LAUSR

ABSTRACT A field experiment was arranged in split plot based on randomized complete block design in three replications at Moghan plain, Iran, during the years 2014–2016. Treatments included four irrigation levels, 100%, 80%, 60%, and 40% of water requirements for the main plot, and tomato cultivars included for a subplot. Results indicated that deficit irrigation resulted in a decrease in yield and yield components, morphological characteristics and water use efficiency (WUE), and volumetric soil moisture in different layers of soil, while resulting in an increase in qualitative characteristics. Reductions of tomato fruit yield and other studied traits were different in the first and second agronomic years. But in general, comparison of means showed that, based on the normal irrigation, optimal growth and plant growth were observed for 08 cultivar. Moreover, under deficit irrigation conditions, Superbita cultivar exhibited higher yield and WUE compared to 08 and Matin cultivars. Abbreviations: WUE = Water use efficiency; IWUE = Irrigation water use efficiency; K = Kelvin; IR = Irrigation water; Cul = Cultivar; ETo = Reference evapotranspiration; Etc = Evapotranspiration; Kc = Crop coefficient; Kp = Pan coefficient; cm = Centimeter; gr = Gram; t = Tone; ha = Hectare; ɵ = Volumetric water content; kg = kilogram.