In order to studying the effects of salt and drought stress on biomass and seed production of Kochia, six experiments with 1.5, 7, 14, 21, 28 and 35 dS/m of saline water ( drainage water) was conducted individually. In each experiment three levels of deficit irrigation (25, 75 and 125% of water requirement) was applied based on randomized completely block design with three replications in Mazrae Nemoneh Research Station, Golestan Province , in north of Iran in 2008. The result of combined analysis showed that saline water had significantly effect on biomass and seed yield, lateral stem number, plant height and stem dry weight. Leaf dry weight and biomass production was affected by water quality and quantity significantly. There was no any significant difference between water quality and quantity. Effect of saline water was not significant up to 7 dS/m in any growth and morphological traits of Kochia and saline water threshold tolerance of this mesohalophyte (Kochia scoparia) in this research was 7 dS/m and 50% reduction of plant dry weight was reached at 38.16 ± 3.53 dS/m. Water productivity (WP) based on seed yield reduced with increasing salinity and volume of water application. The highest WP was observed at 7dS/m and 25% water use and the lowest WP was calculated at the highest water application and salinity (125% and 35 dS/m) of saline water, respectively.

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