Potentials of Aqueous Extract of Pod Husk Parkia biglobosa (Jacq.) Benth as a Biopesticide in Okra (Abelmoschus esculentus (L.) Moench) Production

Abstract

Aims:This study evaluated potentials of aqueous extract of pod husk of Parkia biglobosa as a biopesticide in okra production. Study Design: The study employed a radomized complete block design with seven treatments (5, 10, 15 and 20% Parkia biglobosa aqueous pod husk extract (PPHE), 2.5 ml dimethoate + cypermethrin (D+C) -recommended, 5.0 ml (D+C), control -500 ml of water) and replicated three times. Place and Duration of Study: Crop Garden of Department of Crop Protection and EnvironmentalBiology, University of Ibadan (7° 34'N and 3° 54'E) between April and July 2016. Methodology: The leaves, seeds, pod husks and bark of Parkia biglobosa were collected, authenticated and analyzed for their phytochemical compositions using standard procedures. Fayinminnu et al.; JAERI, 12(1): 1-12, 2017; Article no.JAERI.32529 2 Aqueous extract of the pod husk of the plant (PPHE) was found to contain the highest phytochemicals qualitatively and quantitatively which formed the basis of using it as a biopesticide. A field study was conducted at the crop garden of Department of Crop Protection and Environmental Biology, University of Ibadan, to assess the potency of the extract as a biopesticide and a synthetic insecticide -Dimethoate 14.5% + Cypermethrin 5.5% (D+C) on the management of flea beetles on NHAe-47-4 okra variety. The seven treatments (5, 10, 15 and 20% Parkia biglobosa aqueous pod husk extract (PPHE), 2.5 ml dimethoate + cypermethrin (D+C)recommended, 5.0 ml (D+C) (synthetic), control -500 ml of water) were applied weekly on okra plants from two Weeks After Sowing (WAS) till 12 WAS. Data were collected on growth and yield parameters, dry matter accumulation of A. esculentus and flea beetle populations. Data were analyzed using descriptive statistics and ANOVA at P = 0.05. Results: Results revealed that treatment 20% PPHE had relatively higher values of growth parameters which compared favorably (p≤0.05) with 2.5 ml and 5 ml (D+C). Yield parameters; Number of fruits and fruit weights from 20%PPHE also compared favorably with 2.5 ml and 5 ml (D+C) with no significant difference (P >0 .05) and with the same trend in dry root weight. While the dry shoot weight of 2.5 ml (D+C) treatment (p≤0.05) was different from other treatments. The control treatment however, revealed significant differences (p<0.05) in having reduced growth and low yield when compared with the treated plots. Conclusion: This study showed the efficacy and potency of Parkia biglobosa aqueous pod husk extract (PPHE) in suppressing the flea beetles due to its highest quantities of phytochemicals. The 20% concentration also enhanced the growth and yield of okra and performed relatively well with the recommended dose (2.5 ml) of D+C. The aqueous pod husk extract, therefore could serve as a biopesticide for food sustainability and safety. Original Research Article

Genus Parkia: Phytochemical, Medicinal Uses, and Pharmacological Properties

“…Various phytochemicals are found in the stem barks, leaves, seeds, and pods of these plants. The stem bark of P. biglobosa is reported to contain phenols, flavonoids, sugars, tannins, terpenoids, steroids, saponins [ 11 , 38 ], alkaloid, and glycosides [ 35 , 43 , 45 ], while the leaves contain glycosides, tannins, and alkaloids in trace amount [ 11 , 23 , 46 ], in addition to flavonoids, phenols, and anthraquinones [ 47 ]. Phytochemical screening of the seeds shows the presence of saponins, alkaloids, flavonoids, polyphenols, terpenoids, glycosides and tannins [ 48 , 49 ].…”

Qualitative and quantitative phytochemical evaluation of Quassia undulata (Guill. & Perr.) D. Dietr. leaves using different solvent polarities

“…The leaves were washed by placing them under running water, they were air dried at room temperature for about two weeks; the dried samples were pulverized and stored in an air tight container prior to extraction. Amount of 20 g of the sample was soaked in 100 mL of each of the solvents in the ratio 1:5 (Fayinminnu et al, 2017). The mixture was stirred at intervals and filtered after 72 hours (Osibemhe and Onoagbe, 2015); the solvents were removed by means of a rotary evaporator at 40 °C under reduced pressure (Adeniyi, 2019).…”