Hop Powdery Mildew
Hop Powdery mildew normally appears on two distinct stages.
The first stage occurs in around May when small powdery colonies appear on the young hop leaves and shoots.
A more serious development is when the female flower or burr becomes infected as this normally leads to distortion or death.
In late summer the second stage appears especially during warm and humid weather. when small reddish patches are seen on the leaves and cones with tiny pinhead black spots. If not controlled this more aggressive stage will over-winter on the debris on the hop yard floor to begin the infection cycle again the following year.