The American elm was once dominant on the landscape, an iconic symbol of the nation’s landscape, but has unfortunately succumbed to a fungal disease introduced from Europe in the 1900s. The graceful, large elm trees widely planted in the suburban landscape for its shade, tolerance of poor soil conditions and fast growth. However, in the…
Oak wilt is a tree disease affecting oak trees caused by the fungus Ceratocystic fagacearum. The disease has been found in 21 states causing the most damage in the midwest. It was first found in Wisconsin in 1944 where localized pockets of mortality were found; nearly half the oaks an area of less than…
Officials with the Idaho Department of Lands (IDL) are puzzled over a seemingly new disease affecting ponderosa pines (Pinus ponderosa) in the region. They are discouraging culling trees with discolored needles until they can determine the underlying cause of the disease; this may mean waiting until June when the ponderosa pines produce new needles. According…
A common disease among eastern hard pines is eastern gall rust. In the U.S. the range of this disease includes Minnesota eastward to the New England states and south to the states bordering the Gulf of Mexico. Host trees include Scotch, Austrian, Jack, Pitch, Shortleaf and Loblolly pines, each within their respective range. Red, black…
Oak wilt is a tree disease affecting oak trees caused by the fungus Ceratocystic fagacearum. The disease has been found in 21 states causing the most damage in the midwest. It was first found in Wisconsin in 1944 where localized pockets of mortality were found; nearly half the oaks an area of less than…
Eastern spruce dwarf mistletoe, Arceuthobium pusillum, is a flowering plant which parasitizes black spruce, Picea mariana, and is the causal agent of its most serious disease. This parasite enjoys a broad range, thriving throughout the southern Canadian provinces, from Minnesota east to Maine and south to Pennsylvania. However, it is rarely found in New Jersey,…
Apple Proliferation Phytoplasma (APP) is a bacterial disease affecting mostly apples although pear trees with proliferation symptoms have been identified, but it has not been positively confirmed that they are suffering from APP. Apple cultivars seem to vary in terms of the degree of their reaction to the disease, Belle de Boskoop, Gravenstein, Starking, Golden Delicious and…
