Try coating your seed taters with a little garden sulfer before you plant them. Shake and bake in a bag style, and they will resist the little soil creatures much better. But then you have quite a history of rotting taters in Ireland if I remember my history right.

Does the garden sulphur protect the mother potato only or also the crop as a whole?
Anyone have an idea about why the potatoes get a bad taste after they have been left in the ground a while and have started to sprout?

Lucy, I find it quite remarkable to be responding to a question from Ireland on Irish potatoes . . .

Gathering my American wits about me, bolstered by American academic authority: "Associated with greening, bitter and toxic glycoalkaloids, such as solanine, are formed. Solanine also forms in response to bruising, wounding (including fresh processing followed by storage), and during sprouting. Glycoalkaloids are heat stable and minimally impacted by cooking."

So, both light and sprouting causes the formation of solanine which is bitter and toxic. It does not break down during cooking.

Here's as authoritative an American source as I can think of (the University of Idaho) on alternative organic methods of sprout suppression. Note that "After mid-winter, nearly all potatoes available in commercial markets have been treated with a chemical sprout inhibitor":

Here is a link that might be useful: Potato Sprout Control in Storage - pdf

To add a few more thoughts - notice the quote on the formation of solanine is from information on very early potato crops. So, your ideas on the sprouting of late and early varieties are probably quite accurate.

From my own experience, I know a person who sells potatoes at farmers' markets. He will remove sprouts by hand in storage. I don't know if this is specifically to suppress the sprouts because of the potential deterioration of the potatoes or to simply make them more marketable. I know that he doesn't like to do this.

Storage temperatures are fairly critical to good quality and the UCDavis suggests for table use that they remain at 7°C (45°F) with 98% relative humidity. However, "Storing immature potatoes below 10-13°C (50-55°F) for as few as 3 days may cause the accumulation of reducing sugars leading to excessive browning during frying/chipping." I know that in storage, temperatures can be reduced - slowly. Apparently, slowly reducing the temperatures is necessary to limit that starch to sugar conversion. Probably, 45°F and above is a good general rule but lower temperatures will inhibit sprouting.

Steve

I would have thought that storing tubers in the ground would be a good plan in ireland as the ground never freezes hard there. It sounds though that the problem is that the ground does not get cold enough quickly enough to suppress sprouting from the matured tubers - especially a problem if the ground is moist also. I sometimes have that problem here, though every winter tubers get through un-sprouted and un-frozen - I find them in early spring when I am making up beds. They are usually in excellent condition, better than those kept in my root cellar.

Yes that is the situation.This year the autumn has been particularly mild and so some of the varieties are sprouting already.
So my plan is to lift them before the new sprouts get to any size and then rebury them together in the same bed-after rubbing off any new shoots.

I am a bit confused as to the optimum conditiions for storing as digit in the previous post indicates 98% relative humidity as perfect .Wouldn't that more or less correspond to wet soil if they were buried like I am suggesting?

Actually I suppose I should be making a proper potato clamp but have been too lazy
http://www.selfsufficientish.com/clamp.htm

Lucy, your soil temperature may be of the greater concern. If you still have insects (or arthropod millipedes, anyway) and slugs active, the soil temperatures must be fairly high. And I believe that above 45°F, the tuber begins to grow.

My carrots are stored in a hole sitting upright, cheek-to-jowl, and covered first with soil and then leaves. They do better there than in the refrigerator.

I like that potato clamp site - nice clear info. Since the U of Idaho has found that, "Oils of some herbs and spicesÂessential oilsÂhave been shown to reduce sprouting in potatoes" and they are using spearmint and peppermint oils, maybe the use of mint leaves in a clamp would inhibit sprouting. Never seen anything about this but it certainly seems reasonable to me. It looks that from the linked charts, sprouting was suppressed by 60 Â 70% or more using mint oils.

Steve's digits

Maybe I should have said that "sprouting was suppressed significantly using mint oils." Never should trust myself in using math more complex than counting.

Anyway, after months of storage, the weight of the sprouts from treated potatoes was less than untreated potato sprouts.

S

That's interesting. I have tons of unwanted mint in the garden to experiment with.