In Vitro Biocontrol of Tomato Fusarium Wilt Using Some Soil Bacteria

Fusarium oxysporum f. sp. lycopersici causer of fusarium wilt of tomato is one of the most devastating pathogens of tomato. After methyl-bromide was banned for use, other chemical treatments of soil have not been efficient enough in suppressing this disease. Therefore, using antagonistic bacteria could be the solution for ecological control of this disease. In this work, we wanted to determine antagonistic effectiveness of some bacteria in control of fusarium wilt of tomato, in vitro. Therefore, we have isolated 26 strains of bacteria from soil, where this pathogen was recorded in the past. After isolation of bacteria from soil we have determined the antagonistic effect on this pathogen using Dual culture method and calculating percentage of inhibition of radial growth of pathogen mycelia (PIRG), using formula PIRG=(r(c)-r(i)/r(c)) x100, where r(c) - radial growth of mycelia to the opposite side of petri plate, r(i) - radial growth of mycelia towards bacteria. 10 of 26 bacteria showed antagonism towards this pathogen. The greatest value of PIRG was 73,33% at A(23), followed by A(1) (69,19%), A(10) (64,44%), A(7) (54,45%), A(9) (54,13%), A(17) (53,74%). A bit lower value of PIRG was at A(22), A(20) and A(18) (51,11%). Lowest value of PIRG was 48,52% at A(5). Based on these results we conclude that antagonistic bacteria can be successfully used in control of fusarium wilt of tomato in vitro, so we will continue with identification of these and isolation of new and more effective bacteria in our further research.