Comparative evaluation of powdered and aqueous extract of citrus peels and carbofuran in the management of root-knot nematode on infected cowpea field

Sa？etak Two years of experimental trials were conducted in Nigeria to investigate the effect of powdered and aqueous extract of citrus (sweet orange) peel in the management of root-knot nematodes of cowpea cultivar ‘IT96D-610’. Different concentrations of aqueous citrus (sweet orange) peel extracts were used as well as different amount of citrus (Sweet Orange) peel powder. As a standard check carbofuran was used. Furthermore, phytochemical screening was carried out to determine the presence of secondary metabolites, while GC-MS was used to identify the presence of some chemical compounds. Results in the present study showed, that the treated plants performed significantly higher than the untreated counterparts in terms of growth, yield and reduction of soil nematode population. Phytochemical screening of the secondary metabolites revealed the presence of tannins, saponins, flavonoids, glycosides, sterols and alkaloids while the analysis by GC-MS revealed the presence of citral and β-caryophyllene to be the prevalent compounds. These compounds might be responsible for the control of root-knot nematode infecting cowpea since they exhibited nematicidal potential in their activitie