Abstract: Liquid discharge apparatus, particularly useful as a portable inoculation gun for anti-virus inoculation of plants, includes a housing having a handle at one end configured for convenient grasping by a user, a nozzle at the opposite end for discharging liquid from a discharge opening therein, and a maniputable member manually actuatable to produce a discharge of liquid from the nozzle. The nozzle includes a gas passageway communicating with the discharge opening, and a liquid passageway communicating with the gas passageway. A gas delivery system is actuatable by the maniputable member to discharge gas at high-velocity through the discharge opening via the gas passageway. A liquid source communicates with the liquid passageway in the nozzle such that each high-velocity discharge of gas from the nozzle via the gas passageway draws a quantity of liquid from the liquid source into the gas passageway and discharges it at high-velocity with the gas through the discharge opening.