Amorphous Silica-Based Fertilizer Increases Stalks and Sugar Yield and Resistance to Stalk Borer in Sugarcane Grown Under Field Conditions

Silicon (Si) fertilization can mitigate biotic and abiotic stresses and increase the yield of sugarcane. Considering the low availability of Si in tropical soils and the large amounts of fertilizer required by Si accumulating crops, concentrated sources of Si with good solubility may lead to more profitable fertilization management. In this context, we assessed the potential of an amorphous silica-based fertilizer (ASF) on increasing the soil availability and uptake of Si by sugarcane, the growth parameters, the stalk and sugar yields, and the damage caused by stalk borer ( Diatraea saccharalis F.). Additionally, Si effects on the accumulation of nutrients by sugarcane were evaluated. The field trial was carried out in a randomized block design with four replications. The ASF was applied at five rates (0, 125, 250, 500, and 750 kg ha −1 ). The evaluation of the plants was performed 12 months after planting. Silicon available content in the soil layers assessed (0.0–0.2 m and 0.2–0.4 m) increased with Si fertilization. The Si concentrations in leaves and stalks were up to 5- and eightfold higher in ASF-amended plants than the control. The Si fertilization increased N, P, K, Ca, Fe, Mn, Cu, and Zn concentrations. Sugarcane growth parameters showed a positive relationship with Si in plants; the height and stalk diameter and the dry leaf biomass were 50, 58, and 71% higher in the 750 kg ha −1 ASF compared to the control, respectively. ASF also increased the contents of fiber, total sugar, and recoverable sugar. The accumulation of Si in the stalk reduced significantly the damage caused by the stalk borer. The ASF rates increased the yield of stalks, total and recoverable sugar, and the stalk borer’s resistance, having great potential to boost sugarcane performance in Si-depleted soils in northeast Brazil.