Phragmidium violaceum

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. ==Disease cycle==

The pathogen is a macrocyclic, autoecious rust fungus, and produces five different spore states that represent the asexual and sexual components of the life cycle. Dikaryotic urediniospores are released during the summer as well as the spring while teliospores represent the overwintering stage. When the sexual outcrossing occurs the dikaryotic aeciospores and urediniospores are initiated. The teliospores in the spring will then undergo meiosis in order to produce haploid basidiospores. This follows the insect-mediated transfer of spermatia from the spermogonia of the different types of mating to the receptive hyphae. The spores are spread very easily and can be spread by wind. ==Management==

Cultural tactics along with dormant season lime sulfur can help to reduce the initial inoculums source. The chemical tactics function to protect the healthy younger plant tissues. The amount of inoculums released is small when compared with the well-adapted pathogen that exists in the population ==References==