Study on the biological control of fusarium wilt of tomato

In present study, the effect of a root colonizing fungus Penicillium sp. EU0013_90S as biocontrol agent (BCA) against Fusarium wilt pathogens was observed in dual culture experiment as well as under screen house conditions. Dual culture experiment was conducted to see whether EU0013_90S has an inhibitory effect on different fungal pathogens especially Fusarium wilt pathogens e.g. Fusarium oxysporum f. sp. lycopersici race 1 CU1, race 1 MAFF 305121, and race 2 JCM. The radial colony developments of the pathogens were inhibited by zone of different lengths. In screen house experiment, different conidial concentrations (1×104, 1×105, 1×106 ml-1) of Penicillium sp. EU0013_90S were treated with tomato seedling followed by Fusarium wilt pathogens of tomato (JCM, MAFF) having different conidial concentrations (1×105, 1 ×106, 1×107 ml-1) A week after the treatment, tomato plants were observed for external symptoms. Stunting, yellowing and wilting of leaves were caused by Fusarium oxysporum isolates (JCM, MAFF). Disease severity was assessed through visual observation. The data was taken with two days interval for 24 days. Treatment of tomato plants with EU0013_90S resulted in significant disease reduction. Disease reduction varied with the different conidial concentrations of BCA and the Fusarium wilt pathogens (JCM, MAFF) used. The highest disease reduction (95.24% and 80.58%) occurred in the treatment where BCA was applied at lowest conidial concentrations (1×104 conidia ml-1) with JCM and MAFF respectively.