Biological control of root knot nematode, Meloidogyne incognita , in vitro, greenhouse and field in cucumber

Aspergillus flavus, Penicillium chrysogenum and Pochonia chlamydosporia as culture filtrates applied alone and in combinations in vitro and in planta green house and field studies against M. incognita using cucumber cultivar "Beith alpha". In vitro study conducted on M. incognita, cumulative percent hatch inhibition and J2s mortality of M. incognita reached to 100% over 72 h of incubation in spring, 2014 and 2015 by fungal bio-agent combination viz., P. chrysogenum + P. chlamydosporia. All the fungal bio-control agents significantly suppressed M. incognita on cucumber in green house and field trials. The fungal bio-control agent combination viz., P. chrysogenum + P. chlamydosporia had the greatest effects on nematode galling indices, egg masses and adult females per 10 g of cucumber roots and substantially reduced the reproductive factors in both year greenhouse experiments. Field trials conducted under natural field infestation at Dargai, filtrates of the fungal bio-agent combination P. chrysogenum + P. chlamydosporia reduced the nematode parameters and enhanced the plant growth parameters of cucumber in the spring, 2014 and 2015 years trials with attendant yield increase. These data suggest that filtrates of fungal bio-agents viz., A. flavus, P. chrysogenum and P. chlamydsporia could be used alone or in different combinations in an integrated pest management as an effective strategy for M. incognita.