Potato rust?

I mentioned potato rust in a previous blog but didn't show you clearly what I meant.  I am not sure what it is but looks more like rust than blight.  It had affected the leaves of the row of Charlottes that I have just finished harvesting but the potatoes were perfect.  It is also infecting the leaves of the middle row of Estima.  This photo is of them.  Estima will have had the markings longer when I come to harvest them so it will be interesting to see if it has any effect on the tubers.

My third row and my all time favourite spud, International Kidney, is utterly unblemished.  I can't recommend these enough - they have been successful every year, including a blight year.  No wonder they are grown commercially - these are Jersey Royals but the name can't be used outside Jersey! They must be the best new potato bar none, but the surprise is that  they go on and on.  The end of my harvest will yield many good size potatoes often weighing around  half a pound each (225 g) and in perfect nick.