The islanders suffer different odd effects upon discovering a crate of weird vegetables washed up on shore.
I have to admit this episode is different, the idea of eating found food has got to be slightly clever for a comedy - the most done with the theme since might be George eating an eclair on top of the garbage in "Seinfeld". So, I might give this installment some credit as being clever.
From there on, it is "Gilligan's Island", so while the professor can explain the radioactive effects (after finding the printed warning), he fails to prevent anyone from actually eating them as a matter of common sense. Therefore Gilligan gains super strength after eating spinach, Mary Ann can see hundreds of miles out to sea after eating carrots, and Mrs. Howell scurries around in fast-forward because of sugar beets. The biggest laugh is the idea of giant mutated vegetables appearing out of nowhere - almost like having Skylab landing in the yard.
I actually think this is one of the better episodes of "Gilligan's Island", it's just not up to the standard of passable television for me.