Greetings Marsha:
Wow, I get a lot of these questions, "How to stop trees from fruiting." Unfortunately, a homeowner doesn't have many options: remove the tree, learn to live with the trees natural tendency to propagate, or "try" using a plant flower growth regulator such as ForelĀ® Fruit Eliminator.
I absolutely do not have any experience with Florel Fruit Eliminator so I'm at a complete loss with regard to telling you how effective such a treatment would be. If you want more information regarding such chemical growth regulators, please contact the manufacturer of Florel Fruit Eliminator or contact your local county Extension horticulturist.
Best of luck!