Research Publications

Asogwa, E.U


 Prospects of botanical pesticides from neem, Azadirachta indica for routine protection of cocoa farms against the brown cocoa mirid – Sahlbergella singularis in Nigeria

E. U. Asogwa1*, T. C. N. Ndubuaku1, J. A. Ugwu2 and O. O. Awe


 Accepted 11 August, 2009

The brown cocoa mirids, Sahlbergella singularis (Haglund) is the most damaging insect pest of cocoa in Nigeria. The principal means of mirid control has been, for many years, the application of synthetic insecticides on the basis of calendar spray schedule. The use of synthetic pesticides on small-scale farms in the tropics is generally not advocated because the approach lacks sustainability and raises environmental and health concerns. Most cocoa farmers simply cannot afford the cost of pesticides, despite favourable economic returns. There is therefore the need to screen for safe and effective biodegradable pesticides with non-toxic effects on non-target organisms. In the last two decades, considerable efforts have been directed towards screening of plants, (especially neem), in order to develop new botanical insecticides from the vast store of chemical substances in them as alternatives to the existing synthetics, which are associated with phytotoxicity, vertebrate toxicity, pest resistance and resurgence, wide spread environmental hazards and high costs. This review therefore looks at the prospects and utilization of botanicals for the control of major cocoa insect pests in Nigeria taking into cognizance their formulation, dosage and mode of application.

Key words: Formulation, application, dosage, sustainability, biodegradable, toxicity, hazards.



Evaluation of ethanol plant extract for protection of Cola nitida against kola weevils (Balanogastris kolae and Sophrorhinus spp) (Coleoptera: Curculionidae) in storage

E. U. Asogwa1, T. C. N. Ndubuaku1, I. U. Mokwunye1, O. O. Awe2 and J. A. Ugwu

Accepted 7 May, 2009

The kola weevils Balanogastris kolae and Sophrorhinus spp (Coleoptera: Curculionidae) are the most destructive of all kola pests. This study was designed to evaluate the protective properties of ethanol extracts of 5 plant materials each at 1x103, 2.5x103, 5x103 and 1x104 ppm, against the kola weevils on stored kolanuts. The development and emergence of adult weevils were assessed by counting newly emerged adult weevils at fortnightly intervals for 112 Days. The number of weevil exit holes on the kolanuts and the number of kolanuts with colour change in each treatment were also determined. The mean number of adult B. kolae emergence from the various extract treatments did not differ significantly from each other. However, none of the extract treatments compared effectively with the standard treatment (1.38 ± 0.25). A similar trend was observed for Sophorhinus spp, but emergence of adult weevils was extremely low (0.03 ± 0.13 to 0.34 ± 0.10), even for the control treatment (0.78 ± 0.14). There was no significance difference in the mean number of weevil exit holes recorded for all the extracts at 2.5x103, 5x103 and 1x104 ppm treatment levels. However, they all differed significantly (P < 0.05) from their control treatment (101.16 ± 11.26), but did not compare effectively with the standard treatment (8.16 ± 0.75). The mean number of kolanuts with colour changes recorded for the standard treatment (2.28 ± 0.18) differed only completely from the various treatment means of Cederela odorata (6.16 ± 0.39; 5.81 ± 0.38; 5.28 ± 0.30; 4.97 ± 0.16). Generally, there was no significant difference amongst the various extract treatments means, so none could be claimed to be superior to the other. The various extracts therefore could be proffered as alternatives to kola farmers, so as to reduce their total dependence on synthetic insecticides for kolanut storage. Storage of kolanuts at 2.5x103 ppm was found adequate and recommended taking into consideration their general protective effectiveness of the kolanuts and for economic reasons.


Key words: Kolanuts, weevils, plant extracts, treatments, emergence, exit holes, colour change.




 Pesticide-handling practices among smallholder Vegetable farmers in Oyo state, Nigeria.

Ugwu, J. A     

 Omoloye, A. A

 Asogwa, E.U              2015

 Aduloju, A.R


 Abstract- Pesticide use among smallholder farmers in Nigeria has been associated with significant health hazards. The study evaluates the pesticide handling practices among vegetable farmers in Oyo State Nigeria. Random samples of one hundred and fifty (150) vegetable farmers were interviewed using structured questionnaire in ten selected local government areas of Oyo state Nigeria. Data obtained were subjected to descriptive and inferential statistics. Majority of the farmers (74%) suffered from at least one health symptom associated with pesticide handling. However, most of them (65.4 %) claimed to have adopted the use of at least one or two safety protective equipment during pesticide application. A good number of the smallholder vegetable farmers (58.7%)do not have access to information on safety tips about pesticide handling or training on pesticide management. Cost of protective equipment and lack of training on pesticide handling seemed to be the most significant factors that influence proper pesticide handling practices among smallholder vegetable farmers in the state. It is therefore recommended that the regulatory agencies for pesticide use in Nigeria should implement the policy that will prohibit injudicious use of pesticide and provide effective training / workshop for the small holder farmers, retailers and all pesticide workers on the safety measures of pesticide application. The study also recommended integrated pest management (IPM) approaches for continued vegetable production to minimize risks associated with pesticide usage.


IndexTerms—Smallholder farmers, Pesticide management, Safety, Protective equipment, Vegetables.


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