evaluation of yield, yield components and water use efficiency of shahri and shirazi balangu (lallemantia sp) under drought stress for irrigation management

to evaluate the effect of water stress on yield and water use efficiency (wue) of lallemantia sp, an experiment was conducted as split plot factorial in randomized complete block design with three replications in the field of medicinal plants research center of shahed university, tehran in 1390-91. the first factor was irrigation system including 40 and 60 percent depletion of available soil water (asw), the second factor was lallemantia species including, lallemantia. iberica and l. royleana and the third factor was the origin of ecotypes, urmia and mashhad. water stress decreased leaf area index (lai) 31.07 percent of l. iberica significantly, but l. royleana didn’t change. the highest grain yield with an average of 208.4 kg.ha-1 obtained at 40 percent depletion of asw and related to l. iberica with an average of 189.4 kg.ha-1. grain yield decreased by 28.03 percent in shahri species but shirazi species showed11.11 percent reduction of yield. significant difference was seen in l. iberica ecotypes and mashhad ecotype in terms of grain yield, harvest index and water use efficiency with 38.76, 36.63 and 37.32 percentage, respectively showed the highest means compared with urmia ecotype but any significant changes was not seen in ecotypes of l. royleana. significant positive correlation was between wue and lai (0.44), seed weight (0.53), grain yield (0.98), biological yield (0.61) and harvest index (0.91).