treeList1.OptionsMenu.EnableColumnMenu = true;
treeList1.OptionsMenu.EnableFooterMenu = false;

TreeList1.OptionsMenu.EnableColumnMenu = True
TreeList1.OptionsMenu.EnableFooterMenu = False

using DevExpress.XtraTreeList;
//...
private void treeList1_ShowTreeListMenu(object sender, DevExpress.XtraTreeList.TreeListMenuEventArgs e) {
   TreeListHitInfo hitInfo = treeList1.CalcHitInfo(e.Point);
   if(hitInfo.HitInfoType == HitInfoType.Column && hitInfo.Column.Caption == "Department")
      e.Allow = false;
}

Imports DevExpress.XtraTreeList
'...
Private Sub TreeList1_ShowTreeListMenu(ByVal sender As Object, _
ByVal e As DevExpress.XtraTreeList.TreeListMenuEventArgs) Handles TreeList1.ShowTreeListMenu
   Dim HitInfo As TreeListHitInfo = TreeList1.CalcHitInfo(e.Point)
   If HitInfo.HitInfoType = HitInfoType.Column And HitInfo.Column.Caption = "Department" Then
      e.Allow = False
   End If
End Sub