P. pittieriana is a microcyclic (short cycle) rust that produces only teliospores and basidiospores.
There are no records of transported contaminated crop produce causing spread of P. pittieriana. The only risk of spread is by the transport of infected plants or plant material, which is usually prohibited. Field-grown potatoes [ Solanum spp.] from highland areas in countries where this disease is known should not enter international trade. There is no need for detection and inspection procedures if appropriate transport restrictions are observed.
Related invasive species
- Puccinia pittieriana
Related Farm Practice
- Defoliation
P. pittieriana is a microcyclic rust fungus occurring on potato [ Solanum tuberosum ], tomato [ Solanum lycopersicum ] and wild species of Solanum in South and Central America and is an EPPO A1 quarantine organism for Europe (EPPO, 1988). Probably capable of causing disease on potatoes in cool, moist regions of the temperate and tropical zones, this fungus can be transported in fresh or dried plant material or crop debris in soil. As the basidiospores are short-lived and not produced in large numbers, the fungus is not spread far by natural agents such as the wind.
Lesions begin as minute, round, greenish-white spots that grow up to 3-4 mm diameter on the underside of leaves. Some lesions become elongated with their longer axes reaching 8 mm. They later become cream, with reddish centres that turn tomato-red and finally rusty-red to coffee-brown. The lesions protrude by 1-3 mm, with corresponding depressions on the upper leaf surface, and may be surrounded by chlorotic or necrotic halos. Defoliation results when hundreds of lesions form on a leaf. Elongated or irregular lesions occur on petioles and stems;fruits and flowers are also affected (French, 2001a).
Field observations were made on cultivated tomato [ Solanum lycopersicum ], cultivated potatoes (Solanum tuberosum subsp. andigenum and subsp. tuberosum), and the wild potato, Solanum demissum. All other records of susceptibility listed are the results of greenhouse tests (Reddick, 1932;Buritica et al., 1968).
P. pittieriana affects the following cultivated and wild potato species in greenhouse tests:
- Cultivated potato: Solanum ajanhuiri, Solanum curtilobum, Solanum juzepczukii, Solanum phureja, S. tuberosum subsp. andigenum and S. tuberosum subsp. tuberosum.
- Wild potato species: Solanum antipoviczii [ Solanum stoloniferum ], Solanum cardiophyllum, Solanum commersonii, S. demissum, Solanum ehrenbergii, Solanum gibberulosum, Solanum famatinae [ Solanum spegazzinii ], Solanum malinchense [ Solanum stoloniferum ], Solanum oplocense, Solanum parodii [ Solanum chacoense ], Solanum schickii, Solanum simplicifolium [ Solanum microdontum ], Solanum stoloniferum and Solanum verrucosum (Buritica et al., 1968).
- Other species of Solanum affected are Solanum caripense and Solanum nigrum in Colombia (Buritica et al., 1968).