Greek letter with afterword naming what citrus grower might require (4)
I believe the answer is:
pips
'citrus grower might require' is the definition.
I can't tell whether this defines the answer.
'greek letter with afterword naming' is the wordplay.
'greek letter' becomes 'pi' (letter from the Greek alphabet).
'with' says to put letters next to each other.
'afterword naming' becomes 'ps' (I can't justify this - if you can you should give a lot more credence to this answer).
'pi'+'ps'='PIPS'
'what' is the link.
Can you help me to learn more?
(Other definitions for pips that I've seen before include "Hard seeds in fruit" , "Small fruit seeds" , "Just beats, maybe at the post" .)