Second crop ruined at the farm (9)
I believe the answer is:
aftermath
'second crop' is the definition.
(I've seen this before)
'ruined at the farm' is the wordplay.
'ruined' is an anagram indicator.
'at'+'the'+'farm'='atthefarm'
'atthefarm' with letters rearranged gives 'AFTERMATH'.
(Other definitions for aftermath that I've seen before include "Subsequent consequences" , "Repercussions" , "Subsequent circumstances" , "Subsequent consequence" , "Circumstances that follow as a result of something" .)