Some of the leaves of my potato plants are turning yellow, in fact one or two have shrivelled up and died. I dont think it’s blight because I’ve been spraying them with dithane regularly. Could it just be bad seed? Thanks M
One is potato cyst eelworm which is often a problem when potatoes have been grown in the same soil for years. This tends to occur in broad patches and potato growing can be impossible.
Another is black leg, which kill a few plants here and there usually. The affected plants should be dug up and discarded.