Blackcurrant Powdery Mildew
American Gooseberry Mildew (Sphaerotheca mors-uvae) is the most common and economically damaging disease to affect both Blackcurrant and Gooseberry bushes.
The disease is first seen from May onwards as white fungal threads covering the small shoots. The conidial spores spread to the leaves at the shoot tips causing distortion and preventing development of the growing shoot.
Later in the season the infected leaves fall to the ground which act as the major infection point for the following spring.