Show varni tractors will roll on oil steel tito the production of farm tractors requiring tires must bo be stopped after may alay 1 the war production board has ruled and from now until may I 1 the output of rubber tiro tire tractors will bo be sharply curtailed tile the rules was explained pla ined as a necessary rubber conservation measure the shortage of crude rubber will not permit manufacturers to maintain the production schedules upon willoh which they operated in january and february they must change swiftly from froin the use of rubber tiros tires to the uso UBO of steel wheel equipment |