We thought a week ago that our main crop might have blight. Blight is probably one of the worse diseases you can get and it can wipe out your whole crop. It was the cause of the Irish potato famine and so obviouly we were pretty concerned. I'd seen loads of pictures of the leaves curling at the end and going brown - and this is excatly what we had so hence the worry.
What is blight?
Blight is a fungus – Phytophthora infestans. It's triggered by warm wet conditions and August this year has been great for blight - warm and SO much rain. The first thing are brown patches on the leaves. The tubers can be affected as well and they'll just rot from the skin through the flesh.
What can you do to prevent it?
Well, not much really. It's killed by cold weather so cross your fingers for a few cold days! There are a few chemical treatments Bordeaux mixture which is organically approved but contains copper which probably isn't that good for you... and Diathane 945 which sounds horrid!
The best way to get round is it to choose a variety that is less affected by blight.
Thompsan & Morgan have a good list here.
What can you do to treat it?Again, not much! If it's just a few leaves that seem to be affected then you can remove those. Whatever you do, don't put them on your compost heap! The spores will love it in there. If possible burn. By pruning this may stop the spores from reaching the tubers (as long as they're well earthed up)
We duly followed instructions and took off any foilage that showed signs of browning. The plants actually look pretty healthy - albeit a little bald now! I'm now not sure that it is actually blight. I've read a few forums and I think we might be lucky...
Watch this space!
