This is why it is a good idea to not sprinkle irrigate. Lower leaves are also often removed as they create a camp area around the basal spikes ideal for spreading the disease. Downy mildew can be controlled by spraying a copper fungicide such a Kocide 101, but repeated applications may be necessary as rain will wash off the fungicide. Systemic fungicides such a Ridomil and Aliette provide longer protection but may not be available to home gardeners. Hopefully this disease is not a problem in your area, so don't worry about it unless the spikes appear.
Powdery mildew is the oldest of the fungal diseases affecting hops.
It caused great damage in the USA when hops were grown on the east coast and was one of the problems that forced the hop industry west where powdery mildew does not occur in commercial hop yards. The disease is characterized by white fuzzy mold growing on both sides of the leaves. If the disease proves to be persistent, it can be controlled with sulfur based fungicides. This pest is a problem in all hop growing districts of the Northern Hemisphere except some areas in China. If uncontrolled, this insect is capable of completely destroying a crop.