The sweet orange, Citrus sinensis L. is an important fruit crop in Nigeria and its production is seriously constrained at maturity by attack of the fruit fly, Ceratitis capitata which results in severe yield loss. Effects of attack by C. capitata on fruit morphology and nutritional characteristics of C. sinensis from selected sites in southwest Nigeria were investigated. Twenty five mother citrus trees with >45 cm diameter at breast height (DBH) were randomly selected at two plantation sites: Ede (Osun state) and Olodo (Ogun state) in southwestern Nigeria. Ten mature fruits, plucked randomly from four cardinal sections of each tree were classified based on levels of infestation. Effects of attack on fruit morphometrics were assessed by standard measurements while the effects on fruit quality were determined by proximate and mineral analyses. Results indicated that attack by C. capitata was characterized by oviposition punctures which predisposed the fruit to secondary infection by Penicillium notatum. Fruits were attacked at any point on the surface but significantly more at about 2 cm from the fruit stalk scar. Multiple attacks did not follow a regular pattern. Fruit attack by C. capitata significantly decreased moisture content of fruit by 79% and mineral content; calcium, phosphorous, copper, zinc and iron while percentage dry matter, crude protein and crude fiber decreased significantly (P<0.50) with increased infestation. Fruit infestation also caused significant decrease in the vitamin C content by about 50% but increased saccharose, maltose and glucose content of attacked fruits by about 10%.
Native entomopathogenic nematodes (EPNs) were evaluated for the management of three selected pests, Sesamia calamistis, Spodoptera frugiperda and Rhynchophorus ferrugineus in laboratory bioassays. The EPNs were isolated from soils from various locations within Ibadan, Nigeria using the greater wax moth (Galleria mellonella) as insect bait. A two-factor laboratory experimental assay was laid out in a completely randomized design and replicated three times. The EPN suspension was applied on insect larvae with distilled water as control. Number of days to mortality, percentage mortality of insect larvae, and total EPN population of infective juveniles (IJs) recovered from larval cadavers were assessed and reproductive factor (RF) determined. Data were analyzed using analysis of variance, and means were separated using Tukey's Studentized Range Test at P<0.05. The number of days to mortality for inoculated larvae of S.
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
Background
The uses of botanical pesticides in pest management are currently on remarkable increase due to their efficacy, biodegradability, environment-friendly, and availability. Ethanol extracts of three spices (Piper guineense, Aframomum melegueta, Zingiber officinale) and commercial botanical pesticide AzaSol (6% azadirachtin) were assessed for contact toxicity, residual effects, and for their potential in soil application against pupariating larvae of oriental fruit fly (Bactrocera dorsalis) in the laboratory at ambient temperature of 27 ± 2 °C and relative humidity of 75–80%. The extracts and AzaSol were applied at 1:1.5 w/v concentration while cypermethrin was introduced as standard check and applied at 5 ml/liter of water.
Results
All the treatments were very effective against B. dorsalis in contact toxicity and residual affects recording 89.4–100% larval mortality at 24 h post-application. Z. officinale and cypermethrin had similar contact and residual effects on B. dorsalis, both recording 100% larval mortality at 24 h post-exposure. Piper guineense showed higher residual effects than contact effects, while A. melegueta and AzaSol showed better contact effects than residual effects against B. dorsalis larvae. AzaSol was the most effective among the botanicals in reducing the adult emergence and in enhancing larval mortality (96.7%) on treated soil followed by Piper guineense (83.3%). The efficacy of AzaSol on the treated soil was comparable to cypermethrin. All the extracts were significantly more effective than control in enhancing pupariating larvae mortality and in reducing adult emergence on treated soil.
Conclusion
Ethanol extracts of P. guineense and A. melegueta were highly promising against B. dorsalis on treated soil and could be adopted in soil application targeting puparia under the tree canopies as part of integrated pest management of B. dorsalis in orchards.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.