Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Main diseases of high quality timber broadleaves.

Abstract

In Italy, EU and national measures since the eighties have led to a considerable increase in the cultivation of high-value broadleaves such as walnut (Juglans regia and J. nigra) and cherry (Prunus avium) and to a less extent oak (Quercus sp.), ash (Fraxinus sp.), and alder (Alnus sp.). Studies have shown that the successful cultivation of these trees is often hampered by disease. Of particular importance in this context are attacks of anthracnoses by Gnomonia leptostyla and the disease known as black spots caused by Xanthomonas campestris pv. juglandis [X. arboricola pv. juglandis]; further cherry leaf spots by Cylindrosporium padi [Phloeosporella padi], Coryneum blight by Sporocadus carpophilus [Stigmina carpophila] on the cherry trees, Powdery mildew by Uncinula aceris [Sawadaea bicornis] on maple, by Microsphaera alphitoides on oak, and by Phyllactinia guttata on ash. Also very serious are root rots by Phytophthora spp. (often originating in the nursery) on walnut and cherry, and vascular wilts by Verticillium spp. on alder and cherry. Among less injurious diseases may be mentioned root rots from Armillaria and Rosellinia, branch canker caused by various agents, and sooty moulds. Diseases that merit particular mention are: on Juglans, white leaf spots by Microstroma juglandis, and branch necrosis by Botryosphaeria ribis; on Prunus, shoot blight by Monilinia laxa; on maple, spots from Cristulariella depraedans and Gloeosporium apocryptum and tar spots by Rhytisma acerinum; on Fraxinus, leaf blotch by Venturia fraxini and leaf spots by Mycosphaerella fraxinicola; on Quercus, anthracnoses by Apiognomonia quercina [A. errabunda]; on Alnus, rust by Melampsoridium alni and leaf spotting by Leptothyrium alneum.