concolor), can suffer severe damage as well. True fir ( Abies), especially white fir ( A. rubens) are more resistant to the disease. orientalis) are the most severely affected, while Norway spruce ( P. HostsĬolorado blue spruce ( Picea pungens), white spruce ( P. Of these seven Rhizosphaera species, the majority of spruce are infected by one particular species. Research from the UMass Plant Diagnostic Laboratory has identified at least seven phylogenetic species in the northeast from six host genera ( Picea, Abies, Tsuga, Pinus, Pseudotsuga and Cedrus). Cenangium dieback also occurs frequently on Scots pine, as does physiological needle blight.Rhizosphaera needle cast is caused by several species in genus Rhizosphaera, and while the ecology and pathogenicity of these species are poorly understood, the disease is most often attributed to R. On the most common Swiss pine species, the Scots pine, red band needle blight is the most frequently recorded cause of damage, closely followed by Diplodia shoot dieback (Fig. All other pathogens described here are responsible for only a small proportion of the damage reported on black pine. Red band needle blight is the second most common disease affecting this species, but occurs much less frequently. 3, black pine) in black pine, damage caused by Diplodia shoot dieback ( D. There are clear differences between black pine and the other pine species (Fig. The third most common condition observed was physiological needle blight. ![]() On mountain pine, these two imported diseases, the redband needle blight and brown spot needle blight, together account for more than 75 % of the observed infestations of mountain pine. Of all the pine species described here, mountain pine is most affected by brown spot needle blight (Fig. Brown spot needle blight ( Lecanosticta acicola) has not yet been found on Swiss stone pine. It is thus more likely to be detected in gardens than in the forest. As stone pines have relatively thin needles, symptoms of red band needle blight are sometimes more difficult to see. Damage of Swiss stone pine caused by the red band needle blight (Dothistroma spp.) originates in urban areas. Physiological needle blight (PNB) in principle thus affects all pines. The latter is not surprising, since all needles die after a few years. Also common were snow blight ( Phacidium infestans) and physiological needle blight (natural ageing of the needles, not a fungal disease). ferruginosum) and Scleroderris shoot dieback, also known as Scleroderris canker ( Gremmeniella abietina), were the diseases most frequently found on needles and shoots of the stone pine (Fig. Although it is not a disease, the phenomenon is listed here for the sake of completeness.Ĭenangium shoot dieback ( C. Accordingly, it is mainly older needle generations that are affected. Physiological needle blight is a natural process resulting from needle ageing, and one that every needle goes through. Pine needle rust ( Coleosporium tussilaginis).Sydowia dieback of pine ( Sydowia polyspora).Sydowia dieback of pine ( Lophodermella sulcigena). ![]()
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