author(s)
Dilip Kumar, Jayant Bhatt and Ratan Lal Sharma

abstract
The root knot nematode (Meloidogyne incognita) caused significant reduction in plant height, root length fresh and dry weights of shoots and roots. Root galls and final nematode population increased with the increasing levels of nematode inoculum. Highest level of nematode inoculum indicated inhibitory and damaging potential on plant growth parameters on blackgram. Two second stage larvae of M. incognita were found to the damaging level on blackgram (Cv TU 98-14).The root knot nematode continues to penetrate at all the stages of plant growth. However, seven days old plants were observed to be most susceptible to root knot. The treatments receiving the nematode inoculation prior to fungus resulted in higher reduction and plant growth than the other treatments. When nematode inoculation was done seven days prior to fungal inoculation, it showed maximum synergistic effect followed by treatment where both the pathogens were inoculated simultaneously. Presence of nematodes not only predisposed the host but also shortened the incubation period for disease expression.