Effect of Silicon Fertilization on Eggplant Growth and Insect Population Dynamics

Silicon (Si) is the second most abundant element known for its beneficial effects on plants especially facing biotic and abiotic stresses. This study was conducted to determine the effects of Si on the growth, uptake of mineral nutrients and insect population dynamics on eggplant. Plants were treated with Si through various sources viz., sodium silicate in soil (56 mg kg soil −1 ), sodium silicate sprayed on foliage (2 mM Si solution), rice husk and rice husks biochar in soil (equivalent to 56 mg kg soil −1 ). The results showed that Si improved plant physical growth attributes i.e., rice husk and rice husk biochar treatments increased plant height 24.60% and 16.95%, respectively, compared to Control treatment. Silicon in the root medium improved the phosphorus uptake (2.86 vs 3.21 mg g −1 in control vs rice husk biochar treated plants) and Si concentration (1.33 vs 6.53 mg g −1 in control vs Soil Na 2 SiO 3 treated plants) in leaves. Conversely, presence of Si in root medium decreased Ca concentration in plant leaves and the corresponding values were 1.43 vs 0.31 mg g −1 in control vs rice husk treated plants. Compared to control, Si-treated plants were less infested with insects i.e., jassid, whitefly and borer population was reduced in the range of 33.68–60.62%, 19.23–50.92% and 16.03–75.64%, respectively. Hence, it is concluded that rice husk and rice husk biocahr also could be used as a Si source to decreases the extent of insect infestation on eggplant and it could be a sustainable alternative strategy to reduce insecticide use.