Update Metadata field value using object model from TaxonomyWebTaggingControl

TaxonomyField managedFieldDept = (TaxonomyField)list.Fields["Department"]; TaxonomyFieldValueCollection DeptValues = new TaxonomyFieldValueCollection(String.Empty); DeptValues.PopulateFromLabelGuidPairs(controlDept.Text); TaxonomyFieldValue DeptValue = DeptValues[0]; managedFieldDept.SetFieldValue(itemSelected, DeptValue);