Because the harvester has to fit the shape and
size of the tree or bush -- as well as the size of the fruit.
And some
trees take a lot more shakin' before they let go of their fruits. Orange
branches, for example, need four times as much force as these apple branches on
the right. But berries need only about one-fourth as much force as apples.
That's because berries don't all ripen at the same time, and more force would
detach the unripe berries along with the ripe ones.
Some
fruits even need to be coaxed to let go. Peterson's orange harvester (left) has
to make the oranges go in circles before they detach from the branches. But
cherries and apples fall off much more easily.
And some
trees take a lot more shakin' before they let go of their fruits. Orange
branches, for example, need four times as much force as these apple branches on
the right. But berries need only about one-fourth as much force as apples.
That's because berries don't all ripen at the same time, and more force would
detach the unripe berries along with the ripe ones.
Some
fruits even need to be coaxed to let go. Peterson's orange harvester (left) has
to make the oranges go in circles before they detach from the branches. But
cherries and apples fall off much more easily.