Two field experiments were carried out during growing seasons 2010 and 2011; it was executed in Abo-Ghaleb farm, Cairo-Alex. Rood, 60 Km away from Cairo - Egypt, to study the effect of two irrigation systems (surface and subsurface drip irrigation and three water application rates (50, 75 and 100% from actual irrigation requirements) and three types for pulse irrigation (2 times per day, 3 times per day and 4 times per day and time-off between pulses was 30 minutes) with continuous drip irrigation (one time per day)). The following parameters were studied to evaluate the performance of pulse drip irrigation: (1) Clogging ratio of emitters "CRE", (2) Emission uniformity "EU" (3) Application efficiency "AE", (4) Irrigation water use efficiency of potato "IWUE potato" or water productivity. The results indicated that, CRE decreased by increasing the number of irrigation pulses at (100%, 75% and 50% from WRa) under surface and subsurface drip irrigation. This may be due to pulse technique (cycle on-off) created turbulence in the flow channel and this turbulence prevent particles suspended from accumulation in flow channel and outlets of emitters. The values of CRE under pulse surface drip irrigation were lower than values of CRE under pulse subsurface drip irrigation, this may be due to pulse technique makes vacuum in the network and this vacuum with subsurface drip system will pull more particles which around the emitters through inlets of emitters. From the data of EU, it increased by increasing the number of irrigation pulses (100%, 75% and 50% from WRa) under surface and subsurface drip irrigation. This was due to the positive effect of pulse drip irrigation on reducing CRE. (3) AE increased from 89% under continuous drip irrigation to maximum value where it become 94% after applying pulse technique with 4 pulses at 100% from water requirements under surface drip irrigation, recording an increase of 5.3%. (4) IWUE potato or water productivity increased by increasing number of irrigation pulses especially at (100% and 75% from WRa). IWUE potato increased from 1.44 (kg/m 3) under CDI to maximum value, where it become 2.36 (kg/m 3) after applying pulse technique with 4 pulses at 75% from WRa under SSDI, recording an increase 63.9%, this mean that can save 25% of water requirements per season which equal 2085.6 m 3 ha -1 from irrigation water.
