evaluation of deficit irrigation levels on wheat grain yield cultivars based on water productivity indices

in order to study of deficit irrigation levels on wheat grain yield cultivars based on water productivity indices, an experiment was conducted in a split plot arrangement in randomized complete block design at the field of agricultural and natural resources center of isfahan (kabutarabad research station). three levels of irrigations: 60% of full irrigation (f1) and 80% full irrigation (f2) and full irrigation (as the check) were assigned to main plots and six wheat cultivars including: pishtaz, shiraz, sepahan, marvdasht, mahdavi and back cross of roshan were randomized in sub plots. the maximum total water productivity (twp) were obtained from fi treatment (60% of full irrigation) with 1.51 kgm-3 and with 1.22 kgm-3  respectively. it means  that  decreasing of irrigation water rate, up to 40% due to 16.6% yield reduction totally. the highest irrigation water productivity (iwp) were achieved from pishtaz (1.19 kgm-3)  and sepahan cultivars (1.15 kgm-3) respectively.