[JohnB47]

Hi.

Noticed today a first early (lady christl) looking very sick so I decided to dig it up. I found the root, starting about two inches below the surface, to be black,wet and rotten.

Any idea what migt have caused this and will it effect my other spuds (which all look healthy)?

Ta.

[nilsatis1964]

Have you a waterlogging problem?

[mumofstig]

Have a look
here on the potato disease site.

[solway cropper]

Was it just the seed potato that you planted?

Once they've given their energy to the new plant they go black and rotten but don't normally affect the rest of the plant.

Could be blackleg which is caused by a virus.

[JohnB47]

Thanks folks. No water logging problem. Good link mumofstig. I think you're correct solway cropper. Looks like it had blackleg to me. Not sure what you mean by "Was it just the seed potato that you planted". I've planted three rows of first and second earlies. This one was in the middle.

Hopefully just that one spud.

Cheers.

[Yorkie]

The original seed spud provides the initial energy for the plant to start growing.  Once it's done its job, it rots off and thus can fit your description.