Q.No Fruit On Plum Tree
My Golden Transparent Plum planted in 2016 has produced no fruit. It is self fruitful and planted in almost full sun. Nearby Gage Plum is producing fruit. Some problems with Black Knot that I treat with copper spray and remove affected branches quickly. Could this be the reason there is no fruit? Plenty of blossoms that never develop into fruit.
Certified GKH Gardening Expert
This is, most certainly, the reason for lack of fruit production, unfortunately.
These articles will help:
https://www.gardeningknowhow.com/edible/fruits/plum/plums-with-black-knot-disease.htm
https://www.gardeningknowhow.com/plant-problems/disease/black-knot-tree-disease.htm
The Black Knot diminished over the past few years. I am now getting only one branch per season. If the Black Knot is supposed to weaken the tree, I don't see it. The tree looks healthy with clean green leaves and plenty of new growth. I could imagine the Black Knot possibly reducing the fruit output, but not shutting it down completely. I would look for other causes.