In the last 2 years my pear tree has had its leaves covered with orange discolouring and no pears are produced. Tiny mites are visible. Other trees in the neighbourhood have been affected. Can the tree be saved and/or cured before the season starts? I’ve had this tree for 35 yrs.
Unfortunately, this sounds like Pear Trellis Rust which is an incurable fungal infection (Gymnosporangium sabinae (G. fuscum) that arrived in Ontario from the west, probably on juniper trees. Unfortunately, no fungicides are registered in Ontario to control the disease. If junipers are on the property or neighbouring properties they are hosts and overwinter the rust. They should be removed or the pear tree will continue to become reinfected. Junipers need to be kept at least 1km away from pear trees to avoid the spread of this airborne disease. Probably impossible in an urban setting so monitor nearby junipers for telltale galls and remove infected branches from junipers in the dormant season and destroy.
As this tree is very old and precious perhaps it would be worth spending money to consult with a qualified arborist.
The following websites should be helpful. However, the tree may need to be removed. (See the City of Toronto for bylaw regulations at www.toronto.ca/faq/trees.htm)
Go to the following and enter rusts in the search bar