Investigation of aplication uniformity of emitters with different stuctural characteristics and produced by different manufacturers

ABSTRACTThe efficiency of a trickle irrigation system depends directly on the flow rateuniformity of the water discharged from the emission devices throughout the system.Ideally, all drippers should discharge an equal amount of water in the system. However,differences in design and manufacturing of drippers, important factors on irrigationsystem performance, can cause an unequal flow rate of drippers.Although similar or exactly same technologies are employed in manufacturingmany different types of drippers produced today, some variations may arise during theproduction stage. In this research, we investigated the effects of such variations on theuniform water distribution, using 17 different dripper types broadly used in Turkey.Fifty drippers were chosen from each type of dripper systems and their pressure-flowrate relationship were determined under 6 different pressure levels (0.5-3.0 atm) with 3replications. Research results showed that manufacturing variation coefficients (Cv) ofthe foreign manufactured drippers were lower than those manufactured in Turkey. Also,in-line drippers had lower Cv values than on-line drippers. In relation with these, theemission uniformity (EU), Christiansen uniformity (Cu) and statistical uniformity (Us)coefficients were higher in the foreign manufactured drippers and in-line drippers whencompared to local products and on-line drippers, respectively.Key words: Dripper or emitter, coefficient of manufacturing variation, emitterperformance, irrigation uniformity.II