[mumofstig]

I just find it a bit strange that we'll put supermarket potato's in our stomachs but not our ground-they must be certified disease free?

Most of the time you cut them up to cook them, so you cut out any bad bits as you find them 
and sometimes jacket spuds have black bits in when you've cooked them - so we can't say that they're disease free from the supermarket, can we?

[Trillium]

In Canada we often use our own potatoes for seeds, BUT, we don't have even a small percent of the disease problems the UK does. And potato blight is so rare here that I had to look up what it was when it first happened a few years ago. Thankfully, it hasn't returned.

That said, even with careful choosing of our own potatoes and very regular rotation, we still find we must use fresh certified seed potatoes every few years as we notice our variety of scab start to return.

As for using store potatoes, they're so weakened with chemical fertilizers, herbicides and pesticides that they don't grow particularly healthy plants despite our best efforts and almost always are the ones that attract pests like the potato beetle and garden fleas. Homegrown spuds tend not to attract pests so much. And yes, the potato beetle is appearing in the UK.

[Salmo]

It was always a farming practice to buy in a small amount of good certified seed each year and save any undersized potatoes from that crop for seed the next year. This was referred to as "once grown". Many small growers used to buy "once grown" seed from their larger neighbours to save money.

What the current position is on farms I have no idea.

I see no reason not to save a few "once grown" from a healthy crop to grow the next year but not beyond that.

[Totty]

The choice of different seed potatoes alone should be reason to buy them. You are very limited to varieties in the supermarket compared to seed catalogues. I was under the impression that the majority of seed spuds were grown in scotland, because due to the lower temperature, they are far less prone to harbouring desiese that will show itself next year. A potato also needs a dormant period to become a seed potato, cold and dark for a few weeks before planting will be a success.
 By all means try a few of a variety you particularly like from the market but dont be suprised if all does not turn out well.

Totty

[DD.]

I was under the impression that the majority of seed spuds were grown in scotland, because due to the lower temperature,

Transmission of diseases via aphids is one of the main problems. Aphids are not so prevalent in the areas of Scotland in which seed spuds are grown.

[Lawrence]

It was always a farming practice to buy in a small amount of good certified seed each year and save any undersized potatoes from that crop for seed the next year. This was referred to as "once grown". Many small growers used to buy "once grown" seed from their larger neighbours to save money.

What the current position is on farms I have no idea.

I see no reason not to save a few "once grown" from a healthy crop to grow the next year but not beyond that.

Now you mention it I think that is what the grower was talking about.
I tried an internet  search without much joy, but I did find a reference to 2nd to 5th generation seed potatoes being the best, I am sure that must depend on your location.
I personally would only grow from  fresh seed, but I have had some good surprise results from the odd spud I missed digging up.


edited to fix quote

[sootyfaestoney]

cheers for all that.
I will be gettin proper seed tatties as we had a guy at the allotment meeting who actually is the tester for the seed tatties, he the bloke that goes round the seed tattie producers and tests them for their cert for selling. It is a hard test as they have to be zero infection in a huge amount to be classed as free, but any probs and they drop a cert for a good while. so the seed tatties would be a better option I think in the ground, but it is a good idea to plant at house in containers, cheers again.

[Bing]

But a perfect seed potato does not guarantee a perfect crop. Soil / wheater etc can still affact the crop.

[DD.]

Indeed, but why not give them the best chance possible - right at the start?

In any case, we're talking transmission of disease here, not growing conditions.