Potatoe Blight

Hi, I have two bags of King Edward Potatoes which were planted on March 9th so been in for nearly 16 weeks. I went to tie them up this week and noticed that at the back and quite far down near the soil these yellow leaves and marks. Does anyone know if this Is Blight or just natural die off? I am not an expert and never seen blight before so unsure. They are planted in large potatoe bags bought from a garden centre and I have noticed that a few little ones are popping through the soil at the top so keep covering them up again. I ended up tipping on out to see how they were getting them on and was a bit disappointed as there wasn't very many and lots of tiny ones. I have also noticed brown marks on my parsnips leaves which are planted in the next bed to the potatoes, do they get blight too?
Thanks

 

Dont look like blight to me, and never heard of parsnip blight.

King Edwards are main crop, so wont be ready for a couple of months yet.

 

Ah that would explain it then :S I thought it was 20 weeks from planting but I am a newbe. Glad to hear it might not be blight, thanks