Two field experiments were carried out for the two successive growing seasons of 2012 and 2013 in a clay soil at the Experimental
Farm of the Faculty of Agriculture, Benha University, Qalubia Governorate, Egypt. The aim of this study was to select the appropriate
irrigation system; i.e. surface drip irrigation (SDI), gated pipes (GP) with long furrow and traditional furrow irrigation (TFI) systems for
irrigating sunflower (Helianthus annuus L.) plants under old lands conditions in Egypt, and to study the effect of irrigation water regimes
(100%, 75% and 50% ETc) on yield and its related parameters, water use efficiency (WUE) and soil moisture distribution. Results
showed that drip irrigation and gated pipes furrow irrigation systems exhibited the highest values of WUE for both seed yield and oil
yield meanwhile traditional furrow irrigation (TFI) recorded the lowest values in the same concern. The highest values of seed yield/fed.
(1280 kg/fed.) and oil yield/fed. (478 kg/fed.) were achieved by 75% ETc treatment. However, 50% ETc surpassed 100% and 75% ETc
in WUE for seed yield (0.62 kg/m3) and oil yield (0.232 kg/m3). Minimum water stress before and after irrigation occurred under GP then
surface drip and then traditional furrow irrigation. Reduction in average depth of contour line of field capacity after irrigation and
reduction in average depth of contour line of permanent wilting point before irrigation indicates a decline in the influence of water stress
on the cultivated plants. There is a big increase in water stress under 50% of ETc compared with 75% and 100% of ETc. There is a small
increase in water stress under 75% of ETc compared with 100% of ETc. It could be concluded that under the conditions of the experiment
or any other similar conditions, irrigation at 75% ETc, using drip or gated pipes with long furrow irrigation systems are recommended due
to their superiority in seed yield/ fed. with higher water use efficiency (WUE) and consequently higher net profits/ fed.