Put to part of cereal plant, can it cut? (5)
I believe the answer is:
shear
'cut?' is the definition.
(shearing is a kind of cutting)
'put to part of cereal plant can it' is the wordplay.
'put to' is a charade indicator (letters next to each other).
'part of cereal plant' becomes 'ear' (as in an ear of corn).
'can it' becomes 'sh' ('can it' can mean stop talking or be quiet).
'ear' after 'sh' is 'SHEAR'.
(Other definitions for shear that I've seen before include "Clip a sheep" , "Cut with clippers" , "Barber" , "Cutter" , "Cut wool off (a sheep)" .)