SCIENTIA HORTICULTURAE, vol.219, pp.10-21, 2017 (SCI-Expanded)
This research was carried out to evaluate the effect of various irrigation regimes applied with subsurface and surface drip systems on yield, quality and midday leaf water potential (LWP) on eggplant in the Mediterranean Region of Turkey. The field experiments were carried out during the growing seasons of 2013-2014, in the experimental fields of Soil and Water Resources Research Unit in Tarsus. In the study, two irrigation systems namely surface drip (DI) and subsurface drip systems (SDI); two irrigation intervals (IF3: 3-day; IF6: 6-day) and four irrigation regimes (Full irrigation, Fl; deficit irrigations, DI-50; DI-75); and Partial Root-zone Drying PRD-50, which received, respectively 50, 75, and 50% of Fl were tested in split-split plot design with four replications. Leaf water potential were measured throughout the growing season with a pressure chamber. Irrigation methods, irrigation intervals and irrigation levels resulted in significantly different yields. Surface drip performed slightly better than the subsurface drip considering yield and quality of eggplants. The highest yield values were obtained from the full irrigation treatments DI IF3FI and SDI IF3FI with 3-day interval. In both trial years PRD-50 treatment in subsurface drip with 6-day interval plots resulted in the lowest yield. The highest water use efficiency (WUE) was found in subsurface drip 6-day interval deficit irrigation (SDI IF6 DI-50) (21.9 and 24.5 kg m(-3) in 2013 and 2014) and the lowest in subsurface drip 6-day interval PRD-50 (SDIIF6 PRD50) (12.2 and 16.6 kg m-3). LWP values in the surface drip irrigation treatments ranged between -1.11 and -1.55 MPa in 2013, and ranged between -0.98 and -1.48 MPa in the 2014 growing season. In subsurface drip irrigation treatments LWP values ranged between -1.0 and -1.51 MPa in 2013 and ranged between -0.91 and -1.43 MPa in the 2014. The LWP values decreased with increasing water stress. A significant linear relationship between LWP and yield was obtained. The results revealed that eggplant should be irrigated at LWP values between -0.95 and -1.05 MPa (-9.5 ile -10.5 bar) for high and good quality yields. Thus, LWP can be used for irrigation scheduling for eggplant. (C) 2017 Elsevier B.V. All rights reserved.