Nematicidal potential of aqueous extract of Hyptis suaveolens in the management of root-knot nematode, Meloidogyne incognita of some cowpea cultivars

Studies were conducted under field and screenhouse conditions to investigate the potentials of crude aqueous leaf extract of Hyptis suaveolens in the management of the root-knot nematode Meloidogyne incognita of three cowpea varieties (Sampea 9, 10 and 11). A Randomized Complete Block Design was used in the field while a completely randomized design was used for the screenhouse trials. Results showed that the treatment significantly (p < 0.05) improved the growth and yield of the three varieties and also reduced soil nematode population and root galls. It was also observed that all the three varieties were susceptible to the root-knot nematode infestation but Sampea 10 recorded higher yield that were significant in the pot trials. Phytochemical screening revealed the presence of saponins, alkaloids, flavonoids and steroids in the leaves of H. suaveolens. For higher yield of the evaluated cowpea varieties in a nematode endemic zone, aqueous leaf extract of H. suaveolens is being recommended for infested soil treatment