By Barbarap
United Kingdom 
My mature pear tree , has always done well in the past except this year. The fruit this year are small and not very many. Some leaves are black. I've bought a tree disease book to help me and think it might be canker .If I treated the pear tree for this and it wasn't ? would it hurt the tree?
27 Aug, 2010
The canker treatment probably won't hurt your tree.
Few and small fruits sounds like drought.
28 Aug, 2010