Rust fungus in cultured output (5)

I believe the answer is:

uredo

'rust fungus' is the definition.
(I've seen this before)

'in cultured output' is the wordplay.
'in' indicates a hidden word.
'UREDO' is hidden within 'cultured output'.

(Other definitions for uredo that I've seen before include "rust, in the garden" , "Rust fungus" .)

I've seen this clue in The Independent.

Want a hint initially instead of a full solution? Install my app