Just purchased small farm here in Florida a year ago. The property has this old Pear tree with some sort of disease I would like to identify and treat. From the attached pictures can anybody tell me what I am dealing with?
Answer The problem is most likely cedar-quince rust or a related rust problem. This fungus requires two hosts. Fruiting structures and spores are formed on cedar (Juniperus spp.) in the spring and they blow to the quince, pears, and other related plants. The fruits are infected and through the summer, the fungus matures within the pear and will later produce the spore structures shown in your images. These spores blow back to the cedars and the cycle starts over.
You may also notice leaf spots on the pear if the infections are not stopped. The best treatments are to remove cedar trees in the vacinity and to spray the pear with a fungicide in the spring, when the orange colored fruiting structures are visible on the cedar trees. Check out the factsheets and they will show images of what to look for on the cedars.
Plant diseases affecting vegetables, fruits, nuts, lawns, trees, shrubs and ornamental plants. I have just volunteered as an expert on this site as of 01/2011.
Identification and management of plant diseases. Have been employed as a Plant Disease Diagnostician since 2002 and currently work in the Plant Disease and Insect Diagnostic Laboratory at the Oklahoma State University.
Organizations National Plant Diagnostic Network, Great Plains Diagnostic Network
Education/Credentials B.S. Biology - Lebanon Valley College; M.S. Plant and Soil Sciences,concentration Plant Pathology - University of Delaware; Ph.D. in progress - Oklahoma State University.
Past/Present Clients Home gardeners, Hobbiests, Plant Breeders, Extension Educators, Nurseries, Greenhouses, Golf Courses, Departments of Agriculture, Industry professionals