Crops can still be tended to with the mouse while mounted, which suggests that this behaviour is unintended.
How to fix:
Add the "tendable_farmplant" tag to the PICKUP_TAGS table that is located on line 73 of components/rider_replica.lua
Add the same elseif check that is on lines 1468-1469 of components/playercontroller.lua to the GetPickupAction function on line 51 of components/rider_replica.lua
Change self.inst:HasTag("mime") to inst:HasTag("mime") since the GetPickupAction function doesn't take self as an argument