Criticità e tecniche di controllo delle principali avversità fitosanitarie

Bacterial blight, caused by Xanthomonas arboricola pv juglandis and anthracnose, caused by the ascomycete Marssonina juglandis (teleomorph: Gnomonia leptostyla) are considered the major diseases for walnut species. Other well-known diseases 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. Many insect pests may also damage the crop and the main ones are the codling moth (Cydia pomonella), the walnut husk fly (Rhagoletis completa) and aphids (Callaphis juglandis e Chromaphis juglandicola). Other insect pests, defined as minor threats are: the leopard moth (Zeuzera pyrina), the carpenter moth (Cossus cossus), scales and mites.