Effect of urban biowaste derived soluble substances on growth, photosynthesis and ornamental value of Euphorbia x lomi

Soluble bio-based substances (SBS) isolated from municipal biowastes and a commercial Leonardite-based product were applied as substrate drench or as foliar spray to grow the ornamental hybrid Euphorbia x lomi. The SBS were found more powerful than the commercial Leonardite product in enhancing plant photosynthesis, growth and aesthetic effect, improving flower quality, and optimizing water use efficiency. Enhancement factors of plant performance indicators by SBS ranged from 1.3 to 8.6 relatively to the control plants, and from 1.2 to 4.5 relatively to plants treated with the commercial Leonardite product at equal applied dose. The environmental and economic implication of these results for agriculture, the management of urban wastes, and the chemical industry are discussed.