Dwelly has dlòth: “Handful of corn or grass cut with one stroke of the reaping hook.” A similar use is seen in Mull man John Macfadyen’s book of 1890, An t-Eileanach: “he said, with the last dlòth in his hand”
It also features in Mo Reul Iùil, in Smuaintean fo Éiseabhal by Dòmhnall Aonghais Bhàin: “You have beautiful curly locks / Like corn marigolds / In smooth arches / And the comb putting it an dlòth”
I have only heard locally of dlùthadh, for collecting the corn, rather than dlòth, although they are clearly connected.
Faclan bhon t-Sluagh gives three different uses of dlòth: twice in South Uist it’s used to mean that the stubble is of even length after scything the corn. Two uses in North Uist and Lewis refer to dlòth as a handful of cut corn. One use recorded in Antigonish, Cape Breton is closest to Fr Allan’s meaning in 119: “air a dhlòth e.g. grain laid in an orderly swathe after the mower.”