Is this blight

[Marb67]

The weather has been cool but had a few drizzly days so hopefully this isn't potato blight as it needs to be warm too. What can this be please as it's only on a small part of the plant. I think its old Red Duke of York that were planted some time ago and have re-surfaced from the odd spud. I cut quite a bit of the foliage away last week as it shades my outdoor toms.

Please don't tell me it's blight.

[ameno]

Pretty certain that's not blight. Or at least not late blight, the damaging one.

There are actually two potato diseases called "blight".
Late blight is the one you need to worry about - it causes large, irregular patches of dark grey-brown damage and spreads very quickly, also attacking the stems and the tubers underground.
What you have there looks to be early blight, actually a completely unrelated disease. It causes small circular brown dead patches on leaves, and that's pretty much it. It will not spread to the stems or tubers. In a very bad year it can potentially defoliate a plant and therefore cause a reduction in yield, but that's the worst it ever gets. And early blight thrives more in hot, dry conditions, so it doesn't really take hold that much in this country (unlike late blight, which likes merely warm and damp conditions).

It's naive it think blight only spreads when the weather is particularly damp or warm, though.
Those are merely relative measures, and in reality in this country, unless you live in a dry part of the South East then the conditions for blight spreading (over 10c and 90% humidity for several hours) will be met six out of seven days a week all summer. It's basically always warm enough, and on warm days you very often get a heavy dew the following night, which is more than enough to allow blight to spread (you probably don't see it because it has all evaporated again within an hour after dawn).

[Marb67]

ok, thanks. I have such a small greenhouse I will have to put some of my toms out in the garden which is a huge risk.

[quanglewangle]

I can only see Marb67 's picture if I log out. That is, while I am logged out I can see it. Can't see any sign of a picture while I'm logged in.

[Snoop Puss]

I can only see Marb67 's picture if I log out. That is, while I am logged out I can see it. Can't see any sign of a picture while I'm logged in.

QW, maybe post your problem on this thread: https://www.growfruitandveg.co.uk/gr...ht#post2548725
It seems to be a general thread for site issues.

[Marb67]

Well, these are now going downhill but it can't be blight as too cold and out of blight season. They have been under plastic out in the garden. No ide why suddenly going downhill 😵

[Plot70]

That looks very blighted.
On my plot the blight has been mild and has only spread through three plants in a row by a path.
Removing affected branches has worked much better than in past growing seasons.

[greenishfing]

Hate to say it, but it looks suspiciously like blight to me. But someone might know better.

[Marb67]

It cant be blight as you don't get it this time of year.

[ameno]

It cant be blight as you don't get it this time of year.

Dunno where you heard that, but it's nonsense. You absolutely do, especially as we've had such a mild (and damp) October.

[Nicos]

I’d go with blight too marb. I ‘ve had it often enough. You can smell it when you cut into the browned tomatoes.
Yes it’s late in the year but it’ll be much warmer too under plastic.

[Marb67]

It has been very cold here in Cheshire at night and in the day so again, I really don't think it can be blight which is a Summer fungus.

[Mr Bones]

Looks like blight to me too. Took a few plants out yesterday that had just started with it.

[MelanieSW]

My tomatoes have now started to get blight as well - it's now damp and still not too cold, so it's not surprising. Usually I'd have them cleared by now (outdoors), but I was hoping to get a few more. Alas, I think that's the end of the season.

[Marb67]

Well I had them covered which should protect. Just hope the greenhouse ones are OK.