Comparative effectiveness of newly developed bioformulations of Trichoderma isolates against Meloidogyne graminicola in rice

The study was undertaken to achieve sustainable management of root-knot nematode, Meloidogyne graminicola infecting the rice crop. Two novel emulsion-based bioformulations of T. harzianum AMUTH-1 and T. viride AMUTV-3 were evaluated under pot conditions to test their efficacy against M. graminicola. For comparative study, pure cultures of T. harzianum AMUTH-1, T. viride AMUTV-3, and Pseudomonas fluorescens AMUPF-1, along with Nema Prime™ (Pochonia chlamydosporia, commercial powder formulation) and nematicide, carbosulfan (Marshal), were employed as standard. Pot inoculation of M. graminicola (1000 J₂/kg soil) resulted in severe galling on the rice roots (7.7 root-gall index on 0-10 scale), and significant decline in the plant growth (30%) and yield (39%) over the control. Soil application of Trichoderma bioformulations (T. harzianum AMUTH-1 and T. viride AMUTV-3) significantly enhanced the plant growth (19-25%) and yield parameters (34-39%), and reduced the galling (51-58%) and soil populations of M. graminicola (42-49%). The efficacy of these bioformulations was comparable to Marshal and superior to Nema Prime, demonstrating their potential effectiveness.