My question involves landlord-tenant law in the State of: Virginia

Question is Can Landlord raise rent........Lease states a month to month agreement. (pre-typed) at one rate. Both parties (landlord & Tenant) agreed to one year lease. So at the bottom of the agreement it was handwritten in that the lease is good for one year. ( sept 2015-sept 2016) both parties signed. Now can the landlord rightfully raise the rent in Jan 2016? Even though at the bottom of the lease it is written in for one year. Or since the year was written in by hand does that void out the month to month?