rust of currant. disease on black currant leaves caused by a fungus cronartium ribicola

leaf green plant flower nature tree produce shrub insect branch grass herb invertebrate wildflower food petal rust currant disease black leaves caused fungus cronartium ribicola macro blister agriculture yellowing dying attack yellow foliage growth environment season color garden background pinus strobus ribes nigrum damage fungal infection pine bush protection cure summer host protect natural ill rusty diseases orange symptoms closeup spores spots infect underside currant ribicola