Whilst we're playing with the Transparency Tool, we can use it to darken the top of the pumpkin as well. Duplicate the top rectangle (Ctrl K). Apply a Linear Transparency adjusting the fill path arrow as shown.

NOTE: Since I have all this space it might be good to cover the difference between Ctrl D (duplicate) and Ctrl K (clone). Ctrl D creates a duplicate and offsets the duplicate the amount specified in the Page Options dialog.

Ctrl K (clone) creates a duplicate directly on top of the object being duplicated.