Q.ash tree seeds
Is it true that you can use a piece of copper wire around a tree to prevent it from producing seeds? The tree is an ash and drops thousands of seed every spring. We were told to wrap copper wire around the tree and keep tightening it.

This is actually likely to kill the tree. Copper is rather toxic to the tree and tightening the wire will essentially slowly girdle the tree, which could eventually kill it. It is possible that the stress to the tree from such a tactic could reduce the energy it has towards producing seeds, but the long term effects would not make it worth it.
I would recommend that you actually try to improve care to the tree. Trees will often increase the number of seeds produced if they feel stressed. Make sure the tree is getting enough water and is fertilized regularly. You can also hire a tree care professional to spray your tree with a chemical that will help to sterilize the tree. It is not 100% effective with ash trees, but can significantly reduce the number of seeds. This chemical needs to be applied yearly.