Foliar Application of Potassium Silicate Suppresses Wheat Aphid (Sitobion avenae) Infestation and Improves Yield Attributes of Wheat (Triticum aestivum L.)
Field-based alternatives to repeated insecticide use are needed for wheat aphid management. This study evaluated foliar potassium silicate at 0.5, 1.0, 1.5 and 2.0% for suppression of wheat aphids and improvement of yield attributes in wheat (Triticum aestivum L.) under field conditions at Khalsa College, Amritsar, Punjab, India, during the 2024–2025 Rabi season. The experiment followed a randomised block design with five treatments and three replications. Potassium silicate was applied at crown root initiation, tillering and jointing, while the untreated control received water sprays. Aphid populations were recorded weekly from the 8th to the 15th Standard Meteorological Week, and grain number per spike, test weight and grain yield were measured at harvest. Aphid abundance increased to a maximum during the 12th Standard Meteorological Week and declined thereafter. Potassium silicate significantly reduced aphid abundance in a concentration-dependent manner. The 2.0% treatment recorded the lowest seasonal mean aphid population (23.7 aphids per 10 plants), compared with 51.3 aphids per 10 plants in the untreated control, corresponding to a 53.8% reduction. The same treatment produced the highest grain number per spike (52.4), test weight (46.3 g) and grain yield (49.6 q ha⁻¹), with grain yield 22.2% higher than the control. Under the conditions of this study, foliar potassium silicate, particularly at 2.0%, was associated with lower aphid infestation and improved wheat yield attributes.