Herbal leaf powders efficiently manage root-knot nematode of okra

Root-knot nematode is a devastating pathogen of vegetables. Okra (lady's finger, Abelmoschus esculentus) is reported to face up to 90.9% loss of yield due to Meloidogyne incognita. In preliminary trials 19 plant species belonging to weeds, aromatic plants, shrubs and trees were tested for their potential as toxicants for root-knot nematode of which 17 plant species were found effective. Due to year round availability neem (Azadirachta indica), Jatropha (Jatropha curcas), dhatura (Datura metel) and custard apple (Annona squamosa) were selected for evaluation of dry leaf powder as soil amendment. Dry leaf powders applied as 5, 7.5 and 10% doses (w/w) have shown significant reduction in nematode population. A. indica 10% and J. curcas 10% had resulted in 96.5% reduction of nematode population over control when observed after completion of one life cycle by pathogen i.e. 42 days of inoculation. Maximum improvement in plant growth parameters was observed with A. indica 10% dose.