Kiwi = Giant Turtle.
Giant Turtle = Gamera.
Gamera = Famous Japanese Kaiju Monster that is apparently a complete bad ass, much like Godzilla.
Godzilla = Loved by chidlren.
By extension, Kiwi = Loved by Children.
Turnip = Vegetable.
Vegetable = Hated by Children.
Therefore, Turnip = Hated by Chidlren.
So when it comes down to it, all Kiwi has to do is summon an army of Pre-schoolers to his side, and at the first sight of Turnip...well, you know how crazed out 5 year olds can get.