After determining that saccharin was bad for radishes, I kind of gave up on the radish experiment. I mean, I still watered them, but I didn't really expect to find anything. Today I got around to pulling them up (nearly a month too late). There were, as you'd expect from the previous post, a lot more of the control radishes (right) than the saccharin ones (left):

As for the final conclusion: I tasted some of each: I couldn't tell the difference with the roots, stems, or leaves. If there was a difference it was too subtle to notice.

Oh well. Negative results can be dull, but it's important to make them public.