Apples and pears.  Seem to be droppjng prematurely,
 the abscission layer on the apple stem was dark or mature.

Many FBclients and my own pears and apple
have started to drop early.
1 - This looks like it is environmental, part of the
 too hot and too dry periods.
2 - the abscission layer where the stem attaches
 to the branch.
3 - Commercial orchards in Oregon and Washington
don't seem to be having this problem.
4 My first guess was the weather but now after looking
at the commercial orchards, I am thinking more uniform
watering may have slowed the drop.  I know my
watering is very infrequent.