Grain crop — pressure to replace British — confer (6)
I believe the answer is:
parley
'confer' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
(Other definitions for parley that I've seen before include "Colloquy" , "discussion" , "Speak with another" , "Negotiation between enemies" , "Negotiate" .)