Is It Blight?

[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.

[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.

[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.

[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!

[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.

[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.

[Marb67]

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

[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.

[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.

[Marb67]

Only the odd leaf but mostly healthy foliage. Destroyed the picked off ones just in case. Just hope it isnt blight.

All first early crops[ATTACH=CONFIG]46769[/ATTACH]

So is this blight ? I found some more leaves today i have pulled off. All in containers and not soil.

[Penellype]

Ive had blight on tomatoes, which ruins the crop completely - once it strikes you can guarantee that any green tomatoes will rot rather than turn red. I've not had much of a problem with potatoes, possibly because I grow them in bags. The foliage flops over so the blight spores (if any) probably fall onto the path rather than onto the soil and potatoes. I also leave the potatoes in the bags until I need them, removing the dying foliage and moving the bags into the garage. Apparently if you get blight it is better to cut off the foliage and leave the potatoes buried until you need them rather than hurrying to get them out of the ground. If you have earthed them up there is a chance the spores will be washed away down the slopes whereas if you dig them straight away the spores get onto the tubers. That's the theory - I have not tested it myself.

[Rocketron]

June 17th 2014

On Sunday I harvested some potatoes and the plants were in great shape. Then we had a heavy thundery rain storm with a northerly wind, and today I noticed a whole load of the potatoes with the characteristic brown blisters.

I blame blight being blown in on the wind and rain from the UK! But wherever it came from, it is such a disappointment as it means we have to remove all the potato foliage and harvest whatever the plants have made so far.

Worse, a few of the tomatoes have already been affected, and stupidly, I planted a row of them just next to the potatoes.

I shall spray the tomatoes tomorrow with Bouille Bordelaise as a preventative and hope that the sunny weather will keep the blight at bay there, but it means soiling the fruit with all that horrible blue copper stuff!

How do people elsewhere cope with blight? Is it a problem in your area? I am almost at the point of giving up on growing potatoes in future as this happens every year. Otherwise I will have to copy the French locally and spray everything with Bordeaux mixture early on.

That's the only way I have found successful in East Sussex.

[Marb67]

Do i have blight

Only the odd leaf but mostly healthy foliage. Destroyed the picked off ones just in case. Just hope it isnt blight.

All first early crops

[BertieFox]

June 17th 2014

On Sunday I harvested some potatoes and the plants were in great shape. Then we had a heavy thundery rain storm with a northerly wind, and today I noticed a whole load of the potatoes with the characteristic brown blisters.

I blame blight being blown in on the wind and rain from the UK! But wherever it came from, it is such a disappointment as it means we have to remove all the potato foliage and harvest whatever the plants have made so far.

Worse, a few of the tomatoes have already been affected, and stupidly, I planted a row of them just next to the potatoes.

I shall spray the tomatoes tomorrow with Bouille Bordelaise as a preventative and hope that the sunny weather will keep the blight at bay there, but it means soiling the fruit with all that horrible blue copper stuff!

How do people elsewhere cope with blight? Is it a problem in your area? I am almost at the point of giving up on growing potatoes in future as this happens every year. Otherwise I will have to copy the French locally and spray everything with Bordeaux mixture early on.

[WPG]

As the blightwatch map doesn't cover Northern Ireland, just wanted to let other N Irelanders know that the Dept of Agriculture NI have a blight map at

DARD Blight-Net 2013 | Department of Agriculture and Rural Development

There's been several risk periods, but only one actual warning in early July. So far, touchwood and fingers crossed, everyones' spuds look fine on my allotment in County Down (last year the blight had spread by mid July).