Ship with cargo of sweet vegetables (5)
I believe the answer is:
spuds
'vegetables' is the definition.
(spud is a kind of vegetable)
'ship with cargo of sweet' is the wordplay.
'ship' becomes 'SS' (prefix in ship names eg SS Great Britain).
'with cargo of' is an insertion indicator.
'sweet' becomes 'pud' (pud is a kind of sweet).
'ss' going around 'pud' is 'SPUDS'.
(Other definitions for spuds that I've seen before include "Potatoes (informal)" , "Potatoes (colloq.)" .)