Silicon amendment - influence on sorghum growth, yield, and nutrient uptake under water stress

Silicon enhances plant growth and development, alleviating the effects of biotic and abiotic stresses. Drought severe abiotic stress that hampers plant growth and production globally, posing threat to food security. Mass production of sorghum is crucial to eradicating the present increasing food insecurity in water-stressed regions. The study evaluated the effects of silicon on nutrients uptake, growth and yield of sorghum under different water regimes. A two-season field trial was carried out to evaluate two sorghum varieties (seredo and Machakos local red), silicon (with silicon and without silicon) under three irrigation regimes (20%, 40% and 60%) laid out in Randomized Completely Block Design in a factorial arrangement replicated thrice. Data was collected on growth, yield and nutrients uptake, which was subjected to analysis of variance using R software. Results showed that Seredo variety had the highest root dry weight (123.5 g) and longest roots (51.4 cm). At 60% water regime and silicon amendment enhanced sorghum growth better than other treatments. Seredo variety recorded the highest grain yield (4.82tha(-1)), phosphorus (95.53 kg ha(-1)), nitrogen (32.16 kg ha(-1)), K (76.06 kg ha(-1)), calcium (3919.00 kg ha(-1)) and magnesium (165.02 kg ha(-1)). Seredo had the maximum harvest index of 0.41. At 40% water regime, Seredo variety amendment with Si produced the highest grain yields and nutrients uptake. Si amendment can improve sorghum growth and yield under water stress conditions, as indicated by high grain yield and nutrients uptake achieved at 40% water regime. The use of Silicon is recommended for improving sorghum productivity in regions experiencing low rainfall.