Showing papers on "Xylopia aethiopica published in 1996"

The efficacy of four seed powders and the essential oils as protectants of cowpea and maize grains against infestation by Callosobruchus maculatus (Fabricus) (Coleoptera: Bruchidae) and Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) in Nigeria

Abstract: Seed powders and the essential oils of Dennettia tripetela Baker F., Piper guineense Schum and Thonn, Mondora myristica (Gaerth) Dunal and Xylopia aethiopica Dunal A. Rich were evaluated for their effectiveness in protecting cowpea and maize grains during storage. D. tripetela powder mixed with maize grains, at 1.5 g per 25 g was significantly more effective (P < 0.05) than P. guineense, M. myristica and X. aethiopica in achieving 100% mortality of adults of Sitophilus zeamais in 24 h, and was also as effective as pirimiphosmethyl (10 ppm) in achieving 100% mortality of adult weevil in 24 h, 3 months after treatment at a dose of 3g per 25 g. There was no F1 emergence except in grains treated with M. myristica, X. aethiopica and the untreated controls. Essential oils of D. tripetela and P. guineense achieved 100% mortality of adults of Callosobruchus maculatus and Sitophilus zeamais in 24 h. Except in cowpea treated with X. aethiopica cowpea and maize grains treated with seed oils suppressed the e...

High incidence of Aspergillus flavus and aflatoxins in stored groundnut in Ghana and the use of a microbial assay to assess the inhibitory effects of plant extracts on aflatoxin synthesis.

Abstract: Groundnut samples from 21 selected markets in the 10 regions of Ghana yielded high levels of the aflatoxigenic fungus Aspergillus flavus on half-strength potato dextrose agar. The fungus was associated with 31.7 and 12.8%, respectively, of all damaged and undamaged kernels assayed. Only 0.24% of total kernels assayed yielded A. parasiticus. Other fungi detected from total kernels assayed were A. niger (34%), A. candidus (1.45%), A. tamarii (3.93%), A. ochraceous (5.26%), Fusarium spp. (1.7%) Penicillium spp. (5.19%), a Mucor sp. (2.3%), a Trichoderma sp. (0.2%), Rhizopus stolonifer (12%) and certain unidentifiable fungi (11.72%). Total aflatoxin levels ranging from 5.7 to 22, 168 ppb were identified with damaged kernel samples. The mycotoxin was not detected in 50% of undamaged kernel samples tested and very low levels mostly ranging from 0.1 to 12.2 ppb were associated with the undamaged samples that tested positive for aflatoxins. In a novel in vitro microbial assay to determine the effectiveness of certain plant extracts against aflatoxin synthesis, extracts from Xylopia aethiopica, Monodera myristica, Cinnamomum verum and Piper nigrum permitted fungal growth in 1.5% potato-dextrose broth while completely suppressing NOR formation. These extracts, however, could not suppress NOR formation in a yeast extract sucrose medium.

Biological activities of extracts from traditionally used Nigerian plants against the European corn borer, Ostrinia nubilalis

Abstract: Preliminary investigations with ethanolic (EtOH) extracts from five Nigerian plants show that extracts of Piper guineense Schum and Thonn (Piperaceae), Cedrela odorata L. (Meliaceae), Dennettia tripetala G. Baker (Annonaceae) and Aframomum melegueta (Rosch) K. Schum (Zingiberaceae) in artificial diets significantly reduced larval growth of European corn borer (ECB), Ostrinia nubilalis Hubner, at a concentration of 1000 ppm (0.1%). An extract of Xylopia aethiopica (Dunal) A. Rich (Annonaceae) was ineffective. When the extracts were subsequently incorporated into artificial diets at 300 ppm and offered to neaonates, larval mortality increased in the order A. melegueta (13%), D. tripetala (13%), P. guineense (27%), and C. odorata (48%). Larval and adult emergence periods increased with increasing concentration of P. guineense, C. odorata and D. tripetala indicating a toxic response. Nutritional indices for habituated third instar larvae with the two most promising plant extracts, P. guineense and C. odorata, showed that the efficiencies of conversion of digested food (ECD) was significantly reduced at 300 ppm suggesting a postdigestive toxicity of the extracts. P. guineense and C. odorata extracts show the best potential for development as botanical insecticides.

Influence of fruit conservation methods on the essential oil composition of Xylopia aethiopica (Dunal) A. Richard from Benin

Abstract: The fruits of Xylopia aethiopica (Dunal) A. Richard (Annonaceae) from Benin, commercially conserved in two different ways, were subjected to steam distillation. The resulting essential oils were analysed by high-resolution GC and HRGC-MS. For comparison, the leaf oil and fresh fruit oil of X. aethiopica were analysed as well. The oils were found to contain 50-60 components, of which about 40-45 constituents have been identified, accounting for more than 95% of the oils. The major components appeared to be α-pinene (4-16%), sabinene (3-35%), β-pinene (12-42%), 1,8-cineole (trace-15%) and (Z)-β-ocimene (trace-18%). The leaf oil contained, in addition to these constituents, 14.9% of elemol

Composition of the Essential Oil of Xylopia aethiopica Dried Fruits from Benin

Abstract: Forty one compounds have been characterized by GC/MS and relative retention times in Xylopia aethiopica oil obtained by hydrodistillation of dried fruits collected in Benin (West Africa). Among them, sabinene (36.0%), 1,8-cineole (12.8%), linalool (3.9%), and terpinen-4-ol (7.0%) were the main components.

Identification of the Components of the Seed Oil of Xylopia aethiopica from Guinea Using 13C-NMR Spectroscopy

Abstract: Identification of the components of three samples of Xylopia aethiopica essential oil from Guinea was carried out using 13C-NMR spectroscopy. The main constituents found for all samples were β-pinene and α-pinene. Sabinene and 1,8-cineole were also found in two of the oils, while α-phellandrene and germacrene-D were found in the third sample.

Fungitoxicity spectra of crude extracts of three Ghanaian medicinal Plants

Abstract: Steam distillates from three Ghanaian medicinal plants, Ocimum gratissimum (L.), Xylopia aethiopica (Dunal) Rich and Cymbopogon citratus (D.C.) Stapf, were tested for fungitoxicity against 20 fungal species. A fungitoxicity spectrum (FS) was calculated for each extract based on per cent inhibition of fungal growth. High FS values of 4.8 and 3.5 (maximum assignable value = 5) were, respectively, associated with extracts of O. gratissimum and C. citratus. A low value of 1.4 was recorded for X. aethiopica. Whereas extract of O. gratissimum exhibited complete fungicidal activity towards 14 of the 20 fungi, that of C. citratus was fungicidal to only three. The extract of X. aethiopica was fungistatic but not fungicidal. (Ghana Journal of Agricultural Science, 1996, 29(2): 71-74)