Further to my earlier article on Common Scab and as a reply to Simon Smith, I did a trial last Spring on two Kestrel potatoes that had scab, one had far too much scab on for exhibition and the other was even worse and just fit for pigs!
I planted both in my own potato mixture and in the usual poly bags with nothing else added. They were positioned as the first two bags in the rows so that I could really monitor how dry the bags were. They were kept evenly moist throughout and the resulting crop were lovely and clean.
So it must prove that the common scab doesn’t pass on from seed potatoes to the following crop. One bag had a smaller quantity than the other but I could have had a decent set for a good local show. Other factors of course can affect the scab such as a high PH in either your soil or compost, or obviously leaving them dry at the potato development or initiation stage.