Could you imaging the tech path and commitment for an endo to grow potatoes in space for the sole of spattering over the face of another endo?
First would have to build a pressure controlled room, with the right mixture of O2,CO2,N2,H2O.
Then you need to make the soil, Endo's don't poop so you it is harder to find all the required microbes and organic matter.
Then you need to get the lighting working without the radiation (might have to build near a planet to make use of the geomagnetic field as a radiation shield).
Then you maintain this for a few weeks to get you first potato.
You load the potato into your launcher and fire it at another endo hitting him in the face,
The potato explodes leaving the endo with creamed potato on his face (due the structural integrity of a potato vs harden steel Armour)
That endo with potato on his face, pulls out his rail gun, insert a random bit of metal and fires it a high velocity back at your face causing your head to explode out into a mist of endo.
Due to the amount of energy that producing each potato vs rail gun round (that just needs to be a magnetic metal or alloy) each potato is going to cost thousands of times more then railgun ammo, and still be impractical. It is going to be like wiping your butt with $100 notes.