It could produce a crop of casualties, of course (5,2,6)

'crop of casualties of course' is the definition.
The definition and answer can be both locations as well as being singular nouns.
Perhaps you can see a link between them that I don't see?

'it could produce a' is the wordplay.
I cannot really see how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
'produce' could be 'do' (I've seen this in other clues) and 'do' is found in the answer.
'a' is found in the answer.
This explanation may well be incorrect...

Can you help me to learn more?