well, since someone brought up the 'Mother Country', here is what the OED has to say about nubbin:

[f. nub n.1]
A dwarfed or imperfect ear of maize. Also transf. and fig., esp. something small or something that remains when the main part is worn away.

...and a citation or two:

1692 in Maryland Hist. Mag. (1918) XIII. 209 Jones saw him buy one beaver skin...for thirty ears and nubbins of corn. 1954 Dylan Thomas Quite Early One Morning i. 56 The Telecinema... blobs and nubbins and rubbery squirls receding.