An irrigation machine is selectively converted into a sprayer for applying chemicals that have been approved for use only by spraying equipment. A method is disclosed for irrigating and spraying crops using the same conduit connected to either an irrigation ground water source or a sprayer-approved chemical source, but at no time is the conduit connected to both sources simultaneously. The method includes connecting the input of a conduit to a ground water source, irrigating the crops with water from the ground water source, disconnecting the input of the conduit from the ground water source, connecting the input of the same conduit to a sprayer-approved chemical source, and spraying the crops with chemical from the chemical source.