Post blight treatment

[carosanto]

I had a super crop of Maris Piper coming about 3 weeks ago, absolutely so healthy and green  and I tended them faithfully, watering throughout the very hot and dry spell we had back then.  Then along came some very damp weather, and hey presto, blight.  As always here in Cornwall, it was only to be expected.

I cut the foliage back to the ground, and since then, of course, the weather has been nothing but dry and sunny (wonderful).  But should I be still watering my now defoliated potatoes?  I had a firkle two weeks ago and the tubers were fair sized, and appeared unaffected by blight, I Have been watering, but feel a bit silly watering an empty plot!  Will potato tubers swell without top foliage, should I water, or cut my losses and harvest what I can.  Post blight advice help please, and thanks in advance for any help forthcoming.  These are the first main crop potatoes I have ever grown, sticking mostly to earlies because of the blight problem we have here.

[carosanto]

[BarriedaleNick]

I'd be tempted to pull them or maybe half of them.  Watering now could cause them to rot - there is no foliage to make more starch so they wont swell much more I wouldn't think. 

[Unwashed]

I'm in the same situation, though I haven't been watering.  I'm going to lift what tatties I have, because I don't think they'll get any bigger and I don't want the blight spores washing down and affecting the tubers.

[Kepouros]

Once the foliage is removed the tubers will not grow any more, but the plants will start to `set` the skins.  This process takes a couple of weeks or so, during which time the tubers should remain undisturbed - if they are lifted too soon the skins will be too soft and easily damaged, and the tubers will not keep properly.  Where the plants have been blighted ALL the old foliage litter should be carefully removed as soon as it is cut down and the tubers should be left in the ground for an extra week (3 weeks altogether) to allow any blight spores left on the soil surface to die, after which it is safe to lift the crop.

Once the foliage has been removed from a blighted crop it is unlikely that blight spores on the soil surface will be washed down to the crop if they have been properly earthed - blighted tubers are usually the result of the blight travelling back down the stems because the blighted haulm has been left on for too long, or as a result of the crop being lifted TOO SOON - while there are still live blight spores on the soil surface - hence the need to leave them in the ground for 3 weeks from haulm removal.

[bcday]

What Kepouros said! 
Leave them in the ground for the next few weeks. No watering. The skins need to cure and harden. No more firkles either, lest you carry live spores down to the tubers on your fingers. If you want some of the tubers for dinner before the 3 weeks time is up, plan on cooking them very soon after you lift them.