Dynamics of root and shoot growth of barley under various levels of salinity and water stress

Abstract

Response of barley to water stress at different growth stages at various levels of soil salinity was studied in cylindrical wooden containers (1.1 m long and 0.6 m in diamer). The treatments consisted of three salinity levels (low = S 1, medium = S 2 and high = S 3) and two irrigation treatments, no water stress at any given growth stage and plants exposed to water stress at either tillering, vegetative, flowering or seed formation stage and normally irrigated in the other stages. Comparison in above-ground dry weights indicated a significant variation ( P = 0.05) between different treatments at each sampling date. The interaction between salinity and water stress was also significant. Maximum reduction in shoot dry weight was 70% under S 3 treatment when the plants were imposed to water stress in the vegetative growth stage. The relative reductions in shoot dry weights due to salinity at the vegetative growth stage were 33% and 46% for S 2 and S 3, respectively, in comparison to S 1. Root dry weights significantly varied between different treatments. The highest reduction in root dry weights was recorded when the plants were exposed to water stress and/or salinity at the vegetative growth stage. Linear relations between evapotranspiration and above-ground dry weights, grain yields and root dry weights were obtained. Regardless of water stress or salinity levels, barley grain, above ground dry weights, and root dry weights were correlated with evapotranspiration.