Evaluation of isolates of Bacillus-group against Fusarium oxysporum f. sp radicis-lycopersici on tomato plants in soilless culture

The pathogen Fusarium oxysporum f. sp. radicis-lycopersici (FORL) causes crown rot and root rot and is widespread and serious in commercial greenhouse cultivated tomato. Young tomato plants can be infected with contaminated irrigation water. The treatment of plants with antagonistic bacteria is a possibility of pathogen control. The selection of effective bacteria strains against FORL was concentrated especially of isolates of Bacillus-group. Bacteria strains were isolated from tomato cultivated in soilless culture. The antagonistic activity of bacteria strains was tested against different formae speciales of F oxysporum. The Fusarium-isolates showed a different sensitivity against the antifungal compounds of a bacteria strain. The inhibition of the mycelial growth was influenced by the test media. Bacteria strains with antagonistic effects in vitro were tested on plants under greenhouse conditions to control FORL on tomato. The treatment of tomato plants with some strains resulted in reduced disease incidence by FORL on tomato in experiments replicated. The strains were members of the Bacillus-group and for such strains a formulation technology exists. Formulated products can be used in plant protection strategies for soilless culture.