Pumpkins and Melons are harvested when they grow on top of hoppers

Currently, gourds like pumpkins and melons require an empty dirt block beside the plant where the gourd can grow. I would like to add “on top of hoppers” as a viable growing place. When the melons and pumpkins grow there, they are automatically harvested by falling into the hoppers. This would greatly improve crop density, productivity, and resource cost of automatic farms by removing pistons, observers, and redstone.