Question
My 10 year old plum tree finally produced its first dozen or  so small plums last year. This year it is just loaded with tiny plums that are covered with a clear sticky substance, some of which has solidified even as it has dripped from the plums. The coating has a candy apple dried syrup appearance. The plums fall off if you touch them. My hopes for a lovely crop are fast fading. I am in St Martins, New Brunswick, canada. What on earth is this?

Answer
Sounds like there is an insect involved.  Check the branches for small oval shaped structures closely appressed to the plant tissue.  They can be brown to black in color and do not move when touched, but can be scraped off with your fingernail.  If you find these the tree has scale insects.  The other option is a worm has invaded the fruit and is causing the fruit to weep the sap out.  Cut into a few fruit and see if you find any evidence of any bugs inside.  In most cases, fruit trees have to be sprayed with an insecticide to have a good crop of edible fruit.  If you find either of these problems, check with your local garden center for a fruit tree spray that you can use.  It may not be too late to salvage the unaffected fruit.  Next year, begin the sprays early in the season-- say at blooming and continue to spray several times during the growing season to prevent insects.  I hope this helps.  Good Luck.