Apple scab is a fungal disease that commonly affects trees in the rose family including crab apple, pear and apple trees. Leaves infected with Apple scab often turn spotty, yellow and drop prematurely. Trees are sometimes totally defoliated by mid-summer. Apple scab infections seem to be worse during wet, rainy springtime weather.
Tree Problem Category: Common Diseases
Rhizospaera Needle Cast
Rhizospaera Needle Cast is a fungal disease most commonly seen in Spruce. Other conifers such as pines and firs can also get the disease. Infection usually starts on the lower branches of the tree and progresses upward. After infection, needles turn yellow late in the summer. During the following winter or early spring the needles then turn anywhere from brown to a brownish purple color before beginning to drop.
Cytospera Canker is a slow moving fungal disease commonly seen on older Spruce trees among other conifers. Cankers form on the branches and trunks. Needles turn brown and drop, usually starting at the ends of branches, working inward. Often the disease starts on the lower branches and progresses upward, killing branches on one side.
Root Rot A variety of serious fungal pathogens that primarily attacks stressed trees. Symptoms include mushrooming, yellowing or stunted leaves, dieback of crown and overall decline. Infection can develop in one tree or infect multiple trees through root graphs.
Pine Wilt is a fungal disease that affects all pines, with the exception of the white pine. The fungus enters the tree when it is attacked by the Sawyer Beetle who is a carrier of a nematode. The nematode is the actual host of the fungal disease, not the beetle. Pines infected with Pine Wilt will suddenly brown up and die in a short amount of time.
Fireblight is a common bacterial infection seen in trees in the Rose family, with the ornamental pear the most commonly affected. Leaves and stems appear to be blackened or scorched at the ends of branches, hence the name fireblight.
Oak wilt is a fatal disease among the oak species, with Red Oaks being the most commonly and acutely affected. The symptoms, which usually appear in mid-summer, are sudden leaf wilting, browning and premature leaf drop. Leaves will often turn a bronze color before dropping.
Bacterial Leaf Scorch
Bacterial Leaf Scorch is a disease that appears on a variety of deciduous trees including oaks, maples, sweet gum, and mulberry trees. Once infected with the bacterial infection trees will develop scorch symptoms in the summer months and dieback slowly over the course of ten years.
Verticillium Wilt is a soil borne fungal disease that affects hundreds of different kinds of plant species. Many trees are susceptible to Verticillium Wilt with Maples, Ash, and Red Buds being more commonly affected. Sudden wilting of branches or sections of trees with staining of the sapwood are symptoms of Verticillium wilt.
Dutch elm disease
Dutch elm disease is a fungal disease that is spread by elm beetles and through root graphs from surrounding infected trees. Elms infected with Dutch elm disease show symptoms that include wilting, yellow, curling leaves in the outer canopy.