an safety control system especially useful for controlling the irrigation of crops . the system includes a transmitter having an extended range over two miles . a repeat cycle timer provides a repetitive time delayed input signal to the transmitter which transmits a signal while an irrigation system is operational . a receiver for receives the signal from the transmitter , and a time delay relay latches upon receipt of the signal by the receiver to close a circuit and provide power to a pump unit for a fixed amount of time . if the time delay relay times out without receiving a signal from the transmitter , the irrigation pump unit is shut off .