A liquid spray system adapted to spray a field of plant foliage comprising: a liquid supply boom for travel in a direction of movement, a plurality of spray nozzle assemblies mounted on a respective liquid supply stem fixed in depending fluid communication on said boom, said plurality of nozzle assemblies supported in laterally-spaced relation along said boom for travel in the direction of movement of the boom, each of said liquid spray nozzle assemblies having a nozzle body with a liquid inlet in fluid communication with said liquid supply boom and a liquid flow passage extending along an axis of said nozzle body, characterised by, said nozzle body having: a first liquid discharge orifice for discharging pressurized liquid from said liquid flow passage and for directing liquid onto a first deflector flange surface oriented at a relatively small angle α to a vertical axis of the nozzle assembly in the direction of travel of the spray boom; said first deflector flange surface having a lip portion for directing pressurized liquid discharging from said first discharge orifice at said first angle α to said nozzle body axis in a leading direction relative to movement of said boom; and a second discharge orifice for discharging pressurized liquid from said liquid flow passage and a second deflector flange surface for directing discharging liquid from said second discharge orifice in a trailing direction relative to said movement of said boom and at a second angle φ to said nozzle body axis different from said first angle α. a liquid supply boom for travel in a direction of movement, a plurality of spray nozzle assemblies mounted on a respective liquid supply stem fixed in depending fluid communication on said boom, said plurality of nozzle assemblies supported in laterally-spaced relation along said boom for travel in the direction of movement of the boom, each of said liquid spray nozzle assemblies having a nozzle body with a liquid inlet in fluid communication with said liquid supply boom and a liquid flow passage extending along an axis of said nozzle body, characterised by, said nozzle body having: a first liquid discharge orifice for discharging pressurized liquid from said liquid flow passage and for directing liquid onto a first deflector flange surface oriented at a relatively small angle α to a vertical axis of the nozzle assembly in the direction of travel of the spray boom; said first deflector flange surface having a lip portion for directing pressurized liquid discharging from said first discharge orifice at said first angle α to said nozzle body axis in a leading direction relative to movement of said boom; and a second discharge orifice for discharging pressurized liquid from said liquid flow passage and a second deflector flange surface for directing discharging liquid from said second discharge orifice in a trailing direction relative to said movement of said boom and at a second angle φ to said nozzle body axis different from said first angle α. a first liquid discharge orifice for discharging pressurized liquid from said liquid flow passage and for directing liquid onto a first deflector flange surface oriented at a relatively small angle α to a vertical axis of the nozzle assembly in the direction of travel of the spray boom; said first deflector flange surface having a lip portion for directing pressurized liquid discharging from said first discharge orifice at said first angle α to said nozzle body axis in a leading direction relative to movement of said boom; and a second discharge orifice for discharging pressurized liquid from said liquid flow passage and a second deflector flange surface for directing discharging liquid from said second discharge orifice in a trailing direction relative to said movement of said boom and at a second angle φ to said nozzle body axis different from said first angle α.