A rotten crop -- it is fruit (7)
I believe the answer is:
apricot
'is fruit' is the definition.
(type of fruit)
'a rotten crop it' is the wordplay.
'rotten' indicates an anagram.
'crop'+'it'='cropit'
'cropit' is an anagram of 'pricot'.
'a'+'pricot'='APRICOT'
(Other definitions for apricot that I've seen before include "Orange fruit" , "Orange-yellow fruit in plum family" , "Stoned fruit" , "tree" , "Orange-yellow colour; fruit" .)