Silicon and arbuscular mycorrhizal fungi alter biomass partitioning and water-use traits in drought-stressed maize (Zea mays)

Silicon (Si) and arbuscular mycorrhizal fungi (AMF) have each been reported to improve drought tolerance in maize, yet their comparative effects on biomass allocation and plant water relations remain insufficiently understood. This study evaluated the effects of Si, AMF, and their combined application following a 7-day drought imposed at the vegetative growth stage. Leaf water-status traits were assessed immediately after drought, whereas morphological and biomass traits were evaluated following a 5-day recovery period after re-watering. Silicon significantly increased stem diameter (15.17 mm) and maintained the highest relative water content (88.33%), while AMF significantly increased leaf area (88.41 cm 2 ) and root dry weight (25.12 g). The combined Si + AMF treatment produced the greatest shoot dry weight (99.10 g), although root-to-shoot ratio, water saturation deficit, and water uptake capacity were not significantly affected. Principal component analysis explained 61.5% of the total variation and summarized associations among biomass- and water-related traits. Collectively, the results demonstrate that Si and AMF influenced different aspects of maize performance under drought, supporting their potential as resource-efficient approaches for improving maize production under water-limited conditions.