Le principali malattie del noce da frutto: aspetti epidemiologici e tecniche di controllo

Well-known bacterial and fungal diseases affecting walnut trees represent a limiting factor in intensively cultivated areas. Nowadays, the most important bacterial and fungal diseases are: the bacterial blight, caused by Xanthomonas arboricola pv juglandis, and the anthracnose, caused by the ascomycete Marssonina juglandis (teleomorph: Gnomonia leptostyla). Other well-known diseases, although of minor impact, are the shallow bark necrosis caused by the Gram-negative rod Brenneria nigrifluens, the Armillaria root rot, caused by the basidiomycete Armillaria mellea and the crown and root rot, caused by a few oomycetes belonging to the genus Phytophthora. Two more diseases appear to be a possible future threat in walnut production: the blackline disease, caused by the Cherry Leaf Roll Virus (CLRV) and the thousand cankers disease, caused by Geosmithia morbida, a fungus that is disseminated by the walnut twig beetle, Pityophthorus juglandis.