Keep in mind that 44x2 is 88. This will be a tight fit since your quilt is 88x90 The length at 90" would would be 90/36= 2.5 yards. You always want to have 6" on each side if you were having it long armed. If you are doing it yourself leave a few inches where ever possible.
On this quilt I think your best bet would be to get a wide backing piece of backing as it is cutting it to close for comfort on the width. With a 108x 2.5 yards you would have more than enough.