Achieving uniform water distribution and, consequently, improving the efficiency of a drip irrigation system depends on the proper hydraulic performance of the emitter as one of the main components of the system. Therefore, in this study, a laboratory experiment was conducted to evaluate the performance of four types of emitters available in the market (two pressure-compensating and two non-pressure-compensating) under five applied operating pressures (0.6, 0.8, 1.2, 1.6, and 2.4 bar). The evaluated parameters included distribution uniformity (EU), Christiansen’s uniformity coefficient (CU), manufacturing coefficient of variation (CV), discharge variation coefficient (qvar), discharge–pressure relationship and statistical uniformity coefficient (Us). The results confirmed the superior performance of the Eurodrip emitter among the non-pressure-compensating emitters (CV = 0.036, EU = 95.28%, CU = 97.26%, qvar = 23.2%, and Us = 96.18%). Among the pressure-compensating emitters, the Abafarin emitter exhibited better performance (CV = 0.082, EU = 87.36%, CU = 92.78%, qvar = 25.8%, and Us = 91.4%). Overall, the results indicated that, under the conditions of this study, the evaluated non-pressure-compensating emitters outperformed the pressure-compensating emitters in most hydraulic performance indices.

Therefore, in order to improve irrigation system efficiency, the selection of emitters should be based on the evaluation of hydraulic performance indices under actual operating conditions, so that their real performance can be accurately determined, rather than relying solely on manufacturers’ reported specifications.