Chronic wood infections caused by Cytospora species can be devastating to fruit trees. The Cytospora canker can be produced by many species of the genus Cytospora. Cytospora fungi commonly found in orchards are Cytospora cincta and Cytospora leucostoma. From a morphological point of view, the two species are difficult to differentiate. Cytospora species mainly affect branches, but can cause destructive infections in trunks and large branches, severely limiting the longevity and productivity of orchards. This cancer is considered serious in declining or poorly maintained orchards, where the trees are no longer vigorous. Due to infections, the trees can dry out and the economic losses are major. It can be found frequently in the improper managed orchards or old orchards were is producing important loses by the drying of the branches and even the death of the trees following the infection through lesions produced by hailstone, frost, insects and tools. Usually the most sensitive trees are the weakened ones. In the last years the fungi from the genus Cytospora become more frequent in the cherry orchards from Romania. It is problematic the fact that frequently the infected trees are young. This research is a case study based on the infection with a fungus from Cytospora genus from a cherry orchard from western Romania. The main purpose of the paper was to correctly identify the above mentioned orchard pathogen by laboratory analyses (macroscopic and microscopic). Tissue samples from branches and sprouts were placed on the culture medium for the observation of the mycelia. The prepared samples were incubated at a temperature of 24 oC, for 5 days. The results obtained show that the fungus responsible for the cherry tree death belongs to the genus Cytospora. The form and colour of the pycnidia from beneath the bark is specific to the species Cytospora leucostoma, this species being reported by other researchers too as present in the orchards from Romania. The perfect form of the fungus (Valsa) wasn’t observed.

Cytospora leucostoma, Cytospora canker, pycnidia, cherry, pycniospores, perithecium, lesions

biology

Presentation: poster