Came across this from Ireland for those that are interested, it's an article
re-published (
I think) in Four Seasons, the newsletter for NIHBS (Ireland's equivalent of BIBBA),
originally published in An Beachaire, the newsletter for FIBKA (the Republics equivalent of BBKA),
taken from a ten year study at Ireland's Beekeeping Research Centre at Clonroche; I think this might be the published article from Clonroche, I'm not sure if it's been edited.
https://assets.gov.ie/133282/78b0646e-4286-4913-85ff-a6055bf9216f.pdf
Basically average annual yields are 31.7 kilos per hive from 1966 to 1977, in the south east of Ireland (probably one of the top places for honey bees, due to climate) the article states that "Irish bred black bees" were used. This is naturally before Varroa but after the island was re-populated with bees due to the IoWD.
The bees were kept according to the guidelines laid out in a leaflet called "A blueprint for profitable honey production" published by the Dept. of Agric. and Fisheries.
INTERESTING to note that the honey yields from Heather was an average of 3.2 kilos, not worth the trouble... which is strange, Brother Adam mentioned in one of his books that before WW2 he took his bees to the heather more than 50% of the time, after WW2 less than 50% of the time (depending on the weather and the stage of flowering, I guess???), but I thought that the Heather honey would have been one which the northern dark European bee should have excelled at, if it's supposed to be the best bee for Northern Europe (eps. for Britain and Ireland).