What's killing my hops?

Has anyone seen this before? I have sprayed insecticidal soap so I don't think it is bug related.
Thinking it is a deficiency of some sort but I have fertilized and given it cow manure and grass clippings for nitrogen. Is it lacking something else?

 

Did you spray it when the sun was shining bright, or mix your soap spray too strong? That'd be my guess, either one can cause damage like that.

 

Mixed per instructions and in the evening. It seems to be working its way up from the bottom.

 

Hmm dunno then, maybe over/under watering...

 

Looks like pretty typical lower leaf yellowing. Just some general stress, and the plant starts to kill off lower leaves that do not get much sun anyways. I wouldn't worry about it unless it starts to get much worse.