author(s)
Jothi G and Poornima K

abstract
The effect of humic acid on hatching, mortality, host plant infection and galling of root knot nematode, Meloidogyne incognita were investigated at the glass house, Department of Nematology, Tamil Nadu Agricultural University, Coimbatore, India during June 2015. Different concentrations of humic acid (0.2% to 1%) were tested for their influence on egg hatching and juvenile mortality of Meloidogyne incognita in vitro. Humic acid at all the concentrations tried, caused significant inhibition in egg hatching and recorded cent percent inhibition of egg hatching at 1% concentration. Penetration of nematodes was delayed by 4 days after innoculation. The number of nematodes penetrated the roots were 5 % on the 4^th day and gradually increased and was 15 % from the 8^th day onwards. Percent J₂ mortality of M. incognita increasing with per cent concentration of humate showed positive relationship. It is optimized that humic acid at 0.4% is effective to cause higher juvenile mortality (93%) with comparatively shorter period of exposure (48h).