It is known to load bales of agricultural products such as grass, hay, corn stalks and the like into flexible plastic tubing which are sealed and left on the ground to convert the material into desired silage, thereby eliminating the use of costly silos.  Such an apparatus is described, for instance, in Canadian patent 1,242,173 dated Sep. 20, 1988, inventor Maynard Good, entitled: "APPARATUS AND METHOD FOR LOADING PLASTIC TUBING WITH BALES".  However, the apparatus of this patent which is mounted on wheels must be hitched to a tractor which carries the power source necessary to actuate the pusher plate which sequentially moves the bales into the open-ended portion of the tube.  A driver must therefore be provided for the tractor and apparatus in addition to the driver operating the fork-carrying tractor which collects the bales scattered on the field and sequentially drop the same on the vehicle for loading. 
It is also known to provide a tubing which is stretchable, the tubing being stretched during bale loading and allowed to relax and tighten the loaded bales so as to diminish as much as possible the air content of the resulting bagging tube to thereby improve the quality of the eventual silage.  A system using resilient, stretchable, flexible tubing is described in the international patent application No.  PCT GB 9001820, published on Jun. 13, 1991 under international publication No.  WO 91-07867.  This application is entitled "SHEATHING APPARATUS" in the name of Ag Bag Corp. U.S.A. The apparatus described in this patent application requires the use of a farm tractor to move the same over the ground as shown in FIG.  3 and, moreover, the system for stretching the resilient tubing results in uneven stretching of the tube around its periphery and also cannot accomodate bales and tubes of different diameters.