tree" , "Dab" , "Washout" , "Feeble thing (colloq.); fruit tree" , "Acidic fruit" .)