Maybe if the price per apple goes up, the grocer takes the money. He can’t sell more apples because there aren’t any right now and anyway there’s still the same number of stomachs, so he puts it in the bank. The bank lends it out at too high interest for the farmer to borrow to plant trees on the off chance he can convince the grocer to stock more apples five years from now.
IANAE but I think the idea is high interest rates prevent supply expansion generally.