Management of Meloidogyne incognita and Fusarium oxysporum f.sp. lycopersici wilt complex using antagonistic fungi in tomato

Abstract

Two beneficial fungi viz., Paecilomyces lilacinus antagonistic to phytoparasitic nematodes and Trichoderma harzianum antagonistic to pathogenic fungi, in combination with neem cake, were evaluated for the control of the root-knot nematode Meloidogyne incognita and Fusarium oxysporum f. sp. lycopersici wilt complex. The three fungi were individually examined for variations in their growth and sporulation and their mutual interactive effects (dual culture method) on potato dextrose agar medium at 28 oC. The interrelationship between Meloidogyne incognita and F. oxysporum f. sp. lycopersici in susceptible tomato cv. Pusa Ruby, was studied and their management by the integrated approach of using P. lilacinus and T. harzianum and neem cake was evaluated in pots in a glass-house. Among the three fungi, T. harzianum PDBC TH23 grew and sporulated faster (8.8 cm in 7 days and sporulation after 7 days) than P. lilacinus PDBC PL55 (6.8 cm in 7 days and 14 days, respectively) and F. oxysporum (4.9 cm in 7 days and 18 days, respectively). In dual culture studies, the combinations of P. lilacinus with T. harzianum or F. oxysporum did not exhibit any mutual inhibition/suppression, while the combination of T. harzianum + F. oxysporum, resulted in 42% inhibition of F. oxysporum. Inoculation of M. incognita juveniles prior to Fusarium inoculation advanced the wilt of tomato by a week, while nematode inoculation after Fusarium inoculation did not increase wilting. Trichoderma harzianum controlled wilt in the presence of M. incognita for 6 weeks after transplanting. Roots of tomatoes that received P. lilacinus along with T. harzianum and neem cake were free from nematode and did not wilt till harvest. The roots obtained from these combinations were free from Fusarium fungus.