Laboratory experiments were carried out at Water Relations and Field Irrigation Dept., National Research Centre (NRC), El-Dokki, Cairo, Egypt to evaluate hydraulic parameters for five emitter types and select the best for applying in field experiments at NRC farm. Then a field experiment was conducted in Research and Production Station, NRC, El-Nobaria, El-Beheara Governorate, Egypt, in 2015/2016 to study the effect of selected emitter's types under different water salinity, on the plant growth characteristics and yield of turnip crop.
Lab experiments were conducted to evaluate hydraulic parameters for five emitter types [On-line emitter NEIN-ETF, Built in (GR), pressure compensating emitters (NEIN-PC), Pressure compensating and Self-flushing emitter (EDEN-PC)and On-line Commercial Katif emitter (KATIF-R-P-201] under water salinity (345, 2000, 4000, 6000, and 8000 ppm) and different operating pressure heads (0.8, 1.0, 1.2, 1.4,1.6, 1.8, and 2 bar). While in field experiment which was carried out to study the effect of some selected emitters [On-line Commercial Katif (CK), Built-in GR (GR), and On-line NEIN ETF, (ETF)] under different water salinity, (2000 and 4000 ppm in addition to the canal water, 345 ppm) on the plant growth characters and yield of turnip (Brassica rapa L).
Results of a lab experiment, in the case of using NPC1, NPC2 and NPC3 at using water salinity 345, 2000 and 4000 ppm were the highest in application efficiency, uniformity coefficient. It could be concluded that emitter types of NPC1, NPC2, and NPC3 under using water salinity 345, 2000, and 4000 ppm were the best and could be recommended to apply in the field research work.
According to field experiment, data revealed that the highest values of the estimated plant characters were attending at 345 ppm water salinity under all examined emitters. Emitter NPC1 gained the highest yield value (22.28 ton/fed) and NPC3 got the lowest one (19.23 ton/fed), while NPC2 emitter has a superior effect on yield and recorded the highest values which ranged from 27.5; 19.1 ton/fed at 354; 4000 ppm and 12.99, 8.22 kg/m3, respectively, while Emitter NPC1 gained the highest yield value (22.28 ton/fed) and NPC3 got the lowest one (19.23 ton/fed) with difference 16 %, while NPC2 recorded the highest water use efficiency, WUE (10.77 kg/m3). WUE for examined emitters, NPC2 had a positive effect and recorded increase about 14.5 %(NPC1) and 17.4 % (NPC3). The rate of reduction in yield and WUE relative to salinity were 20 and 35 % for irrigation water salinity 2000 and 4000 ppm relative to control one (345 ppm).