Biocontrol ofAlternaria alternataandFusarium oxysporumbyTrichoderma asperelloidesandBacillus paralicheniformisin tomato plants

The objective of this work was to evaluate the effectiveness of the putative biocontrol agents (PBA)Bacillus paralicheniformisandTrichoderma asperelloidesin vitro and in vivo to control two of the most important tomato plant diseases: vascular wilt (Fusarium oxysporum) and early blight (Alternaria alternata). The assessment of the in vitro interactions between the PBA and the phytopathogenic fungi was performed by dual confrontation assays. The biocontrol effectiveness of the individual and combined PBA treatments towards individual phytopathogen inoculations was evaluated in tomato plants.T. asperelloideswas able to exert an outstanding mycoparasitic effect on both phytopathogenic fungi in the in vitro tests by hyphal strangulation and penetration. In addition, the individual PBA treatments were effective in the biocontrol ofA. alternataandF. oxysporumin tomato plants reducing the plant disease severity in more than 53.8 and 66.7% for each of the pathogens, respectively. On the other hand, the combined use of the tested strains showed similar effectiveness in the biocontrol ofA. alternata, but no synergism was observed. In addition, it was concluded thatB. paralicheniformisprotected the plants from the attack ofA. alternatathrough the induction of the systemic resistance of the plant. This study demonstrated the effectiveness of the individual and combined use of the strains tested for the biocontrol ofA. alternataandF. oxysporumin tomato plants.