a) don't use such long items in your value list. Find a way to use a shorter representation of the same data. There are several ways to enter the longer text into a value once the shorter value that represents it has been selected.
b) don't use a value list at all. A selection portal may be set up where your data is listed in the rows of a portal where you can use a field sized two rows tall to display the data for a given item. The portal field can be set up as a button so that tapping it performs a script that enters the appropriate value into your field. To save space on your layout, such a control can be placed inside a popover.