Phragmidium violaceum facts for kids
Quick facts for kids Phragmidium violaceum |
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| Blackberry plants infected with rust fungus, a biological control agent for blackberry. The newly released strains of the European blackberry rust fungus (Phragmidium violaceum) are highly host-specific for weedy blackberries. | |
| Scientific classification | |
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Phragmidium
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violaceum
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Phragmidium violaceum is a plant pathogen native to Europe, Africa, and the Middle East. It primarily infects Rubus species.
It has been used in the biological control of invasive blackberry species in Chile, Australia, and New Zealand. In 2005, it was discovered growing on Himalayan blackberry plants in Oregon. This accidental introduction does not appear to be infecting native vegetation, so it offers hope for reducing the impact of invasive blackberries in the Pacific Northwest.
Symptoms
The foliar symptoms that can be found include purple leaf spots along with yellow and tan centers. These can be found on the upper surface of the leaf and can resemble Septoria leaf spot. On the lower surface of the leaf yellow to orange pustules will be surrounded by a purple tinge. These can resemble cane and leaf rust. The leaves that are severely infected can start to dehydrate as well as start to curl. The leaves that are older and closer to the cane will get infected first and can die as well. The flowers and the fruits that are infected may fail to ripen. Stem infections as well as the continuous defoliation may cause the dieback of the canes. During the summer and fall the infected leaves can start to develop black pustules otherwise known as telia among the uredinia.
