My neighbour at the allotment has blight on his potatoes. He has rows and rows of them so I hope he does something about it quick as it spreads like mad. Blight was the cause of the Irish potato famine and is an airborne infection that thrives in warm humid conditions so the recent weather has been perfect for it. One or two of my plants are showing tell tale brown spots on the leaves and other people have also noticed it on theirs. I’ll keep a close eye on them because it develops very quickly in the matter of a few days. If the spots multiply and spread to the stems and the leaves begin to yellow it’s important to act quickly. Cut the plants down to a couple of inches. Don’t compost them, bag them up and take them to the tip or leave them out for the green rubbish collection if you have one. Leave the potatoes in the ground for three weeks to allow the skins to harden slightly and any spores on the surface to wash away. You should’ve able to store them but check regularly for signs of rot.
