Filtrust [Cronartium ribicola]
Appearance / Visual damage
Small yellow to brown rust pustules, light on the leaf surface spots appear on the under side of leaves . In the summer, small brown columns rise in the leaf base (teliospores ).
Especially on black currant.
The symptoms show up in July.
White pine and stone pine are the fungus as an intermediate host.
The currant bushes are damaged by early leaf shedding and thereby prevent bud formation for next year.
Prevention / Control
No cultivation of currants in the vicinity of white pine. Sprays from beginning of infestation from post-harvest treatment, treatment being thorough from the leaf base