Fruit, two-thirds produced in south (7)
I believe the answer is:
raisins
'fruit' is the definition.
(I've seen this before)
'two-thirds produced in south' is the wordplay.
I cannot really see how this works, but
'in' is found in the answer.
'south' could be 's' (abbreviation) and 's' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for raisins that I've seen before include "Dried grapes, nice in cakes" , "Fruit that's dried" , "Dried grapes used in cakes" .)