which potato disease?

[Snow]

So a few of my potatoes have started getting brown splotches the last couple of days, followed by yellowing of the leaves (all leaves are not as green, and a few very yellow) and the stalks are now turning brown. It seems to be happening quite rapidly.


Too early for late blight, surely. Must be too early to be dying back, even for earlies? They are Dunluce and have been in the ground 11 weeks and 3 days.

So what is it, and what to do? I may cut these few down now, so as to limit the chance of everything getting struck. These are earlies so due to be dug up in a couple of weeks anyway. I guess I might get some marbles earlier than planned.

[Penellype]

If they are earlies and have been in 11 weeks they could be simply dying back naturally. Some of my Rocket look a bit like that, and they are ready for harvest. Why not have a furtle and see what size the potatoes are, then decide whether to harvest them or leave them a bit longer. It doesn't look like blight as far as I can tell from your picture.

[Martin H]

I can't believe it's blight, it hasn't been warm enough or humid enough (until today, anyway). The leaves on earlies always seem to get brown blotches and go yellow as they ripen.

BUT I really don't like the look of those brown stems. So I would cut off the foliage of any with infected stems and keep a close eye on the rest.

[Thelma Sanders]

Dunluce should be ready to eat about now, as already said.

[roitelet]

What do the underside of the leaves look like?

[Greenleaves]

Could it be potato black leg caused by excessive watering? Brown stems and yellowing leaves fits the bill......might be a million miles away but just a thought

[Snow]

Could be black leg, perhaps. They have been watered, but then it has been very hot and dry here, so they shouldn't have had too much.

Only seems to be the Dunluce, so could be that they are just ready, but non of the other first earlies are ready yet and the others went in 2 days earlier (not that that would make much difference).

Thanks for the helpful replies. The surprising thing is how quickly they seem to be getting worse. Didn't see anything wrong with the stems yesterday, so very quick change there and that's the bit I don't like the look of. Underside of the leaves looks the same really, some brown blotches. I've cut them down to the ground level tonight. In a few days I'll dig them up and see what I have. Hopefully the others will all be alright. I was probably going to harvest one of the others in about a week to start spreading the harvest out, so not the end of the world, probably.

[Potstubsdustbins]

Black leg a disease by the way usually starts at or below ground level then affects the leaves.

[fishpond]

It isn't blight.
You really should dig one up and look at the spuds.

[Snow]

Black leg a disease by the way usually starts at or below ground level then affects the leaves.

Thanks, I'll report back what I find underground. Would have dug them today but it was raining for a change.

[Snow]

Not blackleg. No disease underground. Tubers look fine. May have just been the plants starting to die back, but who knows. Anyway, all of these Dunluce are out the ground now.


Fewer than I had hoped for - 1.463kg from three or four plants ( I also stole two spuds from one of these plants last week, weighing another 87g) - but given it was less than 12 weeks, it's actually pretty good. Is there a more wonderful sight in the garden?