I have a piece of Undeveloped Land with a Mortgage and Property Taxes . Can I deduct the Mortgage Interest and Property Taxes ?

It depends.  If this is just land you own and will continue to own that you are not in the process of building a home or soon building your home, then no, it would not be deductible.

If this is part of the construction of your home, you can deduct it for 24 months BEFORE the completion of the house.  

"Home under construction. You can treat a home under construction as a qualified home for a period of up to 24 months, but only if it becomes your qualified home at the time it is ready for occupancy. The 24-month period can start any time on or after the day construction begins."  Pub 936