Q.Lapin cherry tree fruit shriveling up and leaves turning brown
Can you tell what is causing fruit to not properly develop and leaves to turn brown. The tree is about 8 years old and has produced a few small crops in past years. There is a significant number of fruits on the tree, but they remain small. Several limbs of the tree have had their leaves dry and turn brown.

This looks like Verticillium Wilt. It is a fungus that lives in the soil and will slowly deteriorate plants. The wilted leaves on only a few select branches indicates this type of fungus. It can be a tricky fix but it is possible to cure the soil. I am attaching a link that has more info.
https://www.gardeningknowhow.com/plant-problems/disease/verticillium-wilt-treatment.htm