Biomass Sorghum (Sorghum bicolor) Agronomic Response to Melanaphis sorghi (Hemiptera: Aphididae) Infestation and Silicon Application.

Abstract

Silicon application shows potential for enhancing crop resistance to pests while improving productivity. This study evaluated silicon's effects on agronomic traits and chemical composition of biomass sorghum (Sorghum bicolor) under aphid infestation (Melanaphis sorghi (Theobald, 1904) (Hemiptera: Aphididae)). Greenhouse-grown sorghum (hybrid BRS716) was treated with silicic acid (0, 2, 4, or 6 metric tons per hectare), applied at sowing and the five-leaf stage. Aphid-infested plants were monitored weekly for damage, alongside growth measurements (height, stem diameter, leaf retention). Post-harvest, fresh, and dry biomass were analyzed via near-infrared spectroscopy and chemical assays. Data were assessed using ANOVA and regression models. Results demonstrated that silicon reduced aphid infestation and damage at 6 metric tons per hectare. Silicon also increased cellulose content and improved phosphorus and calcium uptake, though nitrogen and potassium levels decreased. These findings suggest that silicon supplementation can strengthen sorghum's natural defenses, enhance biomass production, and modify nutrient profiles. This approach offers a sustainable strategy to mitigate aphid damage while maintaining crop yield and quality, with potential applications in integrated pest management systems.