Agronomic responses of selected improved sorghum [Sorghum bicolor (L.) Moench] varieties to scheduled water stress
Description
The 13th sustainable development goal urges to take urgent action to combat climate change and its impacts, in this vein, continued evaluation for drought tolerance traits in crops with high climate-smart potential is imperative. The agronomic responses of three improved sorghum varieties (SAMSORG 44, SAMSORG 47, SAMSORG 48) under severe water stress conditions were investigated in a screen house study in 2022 (August - December) as a 3 x 3 factorial experiment laid out in plastic pots arranged in a completely randomized design (CRD) with three replications. Three soil moisture stress levels [well-watered (WW), moderately drought-stressed (MDS) and severely drought-stressed (SDS) conditions] corresponding to 100, 50 and 25 % respectively of fractional soil available water (FSAW) determined gravimetrically were imposed on all the three varieties at 21 days after sowing (vegetative) and at 50 % flowering (reproductive) for 2 weeks respectively. All agronomic (phenological, growth, and yield and yield components) parameters measured, were not significantly (p<0.05) influenced by drought stress imposition. There were significant (p<0.05) interactions between water treatment and variety. The three sorghum varieties responded differently (p<0.05) based on the FSAW dynamics at both vegetative and reproductive stages. SAMSORG 48 demonstrated higher growth while SAMSORG 44 produced higher seed yield and yield components at all levels of water treatment and all the varieties were not affected by drought stress at both stages. These varieties have displayed high suitability for severe drought tolerance. SAMSORG 44 had comparatively superior performance as indicated by its higher severe moisture stress tolerance attributes.