Enhancing sustainability of a processing tomato cultivation system byusing bioactive compost teas

Compost teas are compost-derived liquid products that may potentially induce positive effects on treatedcrops, including disease suppressiveness and biostimulation of the overall improved plant status. In thiswork four teas, produced from agricultural and municipal waste compost, were applied in a process-ing tomato cropping system to gain sustainable diseases management. Field trials showed that teashad a positive impact on health and vegetative status of the plants subjected to natural leaf blights, andinduced significant increases of yields. The occurrence of combined suppressive and biostimulation mech-anisms, sustained by microbial communities, nutrients supply and carbon-based bioactive compounds,was assumed to underlie the observed effects of tea on plants. Furthermore, NMR spectra suggested thatthe supramolecular organic structures contained in compost teas may be involved in the inductive pro-cesses of biostimulation, including an auxin-like activity. Molecular profiles of organic matter dissolvedin teas indicated that the interaction between hydrophobic groups and polysaccharidic moieties couldbe related to vegetative responses of treated plants. This study provides new insights concerning thecomprehension of the overall functionality of compost teas and their applicability in a timely diseasemanagement of crop systems.