The Plant Clinic received 656 woody ornamental samples this year. These are some of the major problems we detected in 1999. The list is not intended to represent any sort of survey of problems in Illinois. It is merely a listing of the problems that occurred repeatedly that were sent to the Plant Clinic. An example of a disease that is not listed but still prevalent is sycamore anthracnose. That disease was once again very common in 1999, but most people recognize the disease and do not send it to the lab for confirmation.
Ash—anthracnose, Verticillium wilt
Crab apple—scab, cankers
Elm—Dutch elm disease
Maple—anthracnose, Verticillium wilt, Botryosphaeria canker
Oak—anthracnose, leaf blisters, oak wilt, cankers, bacterial scorch
Pine—pine wilt, Sphaeropsis blight, brown spot, Dothistroma blight
Spruce—Rhizosphaera needle cast, Sirococcus blight, Cytospora canker