Is It Blight?

[Penellype]

It does look as though it could be. I don't think diagnosis is that easy in the early stages - the potato council blight incidents page Fight Against Blight - Blight Incidents | Potato Council appears to have to confirm reported incidents and some of these do test clear. The best thing to do is definitely to remove and burn affected foliage.

[Scarlet]

It hasn't been the weather for blight. Wet and warm are blight conditions ....we haven't had rain down here for several weeks.

[Marb67]

We have had humid weather last week. I have put them in the waste recycle bin.

[Scarlet]

You can eat the spuds.. It won't have affected the roots yet. Humid is a bit different to rain. The pic you posted definitely didn't look like blight.

[the beadle]

I spent my 60th birthday last week, tearing down my potatoes as they'd all got blight. I'm on a site where there are 200 full size plots and we've all been hit. I dug them up today most of them look OK thankfully. Such a shame though, I do love my spuds.

[BertieFox]

Having had potato blight several weeks ago I immediately removed all the top growth and harvested the potatoes, spraying the outside toms at the same time with Bordeaux mixture. As the weather has been fairly sunny since, they are looking ok though I've removed the odd leaf and taken out a plant or two which clearly had it.

My real worry is what to do about the polytunnel. I was amazed it had spread there as I have never had that happen before in 11 years of growing tomatoes in this tunnel. I still can't work out how it got there.

What is the most likely agency for spread? I WAS using an overhead watering system using well water, but I can't think that would introduce blight, though it might have made the plants susceptible. Could it have spread on my hands or clothes?

I have taken out all the plants where the fruit was growing brown, and removed all the blighted leaves on the others. But every day, sometimes twice a day, I find more leaves turning the characteristic 'blighty brown', even on the cherry types which are the last to go.

I usually compost everything and although blight is not supposed to survive in the compost, could this be a means of introduction? There were also a lot of tomato seedlings coming up in the polytunnel soil from last year's crop... which I soon pulled out.

Any advice about how I can avoid this happening in future years would be welcome. I've always had the polytunnel to fall back on when blight strikes the outdoor ones, but now this has happened, I wonder if my days of growing tomatoes are under threat!

[Bill HH]

I had blight last year in the potatoes which then spread to an outside tomato and finally into my green house tomatoes. This year my policy has been to grow early potatoes and plant them early too so they are done before blight strikes. And then second early Orla which are supposed to have a measure of resistance and despite being covered in tiny spots seem to have survived blight, and finally my main crop is Sarpo Mira which is blight resistant. I would prefer other varieties (although the Orla taste superb) but will stick with this until I have been blight free for several years. As for the toms I completely gutted the green house, disinfected it and used a sulphur candle. So far the tomes seem ok.

[Penellype]

Having had potato blight several weeks ago I immediately removed all the top growth and harvested the potatoes, spraying the outside toms at the same time with Bordeaux mixture. As the weather has been fairly sunny since, they are looking ok though I've removed the odd leaf and taken out a plant or two which clearly had it.

My real worry is what to do about the polytunnel. I was amazed it had spread there as I have never had that happen before in 11 years of growing tomatoes in this tunnel. I still can't work out how it got there.

What is the most likely agency for spread? I WAS using an overhead watering system using well water, but I can't think that would introduce blight, though it might have made the plants susceptible. Could it have spread on my hands or clothes?

I have taken out all the plants where the fruit was growing brown, and removed all the blighted leaves on the others. But every day, sometimes twice a day, I find more leaves turning the characteristic 'blighty brown', even on the cherry types which are the last to go.

I usually compost everything and although blight is not supposed to survive in the compost, could this be a means of introduction? There were also a lot of tomato seedlings coming up in the polytunnel soil from last year's crop... which I soon pulled out.

Any advice about how I can avoid this happening in future years would be welcome. I've always had the polytunnel to fall back on when blight strikes the outdoor ones, but now this has happened, I wonder if my days of growing tomatoes are under threat!

Blight seems to be spread in 3 ways - wind, water and by overwintering in infected plant material, particularly potatoes left in the ground. I think if the spores are in your area and your polytunnel entrance happens to face the wind direction, your crops in there are in danger. This seems much more likely than the water from the well being the source of the infection, although overhead watering probably helped it spread. It is possible that it came in on your hands, if they were damp and you had been handling diseased plants. The disease takes a few days to become noticable after infection, so you may not have realized the plants you had been handling were infected.

The good news is that blight does not survive well away from solanaceous plant material, so if you remove all traces of tomatoes and potatoes from your tunnel once you have salvaged any crops you can, you should find that it has gone by next year. I have planted tomatoes in soil which grew tomatoes the previous year which got blight (my tomato growing areas are limited because very little of the garden is sunny) and I find that they do get blight, but no earlier than everyone else's. Last year that was October, whereas the previous wet summer saw the lot die by the end of August.

[Martin H]

I'm a bit worried about my potatoes "Charlotte". This is they today:



It seems to early in the season for them to go over naturally.

For now I've gone down the rows and picked off all the discoloured leaves, hopefully this will slow down the spread.

[Bigmallly]

I'm a bit worried about my potatoes "Charlotte". This is they today:

[ATTACH=CONFIG]47093[/ATTACH]

It seems to early in the season for them to go over naturally.

For now I've gone down the rows and picked off all the discoloured leaves, hopefully this will slow down the spread.

My 1st impression is that the soil looks very dry so maybe a good soak will help, otherwise they look fine to me so maybe are ready to lift soon.

[Martin H]

My 1st impression is that the soil looks very dry so maybe a good soak will help, otherwise they look fine to me so maybe are ready to lift soon.

I gave them a good soaking three days ago, so the soil is still moist underneath. Still, it has been very hot, so hopefully you are right.

[Martin H]

Well, on the encouraging side, Monty Don was lifting his Charlotte potatoes on GW last night, so maybe they are indeed ready.

But on the discouraging side, I see today that there's quite a lot of yellow leaves on my maincrop Cara. Here's a picture of the worst bit. Gurgling images of sick potatoes makes me think this is probably Early Blight. Anyone agree? If so, it could be worse... I'll carry on removing the diseased foliage and see what happens.

[roitelet]

My Charlottes planted on April 13 have succumbed to blight so chopped all the tops off and started to lift them as needed. They are fine and had I been able to leave them would have been a huge crop. However what I have is not to be sneezed at!

[Bill HH]

Black spots are not automatically blight. Blight spots are quite large and at first the area within the spot goes limp and purplish, you also get brown patches on the stems. If you have it is very rapid. I thought I had it but wasn't sure because it wasn't like the real blight I had last year, just small spots. Well its a month on and they are still growing. I think a lot of potatoes are dug up prematurely. But I can understand why.

[BertieFox]

This year's blight seems to be particularly virulent, in my experience. As I've already said, we have it inside the polytunnel as well as outside, and I have never seen both the fruit and the stems affected so quickly, almost before you notice the blotches and mould on the leaves. I've been removing every sign of infection from the tomatoes in the tunnel the moment I notice it and carefully disposing of the infected leaves, but it is depressing how the stems are blackening on some plants and the small fruit on even cherry types are going brown before they ripen.

Off topic slightly, did anybody else notice how Monty Don's potato harvest seemed to consist of a lot of worryingly green potatoes? He did mention finding one green potato but then went on putting more green ones into his 'harvest' basket. Inadequately earthed up I guess, and not a good example.