South Africa must produce a fruit (7)
I believe the answer is:
satsuma
'fruit' is the definition.
(satsuma is a kind of fruit)
'south africa must produce a' is the wordplay.
'south africa' becomes 'sa' (abbreviation).
'produce' indicates anagramming the letters.
'must' with letters rearranged gives 'tsum'.
'sa'+'tsum'+'a'='SATSUMA'
(Other definitions for satsuma that I've seen before include "A small citrus fruit" , "Orange, district and style of Japanese pottery" , "Small, easily-peeled orange" , "Type of tangerine" , "sort of orange" .)