SUPPRESSIVE ACTIVITY OF ORGANIC AMENDMENTS ENRICHED WITH MICROBIAL ANTAGONISTS AGAINST FUSARIOSIS OF TOMATO AND CUCURBIT PLANTS

"Cucurbits and solanaceous plants are widespread and economically. important horticultural crops often attacked by different. pathogens, among which soil-borne fungal pathogens are responsible. for severe root and crown rots. Chemical control of soilborne. pathogens using synthetic fungicides is often uneconomic. and involves technical and eco-toxicological negative side effects.. Research on safer and environmentally-friendly alternative control. means are then of particular interest. As emerging alternatives,. new plant growth media enriched with microbial antagonists may display an interesting suppressive activity. In the present study, the. suppressive activity of organic amendments, alone or enriched. with microbial antagonists was tested against Fusarium oxysporum. f. sp. lycopersici and F. oxysporum f. sp. melonis, the causal agents. of tomato and cucurbit fusariosis, respectively. In blind trial experiments. on tomato and melon plants, four organic amendments. enriched with selected microbial antagonists and used in mixture. (up to 10% v\/v) with a standard plant-growth substrate were assayed.. Trials were conducted on potted plants grown under controlled. conditions and in commercial nurseries and the following. parameters were periodically assessed: disease incidence and. severity; pathogen isolation from plant tissues; survival of microbial. antagonists in the rhizosphere; effect of the treatment on. plant growth. On both tomato and melon, some enriched amendments. induced a significant reduction of Fusarium disease incidence. and severity as well as positive effects on plant growth. Furthermore,. microbial antagonists added to the amendment survived. in the rhizosphere at a high population level."