An integral, discrete, drip irrigation emitter that comprises means for facilitating spreading of its water exit “pool” U configured, in cross section, “legs”, so that after affixing the drip emitter onto the inner wall surface of the hose, and following water pressure increase within the hose, an elastic movement of a sector of the hose's wall that is framed and delineated as a consequence of affixing the circumferential rim of the exit pool onto the inner wall of the hose, will take place onto opening a water outlet opening, and from the time the water pressure in the hose decreases, closing of the water outlet opening would occur, and a drip irrigation hose embedding at least one such emitter in it, and a general method for opening and closing water outlet openings in such hose, wherein the opening and closing is performed in accordance with and in correlation to the water pressure prevailing in the hose.