![]() Infections are frequently reported in the southern states, but may also be observed in the northeastern and midwestern states.īrown spot needle blight frequently infects longleaf pine, ponderosa pine, and Scots pine. Severe infections may culminate in tree mortality.īrown spot needle blight occurs throughout the United States. Successive defoliations of host trees can inhibit growth, and reduce tree vigor. Infected needles are often shed prematurely. It also promotes the browning of infected needles. Brown spot needle blight induces the formation of needle spots. The damage produced by brown spot needle blight resembles that of the Dothistroma and Lophodermium needle blight diseases. The disease is caused by the pathogen, Mycosphaerella dearnessii. Cenangium dieback also occurs frequently on Scots pine, as does physiological needle blight.Brown spot needle blight is a fungal disease of pine trees. 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).Cyclaneusma needle cast ( Cyclaneusma minus).Black snow mould ( Herpotrichia pinetorum).Scleroderris dieback / Brunchorstia dieback ( Gremeniella abietina).Cenangium dieback ( Cenangium ferruginosum).Diplodia pine tip/shoot blight ( Diplodia sapinea).Red band needle blight ( Dothistroma spp.).Brown spot needle blight ( Lecanosticta acicola).Detailed descriptions of these needle and shoot diseases on Scots pines can be found in the original publication:
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