problems with my plum tree
How do I get rid of suckers and shoots around my backyard?
The best control is cutting/digging/pulling. Using an herbicide may damage the parent tree. Here's a discussion: https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-sucker-removal-and-tree-sucker-control.htm
If the sprouts are from a tree that you don't want to keep, you might try girdling, as in this discussion: https://www.gardeningknowhow.com/ornamental/trees/tgen/weed-trees.htm