Agree. There are sprays for roses but for food plant don't recommend it you know. Maybe not enough sun and too much standing water on the leaves. Where are the hop grower experts?

These hops get full sun all day.
I water them maybe once a week and I only water at the bottom of the plant.
I don't see any bug infestation.

Some of the hop cones have a browning of the leaves, but they just seem to be dry.

Powdery mildew is white - none of the leaves are white.

They are kind of a verigated yellow - maybe it's downy mildew?

Possibly iron deficiency? If the soil is highly alkaline, the Fe present may be bound up and not available to the plant... iron deficiency shows up as more of the variegated yellowing of the leaves...

That's a good ide, I'll take a ph reading.

Here is an idea. Why not take a cutting of that down to the local garden center/nursery or to the county extension office. Either place will have folks trained to know this kind of thing.

Wayne

Good suggestion Bug.... the should be more qualified than me!

I agree. Based on Wayne's comment I found this site which lhas a good description of issues.
http://www.ppath.cas.psu.edu/EXTENSION/PLANT_DISEASE/

Thanks Wayne.

Just stumbled across this..Possibly something similar?

http://www.freshops.com/hop-growing/hop-powdery-mildew