Abstract: A yield monitor system for determining quantity of harvested sugar cane on a sugar cane harvesting vehicle is disclosed. The vehicle has a harvesting mechanism including a base cutter assembly for severing sugar cane from a field, a chopper assembly for chopping the severed sugar cane into billets, and an elevating assembly for elevating the billets during transport to a storage device, the elevating assembly having an elevator motor coupled to a pressurized hydraulic fluid source. The yield monitor system includes a sensing assembly and a control monitor. The sensing assembly generates a sensed signal representative of a quantity of harvested sugar cane being transported to the storage device. The control monitor receives the sensed signal and determines the quantity of harvested sugar cane therefrom.