Two irrigations under CPE50 resulted 9 Mg ha−1 yield increment compare to rainfed condition. The same was 12 Mg ha−1 more under five irrigations treatment. Thus, additional three irrigations amounting 90 mm enhanced the yield by only 3 Mg ha−1. Therefore under limited water, irrigation application with moderate (CPE50) level is highly desirable instead of high frequency (CPE25) irrigation. Under such cases the additional three irrigations can be employed to bring out more (1.5 times) land under irrigation with 52 Mg ha−1 more yield. ▶ Among different mulches, RSM and WPM significantly increase yield to the tune of around 7 Mg ha−1 compare to NM condition. On the other hand black polythene mulch has the capacity to increase fruit yield by 16 Mg ha−1 in expense of less water compare to NM condition. So BPM could be a good management option for tomato cultivation in the Lower Gangetic Plain of eastern India. ▶ There was a close interaction between irrigation frequency and actual evapotranspiration rate (ETR). Thus, interval between two consecutive irrigations greatly influenced the ETR value. Increase in irrigation frequency promoted more unproductive loss of water by surface evaporation. The same was decreased with the decrease in frequency of irrigation. Maximum ET rate occur under bare soil condition, which minimized by different mulches in the order of RSM > BPM > WPM. ▶ The highest WUE value (21.6 kg m−3) was noted when two irrigations was applied (CPE50) and the same was at the lowest point when five irrigations were supplied to the crop. Among different mulches the values were in the order of BPM > RSM > WPM > NM. ▶ Finally it can be concluded that, under water scarce situation adoption of deficit irrigation clubbed with black polyethylene mulch can be a good option for utilizing water resource most efficiently without significant decrease in yield.