Effect of Pochonia chlamydosporia formulations on root-knot nematode, Meloidogyne incognita infestation in medicinal coleus, Coleus forskohlii

Coleus forskohlii is one of the valuable medicinal plants and is infected by the root-knot nematodes, Meloidogyne spp. Affected plants produce under sized and malformed tubers. Microbial based bioformulations are one of the best solutions to contain nematode damage. Native isolate of nematophagus fungus, Pochonia chlamydosporia (TNAU PC₂-NAIMCC0039) were tested in medicinal coleus under microplot and field conditions. The results showed that the soil application of talc based formulation of P. chlamydosporia (1 x 10⁸ CFU/g) @ 1g/m² mixed with 1 kg of FYM thrice at 30-day interval showed highest reduction of nematode (62.3%) with more number of tuberous root. The formulations of P. chlamydosporia were also validated under field conditions and the results showed that the soil application of oil based formulation of P. chlamydosporia @ 1 L/ha at the time of planting followed by 30 and 45 days after planting recorded highest reduction (67.8%) of nematode population.