Peat-amended urban sewage sludge compost and plant growth stimulants for containerized culture of oleander.

In this study, the use of different rates of composted sewage sludge (CSS) in the preparation of substrates and the application of a bio-stimulant for oleander cultivation in pots was evaluated. Eight treatments were established, based on the addition of increasing quantities of CSS to peat (four growing media: CSS0, CSS10, CSS20 and CSS30, v/v) and the application via root or no (distilled water only) of an animal enzymatic hydrolysed origin bio-stimulant. Physical, physico-chemical and chemical analyses of the different mixtures of CSS and P were made. Plant growth, biomass production and visual ornamental quality were determined. The physicochemical properties of the growing media were affected by the addition of CSS. Our management system produced vigorous plants that were of marketable quality at harvest The CSS30 has allowed to obtain the best results regarding lateral shoot and plant diameter, leaf area, SPAD, dry matter content of the aerial part. Leaf and stem fresh weight and dry matter content of the aerial part has been positively influenced by the bio-stimulant application. The bio-stimulant effect was positive to obtain a good ornamental visual quality.