Blight???!!!

[SarzWix]

There's a whole big thread at the top of the Vegging board, all about blight, with pictures and lots of links.

Tattieman sells a blight testing kit from his website.

TimH, they certainly look a bit suspect. Cut the affected leaves off, and look out for any more splotches appearing. It may be scorch from water droplets on the foliage getting into full sun, then they'll be dry and crispy. If it's blight they'll be a bit soggy and may have white spores forming on the underside.
Cut off any affected foliage as soon as you see it, and if it gets overwhelming chop it all off and either burn it or bag it and put it in the household rubbish.

[tattieman]

TimH they do look a bit suspect. I got a blight warning sent to me today. I have seen this happen to plants that have been bitten by insects or have water burn. The leaves that seem to be affected are at the bottom and it could be that maybe they are not getting enough light down there. Best plan which goes for everyone. Remove the affected stem so that the rest of the crop can't be affected and spray with Dithane 945 to try and stop things spreading.

[Flummery]

Does everyone spray their potatoes for blight? First year growing them

I never do. But I only grow earlies. You can get away with it as the potatoes are usually ready to harvest before there's a problem.

[zazen999]

Does everyone spray their potatoes for blight? First year growing them

My theory is that, if I don't and lose a fair amount of them, then I will have to buy potatoes from the shop which will have been sprayed to stop them getting blight.

So, I spray. It's the only non-organic thing I do. But I have to be realistic and that means trying to actually get a crop of spuds from the crop and not losing too many.