Changes in the phenolic contents, related rhizosphere mycoflora and nematode population in tomato inoculated with Meloidogyne incognita as a result of soil amendment with organic matter

Amending the soil with sawdust, urea, cowdung, leafmold, castor, mustard and neem cakes was found effective in reducing the development of Meloidogyne incognito on tomato. However, mixture of sawdust with different oilcakes improved the growth of plant and reduced the infestation of root-knot nematode. The adverse effect of sawdust on plant growth was mitigated by addition of different nitrogen sources. Total free phenols, O-dihydroxyphenols and amino acids content increased in infected plants grown in amended soil. Frequency of saprobic fungi increased in all the treatments except in sawdust, however, the frequency of parasitic fungi decreased.