COMMON PLANT DISEASES Disease fungi take their energy from the plants on which they live. They are responsible for a great deal of damage and are characterized by wilting, scabs, moldy coatings, rusts, blotches and rotted tissue. This page is designed to help identify some of the more common plant diseases and provides earth-friendly solutions for combatting them. Click on the links or pictures below to learn more. Anthracnose
Anthracnose Description: Generally found in the eastern part of the U.S., anthracnose infected plants develop dark lesions on stems, leaves or fruit. These lesions often become covered with pink spore masses. Dieback often occurs. Apple Scab Apple Scab Description: One of the most serious diseases of apple and ornamental crabapple. Disease development is favored by wet, cool weather that generally occurs in spring and early summer. Both leaves and fruit can be affected. Bacterial Canker Bacterial Canker Description: Infection causes sunken, oozing cankers to form on trunks or limbs. May cause wilting or death of branches or trees. Cherries are very susceptible, as well as other stone fruit, pears, apples and ornamentals. Bacterial Leaf Spot Bacterial Leaf Spot Description: Infected plants have water soaked spots, sometimes with a yellow halo, usually uniform in size. The spots enlarge and will run together under wet conditions. Under dry conditions the spots have a speckled appearance. Blossom End Rot Blossom End Rot Description: A serious disorder of tomato, pepper, and eggplant. Growers often are distressed to notice that a dry sunken decay has developed on the blossom end (opposite the stem) of many fruit, especially the first fruit of the season. Brown Rot Brown Rot Description: Brown rot is a major disease of all stone fruit and can cause major crop losses in peaches, cherries, plums, prunes, nectarines, and apricots. The fungus may attack blossoms, fruit, spurs or twigs and small branches. Cedar Apple Rust Cedar Apple Rust Description: A fungal disease found on the leaves of apple and crabapple. Symptoms initially appear as small yellow spots, which later enlarge and turn orange. Cedar apple rust will also attack various juniper species (red cedar). Club Root Club Root Description: Club root of cabbage and related crops is a serious disease in North America. Infected plants may grow slowly, appear wilted or stunted and have large galls or clubs on their roots. Club root can cause total plant loss. Corn Smut Corn Smut Description: Corn smut is easily recognized by the galls that form on any above ground plant part. As the galls mature, the interior darkens and turns into masses of powdery, dark olive-brown to black spores. Crown Gall Crown Gall Description: Crown Gall is a common disease of many woody shrubs and some herbaceous plants, including grapes, stone fruits and roses. Galls typically occur at the crown of the plant, just above soil level. Damping Off Damping Off Description: A result of soil borne fungi, damping-off usually refers to the disintegration of stem and root tissues at and below the soil line. Seedlings become water-soaked and mushy, and simply topple over. Dollar Spot Dollar Spot Description: Dollar spot, a disease of closely mowed turf grasses appears as round, brown to straw-colored and somewhat sunken spots approximately the size of a silver dollar; thus, the common name "dollar spot". Downy Mildew Downy Mildew Description: Downy mildew appears on the upper leaf surface as pale green or yellow spots. The spots look slightly gray and fuzzy when viewed from below, especially during periods of high relative humidity. Early Blight Early Blight Description: Common in potato and tomato, early blight first appears on lower leaves as small brown spots with concentric rings that form a "bull's eye" pattern. Infected leaves turn yellow and die.