Is this potato blight? (photos)

This is my first year growing potatoes, and we were careful to choose blight resistant ones (we planted 5 varieties, only one type is looking like this right now). Is it blight? Or what?
http://picasaweb.google.com/RachelRDutton/PotatoBlight#

I don’t think so, but I’m hardly a potato expert–this is only my third year as a wannabe potato farmer.

Right now, some of my (earlier) potatoes* are starting to look like that–beacuse the tops are starting to die back, which signals that it’s time to harvest! The later potato** plants, on the other hand, are still lush and green. Have yours already flowered?

(Obviously, YMMV: I live in central Kentucky and planted my potatoes on Good Friday.)

*Purple majesty and Corolla
**Purple peruvian (fingerling)

They’re currently flowering.

We’ve got planted Red Thumb, All Blue, Chieftan, Purple Viking and Yellow Fin. The Yellow Fin are the only ones looking like this right now.

  1. It could just be the potato plants dying off. They turn yellow and then brown as the crop matures.

  2. The bottom leaves turn yellow sometimes just because they get no light from the upper leaf canopy being so thick.

Ok, good…I was really excited about my potatoes, and did not want them all blighty.