Allotments 4 All

I've dug up a couple of my Rocket plants which have been fine.  Got to the next one in the row today and all the tubers are diseased.  I thought initially they looked blighted but I think it's way too early and the haulms are healthy.

The problem seems to start with brown discolouration around the stalk area of the tuber which looks like it causes it to split open and rot as the tuber swells.  The potatoes are all mis-shapen, small, flattened, sort of pumpkin shape.

Any ideas?

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I would say it is potato spraing which can be present in the soil. It just seems to effect some areas and then everything else is fine.

Thanks Tattieman.  I've been googling and I'm not sure about the spraing.  The affected tubers don't have the brown markings inside.  Found the Potato Council's website (great for id on pests, diseases and conditions btw) and these are the best I can match to:

http://www.potato.org.uk/department/knowledge_transfer/pests_and_diseases/ref.html?item=49

and this one:

http://www.potato.org.uk/department/knowledge_transfer/pests_and_diseases/ref.html?item=34

Might send the picture to Alan Roman and see what they say.

They look like they have been in a bad drought.

what about watery wound rot

Yeah send it to Alan and tell him this is the crop you got off his seed ;D
You should get a quick reply ;)

Looks like 'Blackleg' to me

see here; http://www.potato.org.uk/department/knowledge_transfer/pests_and_diseases/ref.html?item=11

I think we should all agree that it is a case of spraing with vascular browning and a touch of blackleg with watery wound rot thrown in for good measure ;D
It is a strange thing as Rocket have good resistance to spraing and blackleg. They can crack and split if they are left to mature.
It shouldn't be blackleg if the haulm was healthy.