Assessment of Azadirachta indica and Cleome viscosa liquid-formulations as bio-nematicides in the management of nematode pests of okra

The efficacy of Azadirachta indica and Cleome viscosa liquid-formulations were assessed as bio-nematicides on the performances of okra planted in nematode infested soil at Teaching and Research Farm of Ladoke Akintola University of Technology, Ogbomoso, Nigeria during 2014 planting season. NHAE-47 okra variety which, is susceptible to root knot nematodes, was the test crop. The experimental design was randomized complete block design, with 11 treatments and 4 replicates. The okra plots that were inoculated but not treated with neither bio-nematicides nor adjuvants served as the controls. The results show that A. indica and C. viscosa liquid-formulations significantly improved the growth and yield of okra planted on nematode infested soil as compared to growth and yield of okra obtained in the control experiments. The least growth rate and yield were obtained where no treatment was applied. The population of the plant parasitic nematodes (Meloidogyne, Trichodorus, Paratrichodorus, Helicotylenchus and Xiphinema) were significantly reduced on the okra plots treated with A. indica and C. viscosa liquid-formulations, when compared with plots where adjuvants and water were applied.   Key words: Azadirachta indica, Cleome viscosa, bio-nematicide, okra, nematode.