Effect of periodic water Stress and salinity of Caspian Sea water on wheat yield and Yield components

Saline waters such as sea water in earlier years was considered as unusable, but new researches in two past decades have shown that irrigation scheduling based on using saline waters is applicable. The purpose of this study is investigation of simultaneous effect of periodic water stress and salinity of sea water on wheat yield. The research is based on factorial experiment in completely design (CRD) including 20 treatments and 3 replication in Gorgan University of Agriculture on autumn 2011. Periodic water stress in four stages (Initial, development, midseason and final stage) and salinity stress of sea water at 5 levels (0% 25%, 50%, 75% and 100% of Caspian sea water mixture into ordinary water) with Salinity of 0.7, 4.1, 11.1, 18.11, 25.1 (dS/m) respectively were applied. Result showed that periodic water stress and salinity of sea water on number of ears of plant, seed yield, Biological yield, seed weight and harvest index were significant at 1% level. The highest yield was observed in control treatment and then was for 25% sea water level without water stress. In 75% and 100% sea water and in development stage stress, the seed yield was reached to zero. Thus final stage water stress and 25% sea water salinity rate might be used for wheat cultivation near Caspian Sea lands. The using of sea water in different treatment cause to increasing soil salinity in salinity treatments during development stage (97% increase compared to control) led. Due to the problems same as salinity and water shortage in most parts of the country, use of Caspian Sea water (25% mixture with ordinary water) at final stages for wheat cultivation is applicable.