Help - rotting Sarpo Mira !

[roosky]

We have grown Sarpo Mira for a few years now, with great success, originally with bought seed, but the last 2 years with our own.
This year, the large potatoes look wonderful, but when they are opened up, they are either rotten, or beginning to rot. from the middle out. Occasionally, we find a show which is totally rotten. Is this how blight behaves?

[ConstantGardener]

Hiya, I think you might have left them in the ground too long - to quote from one website I found:

4.The tops do not die off after flowing like other varieties so do not wait for that to happen before lifting. (They can continue flowering for weeks!) Check regularly and harvest when the tubers are the size you want. I would advise against leaving them into the ground until autumn as the tubers can become massive and hollow.

Blight is usually apparent through discoloured patches on the skin - a kind of hard rot which when you slice open the tuber sometimes extends into the core but I've never seen it working from core outwards. Usually by the time it's in the tubers all you find is a smelly mess anyway. And I've never, in many years now of growing Sarpo Mira, ever known a single tuber infected - even in 2012 when the blight was as bad as I've ever known it.

[Potstubsdustbins]

Sounds like 'hollow heart' to me. This is usually caused by a long wet spell after dry weather, the plants should be well watered during dry weather to prevent this.

Potty

[Bill HH]

I agree, a blighted tuber rots from the outside in, the surface goes soft and smelly.

[WendyC]

I agree, a blighted tuber rots from the outside in, the surface goes soft and smelly.

Really smelly!!