A backpack material dispenser that includes a pumpless pressure tank for storing and discharging a material under pressure contained in the pressure tank and a hose and a shut off valve connected to an output opening of the pressure tank for allowing flow of the material from the pressure tank under pressure and through a nozzle communicating with a discharge end of the hose. A discharge valve communicates with the nozzle proximate the hose for allowing controlled discharge of the material from the nozzle. A backpack assembly mounts the pressure tank for being carried by a user. A charging tank contains a gas under pressure to charge the pressure tank to a predetermined pressure, and a releasable connector of the charging tank attaches to a complementary connector of the pressure tank for charging the pressure tank with the gas under pressure to the suitable pressure tank pressure.