Definition of "paddymelon"

Not even an occasional clod of earth stowed in the middle of a sack, or a few hefty paddy-melons, could make the toil profitable.

1941, Kylie Tennant, The Battlers

The road was a straight band of tarmac and, on either side, there were strips of red dirt with paddy-melon growing over them.

1987, Bruce Chatwin, The Songlines, Vintage, published 1998, page 76