Studying the effect of irrigation regimes and superabsorbent on proline and soluble sugars and their relationship with forage dry matter of sorghum

In order to investigate the possibility of decreasing sorghum water requirements with application of SAP and to investigate the relationship between the accumulation of proline and soluble sugars with leaf relative water content (RWC) and forage yield in sorghum variety Speedfeed this experiment was conducted in Dashtak region of Zahedan during 2013 and 2014 seasons in a split plot with four irrigation regimes, providing 40, 60, 80 and 100% of the water requirements of sorghum, calculated from pan evaporation as main plots, four amounts of SAP )0, 75, 150 and 225 kg ha-1( as subplots based on a completely randomized block design with three replications. The results indicated that the effect of irrigation regimes, SAP levels and interaction effects of two factors in all measured traits were significant. The regression models estimated for two years showed that although applying SAP in 100% ETc treatment had no effect on this trait in 2 seasons but the other irrigation treatments reduced the accumulation of proline and soluble sugars and increased the RWC and dry matter. Therefore, applying 75 kg SAP per hectare along with 20% decrease in the sorghum’s water requirement produced a dry matter yield Similar to 100% water treatment.