Pathogenic Potential of Meloidogyne incognita on Mentha arvensis cv. Gomti

Studies were made to determine the effect of initial inoculum levels (Pi) of Meloidogyne on Mentha arvensis cv. Gomti. There was a positive relationship between the initial inoculum levels of M. incognita and reduction in shoot-root/sucker fresh and dry weights, oil yield, total chlorophyll, total phenol and total sugar content of fresh leaves. The maximum reduction in corresponding parameters was recorded at the highest initial inoculum level (25,000 J2/5 kg soil) as compared to uninoculated control. There was a negative relationship between initial inoculum densities and rate of nematode multiplication. Maximum nematode final population Pf (1,33,430) and root-knot index (3.00) were observed at the highest Pi (25,000 J2/5 kg soil), whereas, maximum reproduction-factor was observed at minimum Pi (500 J2/5 kg soil).