Comparative efficacy of organic amendments and a nematicide on population dynamics of Tylenchorhynchus brevilineatus, microbial activity, groundnut pod disease and yield

The efficacy of different organic amendments on the population dynamics of plant parasitic nematodes including Tylenchorhynchus brevilineatus, microbial population (total fungi, bacteria, actinomycetes) and the pod disease severity of groundnut was compared with carbofuran. The maximum reduction in T. brevilineatus was recorded in sawdust (25 q/ha) supplemented with nitrogen (30 kg/ha), phosphorus (40 kg/ha) and potassium (50 kg/ha), followed by neem cake (10 q/ha), poultry manure (50 q/ha), farm yard manure (100 q/ha), sugar factory pressmud (25 q/ha), groundnut cake (10 q/ha), and castor cake (10 q/ha). T. brevilineatus population was correlated positively with the pod disease index. The maximum increase in saprozoic nematode population was recorded with sugar factory pressmud. The total soil microflora was negatively but non-significantly correlated with the per cent disease index. The maximum increase in the fungal and bacterial population was recorded in farm yard manure treatment and the highest in actinomycetes population in sugar factory pressmud.