Effect of four plant extracts on the infestation of cowpea (Vigna unguiculata (L.) walp) by Megalurothrips sjostedti (Trybom) and Mylabris pustulata (Thunberg)

Field studies were conducted on cowpea variety 87-9TDK, planted at 60 x 30cm spacing at the Teaching and Research farm of College of Crop and Sciences, Michael Okpara University of Agriculture, Umudike, in the rain forest ecological zone of Nigeria during the 2001 cropping season. The experimental design was a randomized complete block design (RCBD) with four replications. Hot water extracts from the milled leaves of Ocimum grattissimum, Vernonia amygdalina, Azadirachta indica and Chromolaena odorata controlled the cowpea field pests investigated. Two grammes per litre concentration of the crude plant extracts reduced the insects infestation and significantly (P< 0.05) increased yield. Azadirachta indica and Ocimum grattissimum were the most effective of the plant materials used.Keywords: plant extracts, cowpea, Megalurothrips sjostedti, Mylabris pustulata, control Global Journal of Pure and Applied Sciences Vol. 12(1) 2006: 19-2

Effect of combination of some plant powders on the control of Sitophilus Zeamias Motsch

No Abstract.Nigeria Agricultural Journal Vol. 35 2004: pp. 76-8

Contribution of different constituents to the toxicity of the essential oil constituents of Vernonia amygdalina (Compositae) and Xylopia aetiopica (Annonaceae) on maize weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)

The lethal toxicity of the major constituent of the essential oils of Vernonia amygdalina and Xylopia aetiopica, and of selected blends of these against Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) was compared with those of the full blends of the essential oils. The compounds were assayed in amounts and proportions present in the minimum 100% lethal dose of the essential oils. The major component of X. aetiopica was found to be largely responsible for the toxic action of its essentialoil against S. zeamais, On the other hand the toxic action of V. amygdalina was due to the combined effects of its constituents, either with or without significant individual toxic action of their own against the insects. The implication of these results and their implication in screening and using plants and their phytochemicals for S. zeamais control is highlighted

Essential oil of Ocimum grattissimum (Labiatae) as Sitophilus zeamais (Coleoptera: Curculionidae) protectant

Ocimum grattissimum L. (Labiatae) leaves are widely eaten as a vegetable in Nigeria, and in the eastern parts, are traditionally used in post-harvest protection and relieving stomach aches. The effect of theessential oil of O. grattissimum leaves on Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) was assessed for repellency, mortality, progeny emergence and maize damage in the laboratory. The oil was found to be moderately repellent to the maize weevil and induced high mortality in the weevils. In addition, grains treated with the essential oil showed significant reduction in the number of progeny derived from surviving S. zeamais. There was no observable feeding damage on grains treated with the highest dosage of the essential oil extract. Gas chromatography-linked mass spectrometry (GC-MS) and GC co-injections with authentic samples showed the presence of the following major constituents: thymol (32.7%), paracymene (25.4%), -terpinene (10.8%), -selinene (4.5%), phellandrene (3.9%) and - myrcene (3.1%). The results provide a scientific rationale for the use of the plant in post-harvest protection

Insecticidal effects of powdered parts of Eight Nigerian plant species against maize weevil Sitophilus zeamais motschulsk (Coleaoptera: Curculionidae)

No Abstract.Nigeria Agricultural Journal Vol. 37 2006: pp. 106-11