Blight

[NattyEm]

 :'( Thats all the spuds now.  Humph.  Doesn't help that other lottie holders seem to do nothing about their spuds even after people point out blight to them.  We've taken off all the foliage in a hope that the tubers will be alright.  Have found a couple of tubers where its spread though.  So heres the question - do we have to dig up all the spuds and sort through them to pick out any affected, or are they OK to leave in and remove the bad ones as we go?

If we do have to dig them all, whats the best way to store them?  A few we have had up of the main crop aren't too small. Phew!

[NattyEm]

[jennym]

Wow - you have blight already? We don't normally get it here until mid August. What I normally do is cut the foliage off. then wait a couple of weeks until digging any potatoes up. I then take them home, wash them and let them dry off. Don't usually lose any that way.

[djbrenton]

According to http://www.potatocrop.com/blight/ Dorset has had  few Smith periods this year. So far in Nottingham we've only had one.

[Robert_Brenchley]

The only time I've had it was in June. That was the first year I had the allotment; between blight and being flooded four times, I could hardly have had a worse year.

[john_miller]

The only time I've had it was in June.

That sounds more like early blight, Alternaria solani, than late blight.

[Mrs Ava]

Is this blight on my taters?

[jennym]

The blight I get in August doesn't look like that. Maybe, as john_miller says it's early blight but I must admit I'd not heard of early blight before.

[Robert_Brenchley]

Whatever it was it totally wiped out both my spuds and my tomatoes. If I was dependent on my spuds like the Irish poor in the 1840's I'd have been finished; I've read accounts of people dropping dead in the streets and I can understand why it happened. Is there a page somewhere on the epidemiology (rather than treatment) of the disease?

[NattyEm]

well we've been lucky enough to see early blight and blight.  Our first earlies were affected, but taking the foliage off of them was fine, it hadn't gone down into the tubers - but the main crop on inspection it has gone down into a couple of the tubers.  So still not sure if we should take the whole crop up, or leave the usual 3 weeks or so then start moving them.

[jennym]

Try websites:
www.ext.nodak.edu/extpubs/plantsci/hortcrop/pp756w.htm
and
www.ipm.ucdavis.edu/PMG/selectnewpest.potatoes.html

these are USA sites so beware, any chemicals listed may not be legal in UK. But the images/info is really good.

[fbgrifter]

"blight is spread by rain splash and air currents, and they may wash down to the tubers in rainfall or irrigation water.  the fungus only becomes active when there are 2 consecutive 24-hour periods with a min temp. of 10 degrees and a relative humidity of 89% or more for 11 hours in each of the 24-hour periods. 

control:

reduce risk by earthing up deeply.  if haulms show symptoms of infection, remove them as soon as they begin to die down.
to prevent infection spray foliage with copper based fungicide such as bordeaux mix or copper oxychloride, or with mancozeb."   - RHS

[northener]

Don't know EJ but my tatie foliage looks the same. 90% of the taties are ok other 10 % are squishy i'd put this down to wireworm.

[Robert_Brenchley]

Wireworm leaves potatoes solid but full of little holes. If they're goind squishy that's some form of rot, I always get a few like that myself.

[tim]

Or this??

It doesn't look like blight & it doesn't seem to be spreading - DV!

[Kepouros]

tim, I`ve got a touch of that on my potato foliage as well.  I suspect that it`s purely physiological and due to the dust dry soil that they are trying to grow in causing some sort of mineral deficiency.  If the soil is about neutral pH some of the minerals need a reasonable amount of moisture to become soluble, and that`s been sadly lacking recently.

[tim]

Here's hoping!!