It depends on where the hike is:
Dropping an orange peel in a humid, temperate, low-elevation place is vastly different than a desert, high-alpine, tundra or other environment where organics take a long time to decompose.
I'm mostly joking.. LNT is always the best policy, even if only (sometimes) for the feeling of pristineness.
Honestly orange peels are incredible, the smell, the robustness. It reminds me of the joke of the plastic cup at Whole Foods filled with orange slices. If only there was a natural packaging alternative...