Ron, lucky you getting great yields of potatoes using no-dig, it is the one vegetable I find challenging to replicate the results of digging a trench, possibly as I usually filled the trench with manure and comfrey leaves to surround the tuber with goodness.
This year was completely arid in NW London from sow date to harvest of first earlies, save a monsoon in May of 4 inches in 36 hrs. I watered regularly, but the yields were dreadful. At least with Foremost, I know it was not the seed potatoes as five 12 litre pots sown with one tuber each yielded 2lbs+ from mid May to mid June.
Four years ago, I grew earlies in the same spot and had good yields, the last time that area was dug.
I am trying maincrop this year too, so I hope they are better….