Thousand Cankers Disease
Thousand cankers disease (Geosmithia morbida) is a newly recognized disease of black walnuts. It gets its name from the large numbers of small cankers on the branches and stems that eventually coalesce and result in necrosis of bark tissue. It is vectored by the walnut twig beetle (Pityophthorus juglandis).
Sudden Oak Death
Sudden oak death is caused by a water mold (Phytophthora ramorum) that threatens the vast oak forests of the eastern United States. The disease causes girdling cankers on the main stem and large branches which coalesce to eventually kill the entire tree. Sudden oak death (which is not very sudden) is responsible for killing millions of oaks in the western states.
Laurel wilt is a fungus (Raffaelea lauricola) that is vectored by the redbay ambrosia beetle (Xyleborus glabratus). It is spreads very quickly and kills plants from the Lauraeae family (redbay, sassafras, avocado) as well as a few other susceptible species. Symptoms are similar to those caused by drought.
Hypoxylon Canker (Hypoxylon spp.) is a secondary disease that affects trees that are already stressed by some other cause. Symptoms include delayed bud break, undersized leaves, wilted foliage and branch dieback. Signs include large spore-bearing mats visible after the bark has sloughed off.
Armillaria root rot is a general name for a group of diseases caused by fungi from the genus Armillaria. These are pathogens of roots and lower stems of both hardwoods and pines and are decomposers of wood. Signs include honey colored mushrooms at the base of the tree and black 'shoestring' rhizomorphs under the bark of infected trees.
Annosum Root Rot
Annosus root rot or Heterobasidion root disease is a serious disease in pine plantations that have recently been thinned. The fungus (Heterobasidion annosum) infects freshly cut stumps and spreads to living trees through root grafts which then makes those trees highly susceptible to wind-throw.
Fusiform rust (Cronartium quercum F. sp. Fusiforme) is a very common and potentially serious disease of slash and loblolly pine. The disease causes galls on stems which deforms trees, reduce growth, and weaken wood making trees more susceptible to breakage or bark beetle attack.
Pitch canker is caused by a fungus that creates a resin-soaked lesion in the inner bark and outer sapwood of southern pine species. Most often a nuisance, the disease can deform trees, suppress growth, and kill branches or occasionally entire trees. Contrary to popular belief, the pitch canker fungus is not carried or transmitted by insects; rather the fungus infects trees through wounds including but not limited to insect feeding sites.
Oak decline is a disease complex with many contributing stress agents and no single agent as a dominant role. It is a combination of biotic and abiotic stress agents such as drought, insect infestation, late frost, soil compaction, root damage, poor site, and mechanical injury.
Phytophthora Root Rot
Phytophthora root rot is a general name for a group of diseases cause by the fungi species Phytophthora. The pathogen attacks the roots of many trees and shrubs including azalea, rhododendron, dogwood, juniper, Fraser fir, white pine and others. Symptoms resemble those caused by nutrient deficiency, drought or decline.