https://www.rhs.org.uk/advice/profile?pid=114
this is the RHS advice for brown rot

https://www.rhs.org.uk/advice/profile?pid=662
and this is the one for your pear midge problem.

the RHS is the best advice so have a read and see if you can sort your trees. good luck with both trees :o)

Thankyou. I have checked the links and found them helpful.

Is your tree planted in a tub/container? The problem is most likely a nutrient deficiency. Much like blossom end rot on tomatoes. Fruit trees are extremely hungry/thirsty plants. Anything lacking will cause problems. When your plum tree goes dormant, try transplanting to a larger container with new grow medium.

Thankyou but my trees are in the ground. I have not really fed them much and wondered if I should clear the grass round the root