I assume the 'harvesters' mentioned in this poem, were the potato harvesters, who used to come across in large numbers each year, just for this harvest.

There is a verse from my childhood which seems to prove this.

To the tune of the Gallant 42nd


Wha' saw the tattie howkers,
Wha' saw them gang awa'?
Wha' saw the tattie howkers,
Marching doon the Broomielaw?
Some of them had bits an' stockin's,
Some of them had nane at a',
Some of them had umberellas
Marching doon the Broomielaw.

BBC programme on the Irish migrant workers phenomenon.

JM