Agronomic responses of selected improved sorghum [Sorghum bicolor (L.) Moench] varieties to scheduled water stress

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.

第13个可持续发展目标敦促采取紧急行动以应对气候变化及其影响。在这一背景下，对具有高气候适应性潜力的作物在干旱耐受性特征方面的持续评估显得尤为迫切。2022年（8月至12月）在温室研究中，对三种改良高粱品种（SAMSORG 44、SAMSORG 47、SAMSORG 48）在严重水分胁迫条件下的农学反应进行了调查，该研究采用了一个3 x 3的完全随机设计（CRD）的析因实验，实验材料以塑料盆排列。在播种后21天（营养生长阶段）和50%花期（生殖阶段）分别施加三种土壤水分胁迫水平[充足灌溉（WW）、中度干旱胁迫（MDS）和严重干旱胁迫（SDS）]，分别对应于分数土壤有效水分（FSAW）的100%、50%和25%。所测量的所有农学参数（物候、生长、产量及其构成）均未受到干旱胁迫的显著影响（p<0.05）。水处理与品种之间存在显著（p<0.05）的相互作用。根据分数土壤有效水分（FSAW）在营养生长和生殖阶段的动态变化，三种高粱品种对干旱胁迫的反应存在显著差异（p<0.05）。SAMSORG 48在生长方面表现出更高的耐受性，而SAMSORG 44在所有水分处理水平下均产生了更高的种子产量和产量构成。所有品种在两个阶段均未受到干旱胁迫的影响。这些品种在严重干旱耐受性方面显示出高度适宜性。SAMSORG 44的表现相对更优，这体现在其更高的严重水分胁迫耐受属性上。