Silicon Mitigates the Attack of Pests and Diseases on Ipê-Roxo (Handroanthus impetiginosus) Seedlings

Abstract

Silicon in plants is a structuring element that promotes water and saline stress tolerance and decreases transpiration. The silica accumulated in the cuticle establishes a physical barrier and helps fight against pests and diseases. The present study aimed to evaluate the development of ipê-roxo (Handroanthus impetiginosus) seedlings in different environments, and the application of potassium silicate and its efficiency in mitigating the attack of pests and diseases. The experiment was carried out in an agricultural greenhouse and under full sun with silicic doses of 0 and 7.15 mg per plant in a completely randomized design arranged in a 2 × 2 factorial scheme, with 6 replications of 4 seedlings per plot. Plant height, chlorophyll, stem diameter, number of leaves, shoot dry matter, root dry matter, total dry matter, height-diameter ratio, root-shoot ratio, root-plant ratio, Dickson quality index, disease severity, and pest intensity were evaluated. Silicon application did not confer biometric qualities to the seedlings. The application of silicon conferred 24.6% higher protection against disease severity at a 90% probability level. The protected environment promoted 48.8% more protection against the attack of pests on the seedlings. The silicon application decreases the intensity of pests in the protected environment by 36.3%. Seedlings in a protected environment increase the production of chlorophyll but are 29.6% more susceptible to the severity of diseases. The full sun promoted greater diameters, phytomass, and Dickson quality index by 18%, 73%, and 195%, respectively. The bestHandroanthus impetiginosusseedlings were obtained under full sun. Silicon mitigated the attack of pests and diseases onHandroanthus impetiginosusseedlings.