Bales emanating from the discharge end of a baler are received on an accumulating trailer provided with a weighing scale that, in combination with an electrical system, automatically determines the weight of certain of the successively issuing bales and conveniently displays such weight to the operator in the cab of the towing vehicle so that the operator can monitor the quality and condition of bales prepared by the machine on an ongoing, non-stop basis. An onboard computer preferably forming a part of the electronic system controls the process and assures its accuracy, while also providing information such as the average weight of bales weighed since last resetting the system.