New canker disease of pear in Italy: addition of Valsa ceratosperma to the EPPO Alert List
The NPPO of Italy informed the EPPO Secretariat of the presence of a new canker disease of pear in Emilia-Romagna caused by Valsa ceratosperma (Ascomycetes: Diaporthales). In 2001, this new canker disease was observed on a limited number of old pear trees (30-40 years old), in 3 orchards in Emilia-Romagna (1 in the province of Modena, 2 in Ferrara). Laboratory analysis revealed the presence of Valsa ceratosperma [anamorph Cytospora vitis (=C. sacculus)]. In 2002 and 2003, the disease was observed on a larger number of trees in the provinces of Modena, Ferrara and Bologna. V. ceratosperma was not only found on old trees, but also on young productive trees (from 8 years-old). In some orchards, cankers were observed on 70% of the trees. In these orchards as heavy pruning was needed to contain the disease, crop losses were observed. Surveys have been conducted in nurseries on certified and CAC multiplication material, but so far V. ceratosperma has not been found. According to the literature, this is the first report of V. ceratosperma causing canker disease on pear in Italy and in Europe. Finally, the EPPO Panel on Phytosanitary Measures considered that this fungus should be added to the EPPO Alert List. The situation of V. ceratosperma in Italy can be described as follows: Present, found in Emilia-Romagna (provinces of Bologna, Ferrara and Modena) at low prevalence and subject to containment measures.
Valsa ceratosperma (a new canker disease of pear)
Why: The presence of a new canker disease of pear caused be Valsa ceratosperma was reported by Italy, and the EPPO Panel on Phytosanitary Measures considered that this fungus should be added to the EPPO Alert List.
Where:
EPPO region: Italy (Emilia-Romagna). In Italy containment measures are taken to prevent any further spread.
Asia: China, Japan and Korea
Note: The IMI description of V. ceratosperma (no. 1366, 1998) gives a much broader distribution. However, the disease it cause on pear, apple and quince has only been observed in the Asian countries mentioned above and now in Italy.
On which plants: Cydonia oblonga, Malus domestica, Pyrus communis. In Asia, Valsa canker is mainly reported on apple, and occasionally on pear and quince. In Italy, it was only found on pear. (cv. Abate Fétel was the most affected, but other cultivars (i.e. William, Decana, Kaiser, Passecrassane, Morettini, General Leclerc) were also found susceptible).
Damage: The fungus causes elongated cankers on twigs, branches and trunks. Symptoms can easily be confused with other pathogens such as: Nectria galligena, Sphaeropsis malorum, Phomopsis mali and Erwinia amylovora. When cankers develop, they can girdle twigs, branches and even trunks, which then lead to desiccation and death of the distal part. V. ceratosperma overwinters in infected wood and plant debris, and most new lesions appear in spring. The affected bark is swollen, watersoaked, and in February small dark pycnidia can be observed. In spring, under humid conditions, pycnidia release spores which are responsible for new infection. The fungus penetrate through natural bark crevices and wounds (due to adverse climatic conditions or pruning). Ascospores are also formed in autumn/winter but it seems that they only play a secondary role in disease spread. In the literature, it is mentioned that on apple, the disease may remain latent for 1 to 3 years.
Dissemination: Within orchards, disease spread is ensured by the production of pycnidiospores in spring and to a lesser extent by ascospores in autumn/winter. Over long distances, trade of plants and eventually of wood can ensure dispersal of V. ceratosperma.
Pathway: Plants for planting, wood of Cydonia, Malus and Pyrus from countries where V. ceratosperma occurs.
Possible risks: Fruit crops such as pear, apple and quince are important for the EPPO region. Control of canker diseases is usually difficult in practice. Mechanical removal of cankers is a possibility, and data is currently lacking on chemical products which may be effective against V. ceratosperma. In Italy, high incidence in affected orchards and crop losses are already observed. Therefore, any further spread of this disease should be avoided.
EPPO RS 2004/052
Panel review date - Entry date 2004-04
Sources
Agricoltura, February 2003. Il “cancro da Valsa”, nuova malattia del pero. Carla Montuschi, Servizio Fitosanitario, Regione Emilia-Romagna. http://www.regione.emilia-romagna.it/agricoltura/rivista/2003/02/ra030266.pdf
Servizio Fitosanitario Emilia-Romagna. Un nuovo agente di cancri rameali su pero Il “Cancro da Valsa”, malattia accertata per la prima volta nella nostra regione nel 2001, è in corso di studio da parte del Servizio fitosanitario regionale. di Carla Montuschi, Servizio Fitosanitario, Regione Emilia-Romagna http://www.agrimodena.it/pere/cancrodavalsa.html
Cancro da Valsa - Valsa ceratosperma (Tode:Fr. ) Maire (f. con. Cytospora vitis Mont.). http://www.regione.emilia-romagna.it/fitosanitar/avversita/primo_piano/valsa/valsa.htm
IMI (1998) Descriptions of fungi and bacteria no.1366. Valsa ceratosperma. CABI, Wallingford, UK.
NPPO of Italy, 2004-03.