Elytroderma Disease Reduces Growth And Vigor Increases Mortality Of Jeffrey Pines At Lake Tahoe Basin California PDF Download

Little is known about Elytrodema disease (Elytroderma deformans [Weir] Darker) in seedlings or very young trees. Of 100, 2-0 Jeffrey pine (Pinu jeffreyi Grev. & Balf.) seedlings planted in the Taylor Creek area of South Lake Tahoe, about half survived from 1973 to 1987. During this period about two thirds of the surviving seedlings became infected with Elytroderma disease. Of the trees that died, only three were infected with the disease, and none was infected before 1981-82. Earliest infection of surviving seedlings was in 1976, with 1980-81 the only interval without infection. More than half of the infected trees were infected in the terminal shoot, indicating future impact on survival and height growth. No significant growth effects were measured between infected and noninfected trees in this study, however. On sites with high disease hazard at Lake Tahoe, avoid planting Jeffrey pines. Regenerate with resistant conifer species.