Apples drop from trees due to infestation.
Pigs eat apples, preventing reproduction.
You think monoculture farming might be really, really stupid? Like, clearly this is pretty much how the apple trees evolved to do this – drop the fruit when there’s a problem, and something will eat it. Fence off the apples, keep out the mammals, and the natural defense mechanisms are broken.
Monoculture is stupid. Throw rocks at it.